|
3h. When things don't work: Infrared Optic Switches
If a WPC game is not listed below then the game did not use optic switches for the flippers. Note the type1 and type2 interuptors (either plastic or metal) are not interchangable between type1 and type2 flipper optic boards. Type 1 (interuptor slot runs vertical). Originally used in:
Type 2 (interuptor slots runs horizontal). Originally used in:
Where Optos are Used. Two parts to a opto switch. On non-U shaped optos, usually the transmitter LED is mounted in a WHITE plastic case with a small GREEN printed circuit board. The receiver is usually mounted in a BLACK plastic case with a small BLUE printed circuit board.
Optos can get dusty from the "black dust" inside a game. To clean an opto, use a Q-tip dipped in glass cleaner. Wipe the opto with the Windex-wet Q-tip, then dry the opto with a clean, dry Q-tip. Do NOT use canned air to blow optos clean! The air in these cans is too cold and can damage an opto. Testing Opto Switches.
If an opto switch doesn't work, first check that the +12 volts is working. If you have blown the +12 volt fuse (either the unregulated 12 volts which provides power directly to the optos, or the regulated 18/12 volts which provides power to the entire switch matrix), the optos won't work. Check fuses F115 and F116 (F101 and F109 on WPC-95) on the power driver board. Also if the unregulated +12 volts is below about 11 volts, the optic switches can work intermittently! If this is the case, usually it indicates a bad BR5 bridge rectifier on the driver board (or bad 12 volt D3-D6 rectifying diode on WPC-95; see the Reset Section of this document for more information on this). BR5/D3-D6 is the unregulated 12 volts (where BR1/D11-D14 is the regulated 12 volts, which could also be the problem since this powers the entire switch matrix, which ultimately reads the opto switches). Remember there is also a large 10,000 or 15,000 mfd filtering capacitor C30 (C8 on WPC95) associated with the power driver board's unregulated 12 volt rectifiers. Check that too for cracked solder joints around the capacitor's leads from vibration (often I will run jumpers to the capacitors and bridges, as shown in the Reset section of this document). Testing the Opto Transmitter. If there is +12 volts going to the transmitter opto but the switch does not work, there is a good chance the transmitter LED has failed. Radio Shack sells a $5 credit card sized "infrared sensor". MCM Electronics also sells one, #72-6771, for about $7 (800-543-4330 or www.mcmelectronics.com). If you put this card right in front of an opto transmitter, the opto's emitting light can be seen; the light will show on the colored band of the sensor card. Also, a digital camera or a camcorder will usually show infrared light from the transmitting opto, if the digital camera has a small LCD screen used to show images "live" (but personally I like using the opto cards better). If there is +12 volts (hint: do other optos work?), and the opto switch doesn't register in the diagnostic test, your opto transmitter is probably burnt. The receiver side of an opto switch rarely dies. That's because it only senses light, and doesn't produce light. The transmitter will be the offending unit 98% of the time. Remember the opto transmitter is powered-on all the time the game is turned on, and it can burn out just like a light bulb can burn out. Reversed Leads on the Transmitter. Testing the Opto Receiver. Another way to test the opto receiver is using a DMM. First block the opto transmitter with a piece of black electrical tape. Put the black DMM lead on ground (the metal side rail of the game works well). Put the red DMM lead on one leg of the opto receiver (gray wire). One opto receiver leg should show 12 volts DC, and the other opto leg should show close to zero volts (orange wire). Keep the red DMM lead connected to the "low" (zero volt) opto leg. Now shine a flashlight into the opto receiver. The DMM should now go to 12 volts DC, and when the light is removed, go back to near zero volts. If this does not happen, the opto receiver is bad. Or if 12 volts is seen on both opto receiver legs, the receiver is bad (or there is direct light shining into the opto receiver).
Older WPC games use optos with straight resistive photocells. Some newer WPC95 games use a transistor gate photocell. This means the internal transistor can die, even if the photocell part of the opto is OK. Keep this in mind; if an opto transmitter tests good (with your Radio Shack or MCM test card), the opto could still not function properly. Replacing the opto is the only thing that will fix it. This is rare and hard to diagnose, but if everything checks out this could be the problem. Opto Board (the Opto Receiver and Transmitter Tests Good, now
what)? I typically do this (for non U-shaped optos) by taking a new opto (receiver or transmitter), and holding its legs to the back of the opto board. For the transmitter I can check it with a digital camera or an opto sensor card. For a receiver I can test it with a penlight (or the other tests given above). Unfortunately if the opto board has a problem, these tests may not work... Most of the newer WPC games have a seperate board mounted under the playfield called an "opto board". These have some LM339 voltage comparitor chips and diodes and resistors. If this board fails it can really confuse the game. Also games Indiana Jones to Demo Man usually have an opto board under the playfield AND the trough board is essentially a second opto board. Both these board have LM339 chips, which can be problematic. (After Demo Man starting with WCS94, the trough opto boards no longer have LM339 chips, as these were all moved to the under-playfield mounted opto board. So the trough opto board becomes less of an issue.) There are many different 'flavors' of these opto boards, so it's hard to give an exact test for the opto board. But there are some general things that should be looked at:
If everything checks out, that only really leaves one thing left: the LM339 chips on the opto board. I generally replace all the LM339 chips (and use sockets!) on the opto board (there are usually two to four of these chips on the opto board). Unfortunately the LM339 chips are not that easy to test, since they're dealing with voltage levels. But as long as the voltage levels on the outputs of the LM339 are stable (not pulsing and not fluctuating), the truth table for the individual comparators can be tested with a DMM (inputs) and a logic probe (output). Other Problems. Flipper opto boards were implemented on Addams Family, mid-production. If a WPC Fliptronics flipper doesn't work, and it's not a coil, transistor or wiring related problem, you should suspect the flipper opto board. This board has two "U" shaped optos that detects the flipper button. These boards are all made with two optos, even if the game only has two flippers instead of four. Use the infrared sensor card to determine if the opto is working on the flipper board. If you suspect a problem with this opto (and don't have a infrared sensor card), swap the left and right flipper opto boards, and see if the problem moves to the opposite flipper. Note: both flipper opto boards must be plugged in for this test to work! Flipper opto power is run from the backbox, through the left flipper opto board, to the right flipper opto board. Flipper opto ground is run from the backbox, through the right opto board, then to the left flipper opto board. Hence both opto boards must be plugged in for them to work! If indeed one of the flipper optos is bad, and the game only has two flippers, reverse the two optos on the bad flipper opto board. One of the optos will be unused since the game only has two flippers, instead of four. Mark the bad opto, and its position on the opto board. As a general rule, the "top" opto on the flipper board (the opto farthest away from the two resistors) is the LOWER flipper opto. Unsolder both optos and move the good opto into the marked (upper) position on the flipper opto board. The only problem with doing this is a potential switch error with the bad opto. Even though the second flipper board opto is not used, many Williams games check for this switch, and will report it as "bad" in the game's power-on test report (even though the game may not use it). Also some games use the "unused" flipper opto for scrolling through the high-score initials. So ideally it is best to just replace a bad opto instead of swapping. Weak Flippers and Bad LM339's on the Fliptronics Board. If there is a marginal flipper switch reading, this causes the high powered side of the flipper to rapidly oscillate between on and off. The holding side of the flipper coil never engages. This problem will cause the flipper coil to get very hot in a short time. Opto Wavelength. Replacement Infrared LED Optos. Replacement Photo Transistors. Radio Shack also sells a combo package with both the receiver and transmitter, part# 276-142, $1.99. This is essentially the #276-143 and #276-145 parts combined into one package, at a discounted price. The word from Radio Shack is part number 276-142 will change. The the old stock LED style transmitter/receiver is discontinued, and replaced by a "U" shape style opto (though the part number is still the same). This "U" style opto will work on some unique WPC optos (see the "Radio Shack 'U' Opto" section below), but nothing else. But lately the U optos have again been replaced with separate LED style optics. Lastly, it has been reported that the Radio Shack #276-145a photo transistor is not as sensitive as the stock Williams part. Apparently if the distance is greater than two inches between the two optos, often the photo transistor will not register the infrared LED. In conclusion the #276-145a photo transmitter is not sensitive enough, since using a Radio Shack #276-143 LED and a Williams photo transmitter does seem to work at greater distances. Your mileage may vary, as Radio Shack parts can often be inconsistent. How Can I tell a Transmitter from a Receiver? WPC-95's Five Leg "U" Shaped Slot Optos. The problem with the older 4 legged flipper optos when dirty/failing was the oscillation. This would cause the flipper coils to get low amounts of power continuously during game play (like the player was pressing the flipper button on and off continuously, and very fast). This would cause the flipper coils to get hot. It would also make the flippers weak (because when the player really did press the button, the oscillation would try and turn the flippers off very quickly too!). The older 4 legged "U" optos also caused other problems on games that used the flippers to control playfield toys. For example on Indiana Jones, a dirty/failing flipper optic could cause the mini-playfield Path of Adventure (POA) to "stutter" when the player tried to move it right or left with the flipper buttons. This was a confusing error because in test mode, the POA would act normally (because the flipper buttons were not involved in the test - if the POA stutters in both game and test mode, the two 4 legged optos on the POA board could also be bad). Because of the oscillation problem, Williams changed to a five leg Schmitt trigger "U" shaped opto with WPC-95. This solved the dirty/failing optic flipper problem, and made diagnosing flipper related optic problems easier. The new five leg optos usually either work, or don't work. Replacement 5-Leg "U" Shaped Slot Optos. Replacement 4-Leg "U" Shaped Slot Optos. The industry part number for the pre-WPC95 four leg "U" shaped optos is QVE11233, with a standard sensitivity of .0110. Unfortunately, Williams requires a higher sensitivity opto for their applications. This means the cheap $1 optos from most electronic supply houses may not work, as their sensitivity rating isn't high enough. If you are shopping for these "U" optos, keep this in mind. You should be looking for part number QVE11233.0086, where .0086 is the increased sensitivity rating. This is the exact part used in Twilight Zone clocks, one of Williams most sensitive opto applications. This means a QVE11233.0086 "U" opto should work every where else just fine! As a side note, the original Williams optos were made by Motorola. But around about 1996, they split their opto electronics division into a new company called QT Optoelectronics. Then in early 2001, Fairchild bought QT. What does this all mean? Well it means the "original" Motorola brand "U" optics are all gone, but there is a fairly good stock of QT brand "U" optics around (which are identical to the original Motorola brand, differing in name only). Fairchild unfortunately has discontinued the older optic line, and no longer makes an exact duplicate of the original Motorola/QT "U" slot optos. They do make some similar optos, but the leg spacing and specs are slightly different (but they may work!) Generic "U" shaped slot optos (QT brand) with the lower .0086 sensitivity are available from Mouser (http://web.archive.org/web/20081023080129/http://www.mouser.com/, part number 512-QVE11233, $0.90) and Digikey (http://web.archive.org/web/20081023080129/http://www.digikey.com/, part number QVE11233QT-ND, $0.90). Unfortunately, these most often do not work in Williams pinball applications. A replacement "U" shaped slot opto that works 100% of the time for sure (and mounts dot on the opto to the dot on the PCB) is available from dragster_73@hotmail.com, Prestige Industries (800-456-7277 http://web.archive.org/web/20081023080129/http://www.pinball4u.com/) or Competitive Products (800-562-7283 http://web.archive.org/web/20081023080129/http://www.competitiveproducts.com/). At about $5 each (QT brand, long leads too, for the Twilight Zone clock), these are a very good replacement for nearly every Williams pinball application. The Radio Shack "U" Shaped Slot Opto. Installing the old Radio Shack "U" Optic. On the Radio Shack optos can not be found for an Indy500 fix, drill out the rivets and remove the "R" opto case from the target board. Then take a 4-legged Twilight Zone opto and pry off the case. This will expose the "guts", which can be transplanted to the Indy 500 opto board. Note the cover does NOT need to be put back on the opto.
There are two positions that a "U" shaped optic can be installed. Putting the optic in "backwards" usually does not ruin the optic, but it will prevent the optic switch from working! Many replacement optics have a "dot" or "notch" on one side of the optic. This dot/notch should align with the dot silkscreened on the circuit board (there are exceptions to this, such as the Radio Shack #276-142 "U" optic, where the optic's dot goes OPPOSITE of the board's dot, but this is a rare exception, see above). Slot optos use a dot for the collector, and a "S" for the sensor, "E" for the emitter, and unmarked is the cathode. If the new opto does not have a dot/notch, there should be "S", "E" and "+" markings on the top of the two legs of the optic. In this case, align the "S/+" leg of the opto closest to the circuit board's dot. After the new optic is installed and in the game with the power on, use the Radio Shack infrared card to find the transmitter leg of the optic. The newly installed optic should have its transmitter leg in the same relative position as the other original adjacent optic(s).
The U shaped optic's black plastic case can be reused, and just loaded with new optics "guts". Guts can be taken from other new "U" optics (that use a different style case), or the optic guts can be purchased separately. The "U" case pries apart from the bottom, using a small screw driver. The new guts are then placed inside. When doing this be careful to identify which is the transmitter *before* taking the original optic apart. This way the new transmitter and receiver can be inserted in the same positions, and the case cover installed with the "dot" in the correct location. In some applications, the black plastic case may not even need to be replaced (if there is no risk of a pinball hitting the optics, and no risk of stray ambient light). Gregg Woodcock sells these individual optic guts at http://web.archive.org/web/20081023080129/http://www.classiccoinops.com/wmsoptos.htm. The transmitter (Gregg's are red) goes into the spots marked "A" and "K". The receiver (Gregg's are clear) goes into the spots marked "C" and "E". 3i. When things don't work: Electronic Ball Sensors (Eddy Sensors and Magnetic Reed Switches)
Often eddy sensors can go out of adjustment and become less sensitive. This can cause the eddy sensor to not activate when a ball passes above it on the playfield. To adjust an eddy sensor do this: That is all that is required to adjust the STNG/ToM/RS eddy sensor. To test the sensor, put the game into WPC diagnostic's first switch test. Then move a pinball over the playfield area where the eddy sensor is located. The switch should activate on display. Also from the bottom of the playfield, the eddy board LED should go ON as a ball passes in front of the eddy board's senssor (this can be seen anytime, the game does not need to be in switch test.) Different R1 Eddy Sensor Values (Fine Tuning). The purpose of the R1 resistor is to make the adjustment pot "centered" for the particular ball sensor. For example, if you use a 2k ohm R1 eddy board in STNG, the adjustment pot will be turned almost all the way up (with very little adjustment range). It still works most of the time, just the adjustment range is not centered. With this in mind, I once had a Roadshow where I could not get the eddy board's LED to turn off, no matter where the adjustment pot was moved. Normally Roadshow uses 2k ohm R1 resistors for all three eddy boards - but in this case I had to replace the R1 resistor with a jumper wire (0 ohms). This put the adjustment pot about dead center, and the eddy boards worked great (with the 2k ohm R1 resistor, the eddy boards would not adjust, and hence would not work.)
Games made in 1996-1998 (like Sacred Stiff, Cirqus Voltaire, Monster Bash) use a second generation Eddy sensor. Instead of having a potentiometer under the playfield to adjust sensitivity, these are "auto-adjust" Eddy sensors. This style of Eddy sensor is better, as they do not go out of adjustment. But they also use more logic parts, meaning more electronic parts to potentially fail. You can buy replacements for these boards at PinBits. The new auto-adjust boards are plug compatible with the older manual adjust eddy boards (generally speaking), but some resistor values may need to be changed (again R1). Twilight Zone Eddy Sensors. Another common TZ problem are the molex connectors on the driver board. Just taking the two pin molex connector off and putting it back on its header pins will temporarily remedy the problem, but the issue will return. The .100" molex connector pins need to be replaced inside the plastic connector housing. Or the wires can be soldered directly to the .100 male pins. This obviously is not ideal, but it does solve the problem, as the pins in the connector cable lose their grip over time. Also this small board often needs to have its male .100" molex header pins resoldered. The solder joints on the board's header pins can crack. It is possible for the TDA0161 (Williams part number 5370-13452-00) chip to die on this board. If you don't want to replace just this chip, the whole proximity driver board is available from Marco. Modifying your Twilight Zone Eddy Sensor. The modification is now done. Install the sensor board and the cable that goes between it and the driver board. With the sensor board installed, the pot should be easily accessible with a small screwdriver. Now power on the game. With NO balls in the ball trough, adjust the installed pot just as described above (for the newer Eddy sensors): Magnetic Reed Switches (beyond Eddy sensors). Instead, Williams changed to a Magnetic Reed Switch (MRS) with Safecracker and NBA Fastbreak. This style of switch is contained in a black epoxy package, about 2" long, and 1/2" wide. Like an Eddy sensor, it can sense when a pinball is near the switch. Games which used this reed switch include NBA Fastbreak, Safecracker No Good Goofers, Cirqus Voltaire, Cactus Canyon and Star Wars Episode I. I believe these are the only games that used the reed switch.
3j. When things don't work: Ball Trough Problems (random multi-ball and bad trough LEDs)
Starting in 1993 with Indiana Jones, a new ball trough design was used that instead relied on gravity to feed the balls into the trough. This saved one coil (the outhole coil was no longer needed). The new design also used opto switches instead of mechanical switches. This allowed one ball trough design to be used in all Williams games, regardless of the number of balls used in the game. The ball trough could now comfortably hold from one to six balls (depending on the game; most used four to six balls).
When the opto ball trough was first used on Indiana Jones, Star Trek Next Generation, Judge Dredd, Popeye, and Demoman, William bolted the opto boards right to the side of the trough. The vibrations from the trough often caused the leads on the large blue two watt resistors and the infra-red LED's on the opto transmitter board to break. This would cause the game to start random multi-ball at just about anytime during the game. Often the game would never end (because the trough would not reconize when all the balls had drained). To fix this problem, Williams redesigned the attachment points for the two opto boards. Instead of being bolted directly to the trough, the mounting holes on the opto boards were enlarged (and one hole moved). Then rubber gromets where inserted into the holes, and short metal tube bushings where inserted through the rubber gromets. When the opto board bolts where tightened down, they tightened on the metal tubes. This allowed the opto boards to "float" on the rubber gromet, reducing vibration considerably. Also be aware that on Star Trek Next Generation if fuse 103 on the Power Driver Board is blown (3A slow blow), the game will not start and will constantly throw out balls. Fuse 103 powers the solenoid which controls the upper diverter on the under-the-playfield diverter. Without a working diverter, the game can't load the balls where it wants, and the game will attempt to load and reload balls continually. Also another tip concerning Indiana Jones: Check the front right switch on the bottom side of the mini playfield. Balls hit it underneath and mash the wires/diode/switch lugs together creating a short. Since this mini-PF switch is in the same row as the ball trough jam opto in the switch matrix. This can cause the game to continually kick out balls because the machine thinks the ball jam opto has a ball in front of it, and kicks out another.
To make the opto boards more resistant to vibration, starting with World Cup Soccer 94, Williams moved all the electronics off the opto boards and onto a separate board. This meant that only the optics were on the trough opto boards, and no other components. No longer could the large blue two watt resistors crack from trough vibrations. Unfortunately, Indy Jones, Star Trek Next Generation, Judge Dredd, Popeye and Demoman all use the older ball trough opto boards with the easy-to-break blue resistors and bad mounting design. Check the Shooter Lane switch. Ball Trough Divots (Indy Jones to Cactus Canyon). At first look, where the balls fall from the playfield into the trough would seem to be the problem. But that really is not the big problem; where the balls rest in the trough "V" slot can develop very small divots or nicks in the metal. All these newer game use four to six balls, and often a pair of nicks in the metal can exist where each ball rests in the trough! To fix this, a Dremel tool or a hand file can be used to grind the divots out of the metal. After the nicks are ground out smoothly, sand the sides of the "V" in the trough smooth with 220 or 320 sandpaper. If this doesn't work, order a new ball trough, part number A-16809-2. This newer design of the ball trough should last longer and divot less.
If you want to upgrade your Indiana Jones to Demo Man ball trough to the current board mounting design (which can help solve random multi-ball problems), order an upgrade kit, part# A-18244. This includes two new opto boards, and all the mounting hardware needed (the mounting hardware is absolutely necessary). At $50, this is an expensive kit! Modifying the Existing Trough Boards Mounting Instead. These parts can be bought locally. Rubber grommets can be bought at any decent hardware store in the electrical department. The inside diameter grommet hole (the important part) is 3/16". The outside diameter can vary from 1/4" to 7/16". The metal 3/16" bushings can be bought at hobby shop that sells 3/16" brass or aluminum tubing (usally in 12" lengths), used for hobby applications. This tubing cuts easily with a Dremel cut-off tool, or for $5, most hobby shops also sell small tubing cutters (easier to use than the Dremel). Buy metal tubing which fits easily but snuggly inside the 3/16" rubber grommet (3/16" or even 5/32" outside diameter tubing). The longer 3/4" #6 trough board mounting screws are also required, and are a standard hardware store item.
More Random Multiball: the Ball Trough Optic Resistors. Do not try and repair the resistors; just replace them. They are 270 ohm 2 watt resistors (do not replace with a version less than 2 watts). These are available from Digikey, part number ALSR3J-270-ND, $1.37 each. NTE/ECG sell these too at many local electronic part houses for about 99 cents a pair. Ball Trough Optos. The receiver optic is also available from Radio Shack, part number 276-145a, $0.99. This receiver is clear, unlike the Williams receiver. The flat edge of the receiver needs to be mounted closest to the top edge of the circuit board. That is, the flat edge goes in the hole furthest away from the hole that has the notch drawn on the circuit board. Digikey also sells a receiver, part number PN104-ND. When installing this photo transistor remove the center pin before installing. Just wiggled the center lead back and forth until it breaks off at the base. Install this part so the notch at the base lines up with the notch drawn on the circuit board. The New Williams Ball Trough and the Blue Resistors. Bad Ball Trough Connectors. Testing the Ball Trough Optos. After that is done, shine a small pocket flashlight or TV remote control into each of the receiver board detector optos. They should register in the T.1 switch test (room needs to be somewhat dim for this; ambient room light can also activate these). Turn the game off and assembly and install the trough board on the trough, and install the trough back in the game. Now it's time for another test, one that is especially good to verify your work, or to test the trough if you have not modified it. With all the balls removed from the game, turn the game on and go to the first switch edge test T.1. Most switches should show with a dot, indicating the switch as open (a sqaure indicates a switch is closed). But on optic switches, a blocked opto is a dot, and an unblocked opto is a square (opposite of what one would expect). There should be a number of squared switches, indicating the opto trough switches (check your game manual for exact switch numbers). If your switch matrix has no squares (all dots), your playfield has lost the +12 volts powering the optic switches. Check fuses F115 and F116 (F101 and F109 on WPC-95) on the power driver board. Now slowly roll a ball down the trough and watch it cause a square in the switch matrix to turn into a dot, as the ball rolls past each ball trough optic. When the ball is resting at ball trough optic one, physically push up on the ball lane shooter solenoid (that would kick that ball onto the playfield). This will cause that "trough jam" opto to turn to a dot. This opto only sees the ball as it gets kicked out, or if there are two balls jammed so they are sitting on top of each other at the right end of the trough. Fill up the trough completely with balls, then remove the balls manually, one by one. Try this a few times to see if you can isolate any of the ball trough squares which are not turning to dots consistently. Lastly, remove ALL balls from the trough and close the coin door. Press the flipper buttons to activate the flippers while still in switch edges test. Look for flickering square-to-dots on the ball trough column on the display. This tests flipper vibrations which can cause intermittent flickering on the opto switches. Now continue checking for bad optos by hitting the playfield with the meat of your fist near the flippers (it's not as bad as it sounds!) If any of the squares flicker to a dot, there is some vibration related problem (broken/cracked blue resistor or opto lead, or cracked header pin solder joints). If nothing has appears, leave the game in this test mode for 20 minutes (note some games will exit test mode automatically after 15 minutes) with no balls in the game. Be close by, within listening distance. If you hear the game "bong" that means a switch has opened/closed in the switch test. Go to the game and check the score display, as the last switch closed will be reported. See if this is a trough opto switch number. If so, it is a flakey opto or bad opto board resistor or bad connector. This "time test" allows the game to 'warm up' too, which often the other tests don't account for. If all the trough switches change from squares to dots when the optos are blocked with a ball, and there is no flickering when the playfield is vibrated, and the game doesn't report any random switches in test mode for 20 minutes, the opto boards have test good. If there are still random multi ball problems, there is most likely a divot problem in the ball trough (see above).
The ball trough transmitter board needs +12 volts DC to operate, and nothing more. Because of this, the ball trough transmitter board can be tested outside of the game using an external 12 volt DC power supply. Also needed is some way to "see" the infrared light coming from the transmitter LEDs. A digital camera with a viewing screen works well, or a Radio Shack/MCM Electronics infrared card. 3k. When things don't work: Dot Matrix/AlphaNumeric Score Displays
WPC Alpha Numeric Score Display Problems.
The unfortunate part about dot matrix displays (DMD) is they wear out. Time will eventually kill these, and the display will "outgas" and fail. Because of the high voltage involved with score displays, the anode and/or cathode inside the diplay glass breaks down. This results in the "outgassing" of impurities that eventually change the internal gas properties, so the display won't glow (the gas must be very pure for the display to work). Often the gaps that don't light up at power-on will gradually come on as the display warms up. This happens because as the existing gas warms up, it expands. A new display will solve this problem, and is easy to get and replace (a 5 minute job). These do cost a bit of money though at about $115 each (complete). There is no way to fix an old "outgassed" display. When a DMD starts to get blurry or displays gaps, the rumor is the power requirements for the display increases. It turns out this rumor is actually incorrect, at least as far as the High Voltage (-120 and +65 volts) is concerned. The HV (high voltage) power used by a display is directly proportional to the number of dots lit on the display. If a display is entirely outgassed and not lighting (even though the CPU is asking the display to lit), it will consume no more HV (high voltage) than a working display that is not lit. Kirb did some test of various displays and metered the results, proving this. But what about the 5 volt consumption? Unfortunately we did not do enough testing of the 5 volts to draw any conclusions. But based on reports of outgassed displays causing game resets (stressing the 5 volt supply), it is reasonable to think that an outgassed DMD does consume more 5 volt power. Another interesting fact is that certain DMD makes consume more 5 volt power than others. The biggest 5 volt power hog is Dale/Visay, consuming nearly twice what other DMD displays use. Regardless, I still encourage people to buy a new display if theirs is outgassed. The 5 volt power stress, particularly on games like Twilight Zone, can cause potential game reset problems. Buy an entire DMD display glass and board, or just a new
Glass? Are All Dot Matrix Displays the Same? Can the Dot Matrix Display Itself be Fixed?
(Re-seating Ribbon Cable connectors, RAM errors). This problem can be caused by a bad dot matrix ribbon cable. A blank display (assuming all the fuses are good and voltages are present) is usually a backwards installed ribbon cable from the dot matrix controller to the DMD itself. Garbage or diagonal lines is typically a problem with the large cable running from the CPU board to the fliptronics board to the sound board to the dot matrix controller board. The ribbon cable connectors are gold plated, and sometimes require a "reseating" (remove and re-install) of their connectors to "clean" them. Since these are gold plated connectors, reseating is an acceptable means of cleaning a gold plated connector. (All the non-ribbon cable connectors in the game are *not* gold, and if reseating "fixes" a problem, that means the connector board pins and housing pins need to be replaced! See Pinball Connector web page for more info on that.)
Also note the red line on the ribbon cable - this indicates pin 1 of the cable, and it should align with the white arrow or "1 2" silkscreened on the circuit board. Luckily the only ribbon cable connector that can be easily installed "backwards" is the ribbon going from the dot matrix controller board to the display. If this cable is installed "backwards", usually the display is blank, showing nothing (like the display does not work).
Is there still strange behavior on the display? Maybe happens just sometimes, but not all the time? Do a diagnostic RAM test on the display. Enter the WPC diagnostics through the coin door switch, and go to Tests "Display" (often test T.11). This will do a RAM test. If any "Page Errors" or "Data Errors" are seen, the RAM chip on the Dot Matrix Control board will need to be replaced. This diagnostic test should come up with absolutely no errors. Alternatively the whole Dot Matrix Controller board can be replaced (these are available for less than $100 brand new.) Finally, random vertical or diagnal lines could be caused by 12 volts not getting to the dot matrix display. This voltage comes directly from the driver board (see "Testing DMD voltages" below for diagnosing this problem further). Also some dot matrix displays (Babcock in particular) require 12 volts to operate, where other brands do not need 12 volts. Missing Vertical or Horizontal Display Lines are Missing. If missing some lines, and the score display glass is a "pin" style, often the pins can be reattached to the display glass using a conductive silver epoxy. This often works well, but is a difficult repair. It usually does not work if more than two horizontal and/or two vertical pins are broken. Diagnosing Other Dot Matrix Problems. Make sure to check fuses F601 and F602 (all WPC games). F601 is used for +62 volts, and F602 is used for -113, -125 volts (or -103, -115). On WPC-S and before, these are 3/8 amp fast-blo 1.25" fuses (originally Williams used slow-blo fuses here, but about 1994 they changed to fast-blo, so either fast or slow-blo can be used). On WPC-95, these are T0.315 amp 5x20mm fuses. The Dot Matrix Display circuit is the same in all WPC
generations!
If the fuses are good on the dot matrix controller board (or audio/visual board for WPC-95), you should next check the power at the DMD itself. Voltages used are +62, +12, +5, -113 and -125 (or -103 and -115), or within +/- 10% of these values. Check these voltages at the dot matrix display with the display connected, or at connector J604 on the controller board. The pin out at the DMD is: If any voltage is low, try disconnecting the power connector to the DMD, and re-measure the voltages. If they return to the correct voltages, the display is bad or the high voltage section on the dot matrix controller board is failing and can't handle the power draw of the display. Remember the voltages created by the DMD controller card are -125, -113 (or -115, -103) and +62. The +5 and +12 volts come from the driver board. If the 5 volts is missing yet the game boots, there's a connector problem. If 12 volts is missing there's either a connector problem, or the dot matrix display itself is "sinking" the 12 volts (disconnect the DMD power connector and see if the 12 volts comes back up, if so the display is bad or maybe the driver board 12 volt section is failing). Or the 12 volt driver board section is failing. (Measure the 12 volts at the driver board, and then at the installed DMD, if the voltage is different there is a connector problem. If they are both the same voltage and are below 10 volts, there is a driver board 12 volt problem). Lowering the -125 and -113 voltages to -115 and -103
volts. Both the -125 and the -113 volts are the same voltage. The +62 volts drops to +12 volts under load. The +62 volts is not +62 volts. The -125 volts is too High. Negative High Voltage Low, DMD barely lights. Rebuilding the Dot Matrix High Voltage (HV) Section. After all else is checked, the best idea is to just replace everything in the high voltage section (parts also listed at dmdhv.htm). Note all these parts are also available in kit form from Great Plains Electronics for around $6 per kit. This is a *very* economical way to rebuild the dot matrix high voltage section. The parts to replace includes: Check/Replace the Resistors too. An Alternative to Rebuilding the HV Section. I have some minor critisms with the DMD HV board though. For example, they use the smaller WPC-95 style fuses. Now this would be Ok if the board worked on WPC-95 games. But since it does not, it puts a mix of fuse sizes into a WPC game that otherwise don't use this smaller fuse size. This is bad for the end consumer that may have a supply of stock WPC HV fuses, which now won't work in their game! Also, I feel there should be LEDs for each of the high voltages to show at a glace that -125 volts, -113 volts, +62 volts (and perhaps the +12 volts and +5 volts) were working on the board. DMD Components by Voltage. The BIGGEST Tip when Fixing the High Voltage.
Cloudy display problems are strange. The display can test perfectly in the internal "line" dot matrix test. But when large areas or inverted graphics are shown, the display is "cloudy". This is usually caused by heat related problems. Fixing this could be as simple as adding new white heat sink compound to the three heat sinked MJE transistors. Also make sure they are tight to their heat sink. Check the three large 5 watt resistors too. If they are more than 5% out of spec, replace them (see above). Lastly, cold solder joints in the high voltage section can also cause cloudiness. Try reflowing the solder joints on the 5 watt resistors, the high voltage diodes, and the high voltage MJE transistors. If none of this works, rebuilding the high voltage section should solve this problem (see above). Wavy Hum-bar, bounce, or Horizontal Roll on the Dot Matrix
Display. Additionally, if there is still a "wavy hum-bar" or horizontal roll or a display "bounce", try replacing the smaller high voltage filter capacitors. On WPC-S and earlier, these are capacitors C6, C9 and C10 (.1 mfd 500 volts) on the dot matrix controller board. On WPC-95, these are caps C29-C31 (.01 mfd 200 volts). If these caps fail, hum bars or roll can occur. As the game warms up the wave, roll or bounce may change (get better or worse). Crystallized Solder Joints.
If there is a column or two stuck on (as seen in the picture above), chances are good the 6264 dot matrix controller card RAM at U24 (WPC-S and prior) has failed. Of course this assumes that the dot matrix display itself is not the problem (try the display in another game to verify). If not the display itself, replace U24 (WPC-S and prior) with a new 6264 RAM chip, and this should fix the problem. Missing Lines on a DMD Display. On displays with broken pins, there isn't enough material to solder the pins back to the display glass. But another technique can be used instead. This involves "conductive epoxy", and essentially gluing the broken pin to the score glass. The conductive epoxy has silver powder in it, so it conducts well. And it's the only way to get a broken pin attached back to the score glass. Usually one or two broken pins can be repaired in this manner (trying to do much more than three seems to not work well!) Just be careful not to short two pins together with the epoxy. Success rate is certainly not 100%, but it usually works. The epoxy is expensive though, because of the silver powder in the glue. I have also used conductive epoxy to fix the thin ribbon cable variety of DMD displays with missing lines, where the ribbon cable has ripped away from the display glass. The success rate is not as high, but it can work.
Answer: the ASIC chip on the CPU board was not making good contact to its socket. The ASIC chip is the large square chip on the CPU board. After removing the chip and cleaning all of its pins, and reseating the chip in the socket, the problem went away. Another thing to try is reseating the board ribbon cables in their sockets. Problem: Funhouse alphanumeric display, character 16 was mimicking every segment being displayed in the other 15 characters. Answer: If this is happening in display one, replace chip U8 (6184 Anode Drive) on the WPC display driver board. If happening to display two, replace chip U5 (6184). Problem: My Twilight Zone's dot matrix display shows random vertical lines. At first it was just occassionally during game play, but now they appear from the moment I power on the game. The problem has gotten worse, and now every time I turn on the machine, all four flippers energize. Answer: the problem was a bad ribbon cable. There is a single ribbon cable that goes from the CPU board to the fliptronics board to the sound board to the dot matrix controller. If the ribbon cable was mis-installed by one pin, or the cable has torn at its connector, this problem can happen. The ribbon cable houses the address and data lines to the fliptronics, sound and dot matrix controller. Often the ribbon cable's connectors can just be dirty, so reseating the connectors sometimes fixes this problem. If the ribbon cable is damaged, mis-installed or the connectors are dirty, strange things like this can happen. Another potential cause could be the lack of 12 volts getting to the dot matrix display controller board.
3L. When things don't work: Power-On LEDs and Sound Beeps
A simple diagnostic LED (Light Emitting Diode) flash pattern exists on all generations of WPC CPU boards. These flashes can signify a problem and what might be causing the trouble. They can be seen immediately when powering on the game. LED's exist on both the CPU and Driver boards, but only the CPU board's LED have a diagnostic flash pattern. On WPC-S and earlier CPU boards, the LED's are labeled D19 to D21. On the driver board and all WPC-95 boards, they are labeled "LEDx" (with "x" being the LED number). CPU Board LED Flash Codes, all revisions. WPC-S and Prior Driver Board LEDs, Test Points (TP), and
Fuses. WPC-95 Driver Board LEDs, Test Points (TP), and Fuses. Sound Board Error Beeps pre WPC-DCS (WPC alpha-numeric, WPC dot-matrix and WPC fliptronics. Sound Board Error Beeps WPC-DCS and WPC-S. WPC-95 Audio/Video LED. 3m. When things don't work: "Factory Settings Restored" Error (Battery Problems)
Most often, this error occurs because the three "AA" batteries on the CPU board have died. These batteries should be replaced every year with good quality alkaline batteries (batteries are cheap, battery damage is expensive). The three batteries must keep at least +4 volts of power to the U8 RAM chip for it to remember. When power goes below +4 volts, memory reset can occur (and you get the "Factory Settings Restored" error message).
If your game is working, and it's time to replace the batteries, follow this procedure: If you install new batteries with the game turned on, the machine will not forget the old option settings or bookkeeping totals. More on Installing Batteries and Measuring their Voltage. The next test for voltage on the WPC CPU board's RAM chip. The last pin of the RAM should show at least 4 volts DC. Test this with the game off and the black DMM lead on ground, red DMM lead on U8 pin 28. If battery power is not getting to the RAM, then either the battery holder is bad or the blocking diodes are bad. The blocking diode D2 (1n914 or 1n4148) can be tested with a DMM set to diode test (game off). Black DMM lead on the banded side should show .4 to .6 volts. The Battery Holder: a Weak Link.
Remote Battery Holder. I personally use a four "AA" battery holder, using the fourth battery cell area for a back-up blocking diode and as the screw area (to do this I put a 1N4004 or 1N5817 diode with the band towards the red wire, where the fourth battery would be located). The four AA battery packs seem to be easier and cheaper to find, but of course only use three batteries! Install three "AA" batteries, and then solder the red positive wire of the remote holder to the CPU board's main positive battery holder trace, and the black lead of the remote holder to the CPU board's opposite main negative battery holder trace (see pictures below for installation in WPC-89, WPC-S, and WPC-95). On WPC-89 and WPC-95, the main positive battery terminal is at the upper right of the original battery holder, and the main negative terminal is at the lower left. On WPC-S the main positive battery terminal is at the lower right, and the main negative at the upper left. Some people ask why I put the "blocking diode" in my 4 "AA" battery holder? Well it is not required, but I put the blocking diode in as a backup diode (which prevents the CPU board from trying to charge the AA batteries when the game is on). The other advantage to this is the added blocking diode slightly decreases the voltage from the batteries. This is like an advance alarm clock for me, where the game will tell me when the batteries are getting low (opposed to them totally dying and leaking, and then I find out I need to replace them!) Using a common 1N4004 diode will give the most voltage drop (about .4 volt). This decreases the battery voltage just enough that the game will give me a "factory settings restored" error just before the batteries are totally dead - which is exactly what I want!
If the battery holder is OK, next check to see if power it getting past the battery holder. Find CPU board diode D2 (all WPC revisions); this is a small glass diode, right next to diode D1. On WPC-S and prior, look to the right of the big square chip U9. On WPC-95, look just below the battery holder. With your game off and new batteries installed, put your DDM on DC volts and put the black lead on the backbox ground strap. Then put the red lead on diode D2 on the CPU board. The banded side of the diode should show about .5 volts less than the non-banded side (which should be about 4.3 volts). If only one side of the diode shows voltage, or both sides show the same voltage, this diode is bad. Diode D2 is a 1N4148 or 1N914 diode. Next test for voltage at the CPU U8 RAM chip (all WPC revisions). With the game off, you should get about 4.3 volts DC at pins 26, 27 or 28 of chip U8. If you don't, the battery voltage is not getting to the U8 RAM chip, and the game will boot up with the "Factory Settings Restored" error. Note pin 28 of the 28 pin U8 chip is in the same position as pin 1 of the chip, but on the opposite row of pins. Pin 1 is designated with an impressed "dot" right on the top of the chip. There can still be problems even if a new batteries are installed and all the voltages check out. If the game is still giving "Factory Setting Restored" or "Set Time and Date" errors, there may be a bad CPU U8 RAM chip. This does happen where a bad U8 RAM will suck the life out of new batteries, causing them to go dead in one to four weeks. But make sure to double check that battery holder. Even minor corrosion can cause this problem. The voltages may all check out, but the corrosion may be enough to limit CURRENT, and cause this problem. The U8 RAM chip is a 6264-L or 2064 RAM chip. Batteries Die Too Quick. Also check and test diode D2. With your game off and new batteries installed, put your DDM on DC volts and put the black lead on the backbox ground strap. Then put the red lead on diode D2 on the CPU board. The banded side of the diode should show about .5 volts less than the non-banded side (which should be about 4.3 volts). If only one side of the diode shows voltage, or both sides show the same voltage, this diode is bad. Diode D2 is a 1N4148 or 1N914 diode. Batteries are HOT! Does the Battery Power Anything Else?
There is an internal time clock that keeps the time and date for the WPC system. Within the game's adjustments, you can turn the clock display on, so it shows the time and date on the dot matrix display. On Twilight Zone, this internal time clock is used during attack mode to set the playfield clock. If you notice the WPC time clock running slow (losing time), or the game just won't remember the time (boot up error of "Set Time and Date"), the batteries are getting weak and need replaced. If you still have this problem with new batteries, suspect the battery holder's terminals. They may be corroded enough to cause resistance, and lower the voltage at CPU chip U8. 3n. When things don't work: Lightning Strikes
3o. When things don't work: Sound Problems.
The Pre-DCS A-12738 Sound Board. Line-Out. Unfortunately a bit more needs to be done then just tapping into connector J509 to get a usable "line out". On pre-DCS games on the component side of the sound board, lift resistor R102 on the side which connects to pin 3 of J509. On the back of the sound board, connect a jumper wire between the negative side of capacitor C21 and the plated-thru hole left of resistor R102 (which connects to pin 1 of J509). This will give a functional line-out at J509 with the pins indicated above. The line-out you get from this modification is a fixed level and does not get changed by the volume control. To get a line-out on a WPC DCS game (pre-WPC95), add a two pin .156" molex header to the sound board connector J6 (the left pin is audio and right pin is ground). On WPC-95, just add a two pin header to sound board connector J509 (left pin is ground and right pin is audio). Note the line-out on DCS and WPC95 sound boards is directly controlled by the volume control buttons inside the coin door. Volume Control. General Sound Repair Tips.
Volume up FULL and Can't turn it Down. Static Noise and Loud Whistle. Another problem I saw on a WPC DCS sound board was a really high pitch whistle as soon as the game was powered on (in this case Jackbot). The volume control did not the whitle volume, and the game play sound could be heard behind the whistle. The whistle was so loud and obnoxious it was difficult to have the game powered on for more than a few seconds. First thing done was to isolate the CPU from the amplifier section. This was done by removing the ribbon cable from the sound board, and by removing the sound EPROM. This way the sound board could not execute any code, and the CPU was basically detached from the amplifier. The whistle contined, indicating the problem was not in the processing of the sound, but in the sound amplification. Looking at the schematics showed that the only things really not involved in computer processing of sound is the pair of TL084 Op-Amp chips and the TDA2030A ampifiers. In this case it was a bad TL084 causing the problem. Static/Minor Hum and the Sound Board Filter Caps. Static & Scratchy/Tinny Sound on Early WPC-95 Games. Intermittent Sound Cuts and Shrieks. TDA2030A Amp Chip. Loud Hum from the Speakers. "Popping" Sound, Hot LM1875, and Speakers Shorting. Replacement Speakers. The most common speaker to die on a WPC game is the backbox tweeter (right speaker, as playing the game). This is a small 3.5" speaker with a capacitor attached to the negative speaker terminal (the capacitor is the "cross-over", which filters out all but high frequency sounds). A quick and dirty replacement tweeter is available from Radio Shack, part #40-1233, $9.95. Though this is a 3.75" tweeter, the holes can be enlongated slightly to fit the 3.5" bolt pattern. The 6" speaker in the bottom of the cabinet can be replaced with a PinballPro subwoofer. See http://web.archive.org/web/20081023080129/http://www.decoratorsupply.com/pinball/speakers.htm for details. They also sell replacement speakers for the backbox. Sound Board Interface Error and Sound ROM Checksum
Problems. First thing to try is reseating all the ribbon cable connectors. Past this, usually the problem is a bad sound ROM. If the error is still present, turn the game off and remove ALL the sound ROMs from the sound board. Turn the game on, and instead of the one power-on "bong", you should hear two "bongs". Turn the game off, and replace the first sound ROM (U9, U2, or S2, depending on the WPC generation). Turn the game back on, and three "bongs" should be heard. Keep adding ROMs one at a time. If there is a problem with one of the sound ROMs, a checksum or soundboard interface error message will be displayed when the problem ROM has just been installed. If this happens, replace the ROM in question. Blown Sound Board Fuse. I Accidentally Shorted -125 volts on the AV board, and now my
WPC-95 game will not Turn on. In this case, do the easy things first. With the game off, remove all the EPROMs from the sound board. Then try your game again. The game will complain with a "bong bong", signifying a sound board ROM problem. But if the game turns on fine otherwise, you know one of the sound EPROMs is bad. Unbalanced Speech and Music.
R# Schem. Funhouse Addams R25 150k 120k 120k R24 120k 150k 56k R23 120k 150k 56k R22 150k 120k 120kSo, at least for these two machines, Williams has changed the resistor value to change the balance between speech/sound effects and music. On Funhouse they have biased the sound toward speech, and on Addams towards music. This means that WPC audio boards are not quite as interchangable between machines as thought, although they work, both Addams and Funhouse sound very different. 3p. When things don't work: General Illumination (GI) Problems.
The Single Biggest Problem with WPC General Illumination. It is really simple to check. Just use a DMM set to "buzz" (low ohms), and check the continuity from the header pins, to the fuse holder, and to the triacs. You will need the schematics to verify the pin numbers, fuse numbers and triacs. But if the GI is not working, it's pretty much a for sure the problem is a broken circuit board trace (specifically it's usually a broken plated-thru hole on one of the .156" GI header pins). CPU Control of WPC General Illumination. Triacs are used for the general illumination circuit (not needed very often). The specs for a WPC triac are pretty lose. For example all these work: BT138-600E, BTA12-600, NTE5671 (800v 16amp), NTE56010 (800v 15amp), or NTE56008 (600v 15amp). GI String(s) do not Dim. Triacs. With the game turned on using a voltmeter on AC, connect the ground side of the meter to the ground. Now touch the red lead to the "tab" screw on each of the Triac heatsinks. There should be around 1 volt AC (or a little less) on each of the tabs if all the G.I. lights are on. This is an indicator the Triac is working correctly. Also feel each heat sink and see if it's warm or not. If one feels somewhat cold, it's probably not "turned on" and is the culprit you will want to investigate further (but in my experience the traiac itself is never the problem - it's usually the input connector J115, the fuse, or a broken board trace). A Triac is like a switch. It has one input pin, one output pin, and a "gate" that causes the input to be routed to the output when the gate goes high. When the lights are to be turned on, U1 (74LS374) supplies a low that turns on the PNP Triac driver transistor, which causes the PNP Collector to approach 5 volts. This 5 volts is connected to the Triac "gate", which turns on the Triac. When this gate goes high, the J115 AC voltage (the low side of the secondary AC) of the Triac is routed to the other pin of the Triac, which completes the circuit for the light bulbs to turn on. The game can turn the Triacs on and off many many times per second, giving them a "duty cycle". This is how a G.I. string can be dimmed (more "off" time between "on" cycles, and the G.I. string looks dimmer).
If the GI light still do not dim, replace the Driver board's zero cross circuit LM339 chip at U6 (or U1 on WPC-95). This will usually fix the problem (assuming there are no broken driver board traces, as shown above). It could also be the 74LS374 at U1 (or U2 on WPC-95). Note if only one GI string does not dim, the LM339 is probably not the problem (start with the Triac). GI String Refuses to Work (and it's not the Driver board
connector).
The driver board Triacs are the devices that allow the GI strings to be dimmed. I've never had to replace one, but here's how to test a Traic. First a Triac is basically a bipolar (meaning it can be used for AC voltage) SCR (Silicon Controlled Rectifier). A SCR has a Cathode (often labeled "K"), Anode, and Gate (instead of a Base, Collector and Emitter like a transistor). A Triac also has three connections, but are labeled Gate, "Main Terminal 1" (MT1), "Main Terminal 2" (MT2). In this case, the "Main Terminal 1" is the Cathode. "Main Terminal 2" is the Anode, and the Gate is the Gate. The normal "diode test" on your DMM just won't work for testing a Triac (or a SCR), because of the device's need to be triggered first. All you can tell from the DMM's diode test is if the Triac is shorted, but nothing else. Because of this, to test a Traic, you will need some sort of power. The best way to do this is using a 9 volt battery. Here's how you hook up your battery, and a test 555 or #44 light bulb (note this will probably have to be done with the triac removed from the board). Since a Triac is bipolor (used for AC applications), reverse the battery's polarity and repeat the above test. It should work the same. Shorts in the General Illumination (Blown GI Fuses).
If voltage is seen then the driver board is OK, and there is a short on the playfield or backbox wiring. Common causes of shorted strings include solder drips on or in a lamp sockets, metal objects in a lamp socket, chaffed wires touching ground, socket terminals touching another wire or metal, a shorted socket, or even a shorted bulb (this is why I like to replace GI bulbs one at a time with the power on). With the game off, use a DMM and test either of the two GI power wires for continuity to ground (it doesn't matter which wire is tested as there is continuity between the two GI wires if even one light bulb is installed in the GI string). If the wire is grounded, examine the wire run for chaffing or a socket terminal touching metal ground. If neither wire is grounded, remove all the bulbs from the string and check continuity to ground across each of the two GI wires, and check for continity between the two GI wires. If there is continuity between the two GI feed wires, there is either still a bulb installed in the string or there is a short (probably in one of the lamp sockets). If no continuity, then reconnect the connector and begin testing bulbs. A shorted bulb will not blow the fuse or cause all the GI bulbs to dim noticeably. If the string was indicating a short with all bulbs removed, then inspect each socket carefully -- inside and out. Another trick is to incrementally disconnect one of the feed wires along the chain to isolate sections and localize the short to a smaller area. This process will be tedious but sometimes it's the only means to find the problem. Another neat trick is to take a blown fuses and solder wires from the ends of the blown fuse to a light socket. Then put a good #44 or #47 bulb in the socket. Be sure to solder the wires so that they will still allow the fuse to go back in the fuse holder. Now plug the blown fuse/socket into the fuse holder which controls the GI string in question. If all the GI bulbs are removed from this GI string, the lamp attached to the blown fuse should be off. If the lamp is on (and all the GI bulbs are removed), you have a short in the GI string somewhere. You can leave the game on and wiggle wires and exam the blown fuse/socket to see if the lamp goes off. This will help locate the short without going through lots of fuses in the process. 3q. When things don't work: Test Report & The Diagnostic Dot, Strange Game Behavior.
Most test reports refer to switches that are tagged as defective. Often this is not the case. If a switch hasn't be used in 30 games, it will be listed as bad. But it could be the switch is working, yet positioned in a place that it just doesn't get activated much during game play. If you do get a test report about a possibly defective switch, go to the "switch edge" test and manually activate the switch. This will indicate if the switch is working. If it does work, this will reset the 30 game counter for this switch and the switch will not be reported in the test report. Prototype ROM Software and Bad Switches. The Diagnostic Credit Dot.
Strange Game Behavior. Sometimes strange game behaviors can be seen that results from ribbon cable problems. For example, a series of veritcal lines in the dot matrix display. Or a coil or lights that do not work. Or at power-on more than one beep is heard from the sound board (signaling a sound board problem). Often just a simple re-seating of the ribbon cables will fix this. WARNING: be careful when reseating ribbon cables. They can be easily damaged where they connect to the plastic connectors. The ribbon cable damaged the most if the cable with the four connectors that attaches to the CPU, fliptronics, sound and dot matrix display controller. An open wire in the ribbon cable can cause a lost data bit, resulting in wacky sound and dot matrix display data. This can cause vertical lines in the dot matrix display or game sounds are wrong. Often the problem is the ribbon cable that links the sound and display controller together fail because they get old and brittle in the hot backbox. 3r. When things don't work: Fixing a Dead or Non-Booting CPU board.
It doesn't happen often on WPC games. You have power (+5 and +12 volts) getting to the CPU board. The +5 LED (lower of the three) is on, as it should be. But the middle diagnostic LED is not flashing constantly (indicating the CPU is dead). And the blanking LED (the top one) is doing nothing (no flashes when the game is turned on). You have a dead CPU. CPU Flash Codes, all revisions. D21/LED202 should *always* be on, as this indicated there is +5 volts at the CPU board. The board will never run without +5 volts! Problem Power-On CPU D20/LED203 (diagnostic) Flash Codes. Some Basic Info on the WPC CPU Board. Dead CPU Step Zero: Check the ROM jumper setting. Dead CPU Step One: Remove the Ribbon Cables. After everything is removed but connector J210, turn the game on. If the CPU board boots correctly, the lower LED (+5 volts) should be on, the middle LED (diagnostics) should be blinking continually, and the top LED (blanking) should be off. If this is the case, turn the game off and replace the ribbon cables, one at a time, and turn the game back on. Start with replacing the the driver board to CPU board ribbon cable first. Chances are good the CPU board will still boot with this cable connected. Next try the other ribbon cables. If connecting the other ribbon cables stops the CPU board from booting, chances are good the TTL chips across the top of the CPU board are the problem (U1,U2,U3 on all WPC revisions). Move to the Work Bench.
With the CPU on the workbench and issolated from the game, you can test the board much easier. Re-seat the U9 ASIC WPC chip.
As power is applied to the CPU board on the bench, a working CPU board will behave the same as in the game: All three LEDs briefly flash on, then the top LED turns off (while the bottom LED stays lit this whole time), and then the middle LED starting pulsing rapidly on and off. If that's what happens, then the board is "booting" and running. Booting and running means the top LED is off, the middle is pulsing quickly, and the bottom LED is on. Anything else and there's a problem. Bad socket at U9. Good CPU Reset and IRQ. Good Clock Signal.
Shotgun Approach. If replacing these chips yeilds nothing, next try replacing U5 (74LS14), which is part of the clock signal circuit (if the clock signal is good, this chip is probably not the problem!) You can also replace U7 (74LS244) and U12 (74lS240) which connect to the data lines. Also check resistors R95 and R99 (1 meg ohms) to make sure these are the correct value. Finally U10 (a MC34064 transistor that is part of the reset startup circuit) can be replaced. Address and Data Lines. Using your DMM set to continuity, check for continuity of the A0-A12 address lines between the U4 CPU 6809, the G11 ROM, and the U8 RAM chips. Also check for continuity betwen the D0-D7 data lines between these three chips. There should also be continuity between the A13 line on the G11 ROM chip and the U4 CPU 6809. After you have done that, check for continuity of the A0-A15 address lines and D0-D7 data lines between the U4 CPU 6809 and the U9 WPC chip. If you are missing continuity between any of these, the CPU will not function! You may have to use wire wrap to fix any breaks.
3s. When things don't work: Game Specific & Miscellaneous Repair Tips. Problem: The game clock won't keep time. The internal time clock appears to be running very slow, only about 25% of real time speed. Numerous spot checks show that it advances about 6 hours per day. The batteries, which when weak can cause the clock to lose time, but these are brand new. Answer: First check the batteries again! Make sure they are installed correctly. If the middle battery is installed the wrong way, this will cause a low memory protect voltage. Although game statistics will be saved, the clock will stop every time the game is switched off. All batteries should be pointing the same direction. The clock function is handled by U9 (the ASIC chip) and U21 (a CMOS 4584), and the 32.768KHz crystal. I have seen where both legs of crystal X1 were soldered to the same trace, and looks like it came from the factory that way. After removing the crystal and putting both legs in the correct locations, the time tracks correctly. The 32.768 KHz crystal is very common and used in everything from wrist watches to computers to anything that keeps time. The reason for that particular frequency is 2 to the 15th power equals 32,768. The frequency is very easy to divide by two, fifteen times, using flip-flops or some other form of divider network. This nets a one second time increment. Since the crystal was shorted, the oscillator was free running at a RC-determined frequency that undoubtedly drifted with temperature and miniscule voltage changes, hence the accumulated errors. Problem: I can't enter my high score initials on Funhouse. The game works fine, but won't let player advance through the initials by pressing the flipper buttons when a high score is achieved. The start button works correctly as "enter", and the flippers work fine in game play. Answer: there are two optocouplers on the power driver board at U7 and U8 that are numbered 4N25. If these go bad, they will prevent the flippers from moving through the high score initials. Since this game does not have fliptronic flippers, these optocouplers don't effect the flippers themselves. When the advent of the Fliptronics board, these (no longer used) optocouplers were eventually removed from the driver board. Problem: My Twilight Zone's dot matrix display shows random vertical lines. At first it was just occassionally during game play, but now they appear from the moment I power on the game. The problem has gotten worse, and now every time I turn on the machine, all four flippers energize. Answer: the problem was a bad ribbon cable. There is a single ribbon cable that goes from the CPU board to the fliptronics board to the sound board to the dot matrix controller. If the ribbon cable was mis-installed by one pin, or the cable has torn at its connector, this problem can happen. The ribbon cable houses the address and data lines to the fliptronics, sound and dot matrix controller. Often the ribbon cable's connectors can just be dirty, so reseating the connectors sometimes fixes this problem. If the ribbon cable is damaged, mis-installed or the connectors are dirty, strange things like this can happen. Another potential cause could be the lack of 12 volts getting to the dot matrix display controller board. Problem: The flippers and dot matrix display died while playing a game. The flippers on my Indy Jones died. The dot matrix display only has one vertical line which is always lit. The GI lamps are fine, as are the controlled lamps. I turned the game off and back on, the game continually launched balls from the ball trough. Answer: the +12 volts has died, probably from a bad fuse at F116, or maybe a bad BR5 bridge. Some dot matrix power is derived from the +12 volts, and the +12 volts also powers the optos (hence the auto ball launching problem and no flippers). If the +12 volts is good, unplug the fliptronics and sound board ribbon cable, leaving just the dot matrix display plugged in to the ribbon cable. Now see if the display clears up and you can see the error report. Problem: Strange Error Message when I turn my Creature from the Black Lagoon on. I get the error message "check switch #F6 U.R. Flipper". But this game doesn't have an upper right flipper. Answer: Every flipper opto board has two optos. One is wired to the lower and the other to the upper flipper switch inputs. This is true even on games with just lower flippers. If the flipper opto board has a dirty opto, you can get this error, even if your game doesn't have the flipper reported in the error message. Clean your flipper opto board optos with a Qtip. Replace the opto if the problem doesn't resolve. Another trick is to link the two opto outputs together at the flipper opto board connector. Just add some solder at the connector between opto board connector pins 1 and 2, joining together the pins for S1 and S2. This will "fix" a failing opto as the good opto takes care of both opto switch outputs. Problem: The backbox beacon light on my Getaway is constantly running after I put it in test mode. Capacitor C11 (15,000 mfd 25 volts) on the driver board gets really hot and starts smoking. Answer: Install a 1N4004 diode on the bottom end of the large ceramic resistor right above the test point for +20 volts DC on the driver board. Install the diode with the banded end going towards the driver board. The non-banded side goes to the bottom side of the ceramic resistor. This diode prevents feedback voltage from going back to the driver board, and damaging the C11 capacitor. Problem: Star Trek Next Generation diverter coil stuck
on! Answer: If the two diverter coils lock on after a game is started, check the violet/green tie-back wire which connects to the playfield's single drop target coil. This wire than daisy chains to the other coils controlled by the auxiliary driver board. It's not a bad idea to add a second back-up wire from the single drop target coil (or another adjacent coil) to the circuit board, just in case one wire breaks. Additionally, add two 1N4004 diodes to each of the under-the-playfield diverter coils (banded side of the diode to the power lug with the thick wire). Also check D7 and D15 on the aux board with a DMM's diode test (and while you're at it test TIP102 trans Q7 and Q15). With the coil power fuse removed, you can also test U1 pin 13 and pin 8 with a logic probe or DMM - if high (and the diverter is not supposed to be energized), then that U1 is bad (74LS576). That is, the U1 pins that connect to the driver transistors are normally high (when an output U1 pin goes low, the driver transistor completes the ground path for its associated coil). So a logic probe or DMM is useful to look at the U1 output pins (anything low and the associated coil will be energized). Another test of this is to use an aligator jumper wire connected to ground, and touch each U1 output pin - the associated coil should energize. The Aux8 U1 chip is driven through the ribbon cable from the CPU board's U7 chip. A damaged cpu-to-aux8 ribbon cable can also cause some wacky behavior. Also make sure the diverter coils are the correct type and resistance. The correct coil type is very important (AE-25-1000, but always confirm with the manual). Remove one wire going to each coil, and measure the resistance with a DMM. It should be around 12 ohms and no less. Another common problem is when moving the game and the backbox is laid down, the ribbon cables get pulled, and it wasn't plugged in fully on the board. So if a wire in the ribbon cable is faulty, a diverter coil can lock on and burn and ruin its associated driver transistor on the auxiliary board in the process. Finally, these 8-driver Auxiliary boards are not necessarily exchangable between game titles. The boards are the same, but there are a set of four jumpers on the Aux board, and the jumpers vary depending on the game title. So if a Aux8 board is transplanted from say Demo Man to STNG, make sure the Aux8 board jumpers are changed accordingly.
Problem: Star Trek Next Generation cannons work intermittently, or upon power on, the cannon(s) continue to rotate and won't stop (this applies to many other games with similar cannons, such as Terminator2, or other similar moving devices like the Trolls on Medieval Madness). Answer: The constant back and forth movement of the wires leading to the moving device cause an intermittant break in the wires. Usually this break can not be seen, since it is inside the insulation covering the wire strands. Usually the break is at a wire tie or some major angle. Checking the wires using the a DMM continuity setting is helpful, but does not alway work. On Star Trek Next Gen, just replace the cannon wiring loom! (Believe me, they need replaced, it is a high wear part.) They are available from pinballheaven.com/cannon.htm. After replacing the Star Trek cannon wiring loom, check the optics for each cannon in the switch test (the optics tell the game when a ball is loaded in a cannon). If an optic is dead, this can can confuse the game too. Finally, sometimes the cannon plunger becomes magnetic, and will stick in the fired position (and this in turn will block the cannon opto, confusing the game). Replace the plunger to fix this. Problem: My STNG (Star Trek Next Generation) has random multiball problems, and I have done all the ball trough upgrades, as described earlier in this document. Answer: This was a combination of problems including dirty optos below the playfield in the diverter tunnels, and a not properly working drop target below the borg ship. Even if the optos are cleaned and appear to be working normally in the switch test, an opto transmitter or receiver may be staerting to go bad and cause intermittent problems. This is especially common in STNG and diagnosing it can be a headache. On a STNG (user reported), every time the game initialized with six balls in the trougn, it would load the first ball into the right gun, then immediately kick it out, but then then next 3 balls loaded normally one into each popper. Then during game play, an extra ball would randomly be kicked out from the upper left popper. All of the optos tested normally in the T.1 switch test and the connectors and were all well seated. Finally diagnosed this by leaving the game on for a while in the switch test mode T.1 and eventually the bad opto showed up in the test (in this case it was #33, the right gun #2 opto), showing as the last switch activated. During game play, the opto occasionally must have blanked out and the game sensed an extra ball at that gun and kicked a ball out. Replacing the bad opto pair solved the problem. Problem: On STNG (Star Trek Next Generation), when I turn
the game on, it constantly tries to load balls in the under ball
runways. Answer: the game is trying to load the two guns endlessly (the machine loads a ball under each gun at initialization). It should put one ball in the upper tunnel and one ball under the left gun, and one under the right gun. Then three balls should stay in the trough. Be aware if fuse 103 on the Power Driver Board is blown (3A slow blow), the game will not start and will constantly throw out balls. Fuse 103 powers the solenoid which controls the upper diverter on the under-the-playfield diverter. Without a working diverter, the game can't load the balls where it wants, and the game will attempt to load and reload balls continually. As a test, try this: go into the feature adjustments and set both guns to "Broken=Yes". This will disable the guns. If the machine then starts up OK, you have a problem with a gun assembly optos, or the under-playfield diverters. Enable each gun individually to see which one causes the failure. Also a dirty/broken opto in the upper tunnel can cause this problem. Problem: The Frogs are missing on my Scared Stiff. Where can I get replacements? Answer: The frogs used in Scared Stiff are standard toys, with a slight modification. The bottom of the frog is drilled and tapped for a threaded rod. Often the frogs and their associated rods are missing. Replacements can be purchased from pinballheaven.co.uk. Problem: How do I prevent playfield wear around upkickers? Answer: Cliffy (www.passionforpinball.com) and Mantis Amusements (mantisamusements.com) sells metal protectors that can be attached to the bottom of the playfield, preventing this wear. They are also available in Europe from pinballheaven.co.uk. Problem: Shadow Battlefield Optical Sensors work intermittently. The battlefield would sense a ball on the sides of the battlefield, but not when the ball was in the center of the battlefield! Interestingly, the problem went away when the playfield glass was removed. Answer: The ball is "seen" by optics on the battlefield. The beam of light provided by the optic transmitter is too wide/conical. So wide, the light was reflecting off the playfield glass and back to the optic receiver (that's why removing the playfield glass solved the problem). The solution to this is to put a piece of 3/8" long black heat-shrink tubing (without shrinking it) over the optic transmitter (and maybe the receiver too, if needed) to sheild the light beam into a tighter pattern. Problem: None of my Whitewater's coin door buttons do not
work! There is a shared ground wire that "daisy chains" (goes between) all four coin door buttons. Check that this wire hasn't broken. Also all the coin door buttons are electronic buttons. If the game is missing its +12 volts digital power, these buttons will not work. Check fuses F114 and F115. The red 12 volts LED on the power driver board should be lit also. Problem: On my Indiana Jones, the Path of Adventure mini-playfield "stutters", when it moves in one direction during game play (but not in diagnostic mode). Why? Answer: The PoA (Path of Adventure) uses the flipper buttons during game play to move left or right. If the flipper opto board's "U" optics are dirty/failing, this can cause the PoA to "stutter", as it moves. Also the game uses two "U" optos on the POA switch board (mounted against the back inside panel of the playfield), and these too could be failing. Use a Q-tip and some Windex, and clean the flipper board optics and the POA switch board optos. Now go to the POA test in the diagnostics. Does the POA stutter in diagnostic mode? If so, the POA switch board optics are failing and need to be replaced. Now retest in diagnostic mode. If the POA works fine in diagnostic mode, but the POA still stutters in game mode, replace the flipper "U" optos (if the POA stutters to the left, it's the left flipper opto board). Another way to test if the flipper optos are the problem is to swap the right and left flipper opto boards, and see if the problem moves to the other side. Note in the diagnostic mode, the coin door buttons are used instead of the flipper optos to move the PoA. This is why a flipper opto problem does not show any problems in diagnostic mode, but only in game mode! Problem: On Bride of Pinbot, the game does not show the correct "face" during game play. Answer: Under the playfield, there is a small circuit board with a relay on it. This relay controls the direction of the motor, which controls which face is shown. Usually the solder joints on this relay crack, causing the relay to not always engage, and showing the wrong face during game play. Resolder the relay's solder joints to fix this. Problem: On Tales of the Arabian Nights (ToTAN), after six "Tiger loops" are made for the extra ball, the game shuts down! Answer: This seems to be a software problem in all versions of the CPU ROM code. The problem is caused by switch 45 (inner right loop) not working. After the extra ball light comes on, the software compensates for the non-working switch 45 by resetting the game! To fix the problem, make sure switch 45 is working correctly. Problem: On Roadshow, the bulldozer blade refuses to go
up. Answer: Check the two "U" shaped optos on the dozer opto board, which determine the position of the dozer blade. If either one of these "U" optos has failed or are dirty, the dozer blade will not work properly. Sometimes these optos will seem to work correctly while in the diagnostic switch test. But if they are starting to fail, instead of giving a solid 0 volt or 5 volt signal, they give something in between (like 0.4 volts). To fix this, first try and clean the optos with a Q-tip and some Windex. If still a problem, replace the "U" optos. Problem: On Getaway, the rotating beacon on the top of the
backbox is missing. Answer: HAPP Controls makes a great replacement for this 12 volt beacon and lamp. Call HAPP at 888-289-4277 (BUY-HAPP) and order part number 95-0115-10UC. Price is right around $40. This is a red beacon light assembly with a chrome ring and outer mounting plate. The HAPP motor is DC, and the game's driver board supplies AC voltage. To convert the voltage to DC, use a 35 amp 200 volt bridge rectifier (as used on the driver board). Connect the two wires coming off the small beacon board to the AC leads of the bridge. Connect the two wires coming off the beacon to the "+" and "-" leads of the bridge. Problem: On Indy500, the lighted targets have broken off the plastic opto activators (the part that passes between the "U" opto. Answer: Use some Duct tape or electrical tape and tape both sides of the plastic stub that is left on the target, so the tape is sticking to the stub and itself. Then trim the tape with a razor blade. Note the reason the plastic tab breaks is because the two foam pads on either side of the clear target that prevent the plastic flag from hitting the back of the opto are missing. These can be easily replaced with new 3/16" weatherfoam on the sides of the target to prevent non-broken target tabs from breaking in the future. Problem: On Johnny Mnenomic, the glove does not work. Answer: First, remember the glove motor works off the 20 volt flash lamp circuit. So if the coin door is open, the glove motor will not work. Therefore if the coin door is open when the game is turned on, the power-on glove test will fail, making the glove not work (until the game is reset). On the last Johnny I owned, I wired the coin door interlock switch so the 20 volt flash lamp circuit didn't turn off when the coin door was open (the 50 volt solenoid circuit was still disabled with the coin door open). I found this to be much less confusing and more convenient when I was working on the game (I typically leave the coin door open to turn off the 50 volt solenoid power). Go to the solenoid test and make sure the hand magnet works. Often because of the movement of the hand, the wires going to the hand magnet fatique and break inside the wire's insulation (so a wire break is not obvious). If the driver board fuse is good (I believe it's F103), there should be 70 volts at both leads of the magnet wire. If there's only voltage at one magnet lead, there's a break in the wiring. I found these magnet leads often need to be replaced with new stranded wire. The same also applies to the ball-in-hand switch. Again movement of the hand fatiques the wires going to this switch. Test the switch in T.1 diagnostic test. It's just a leaf style switch with two wires going to the ball-in-hand switch blades. This switch is located inside the magnet, under the moving glove. Use a *pinball* to check if this switch (labeled "F5" in the switch matrix, right most column) is working. It is important to test this switch with an actual pinball (opposed to just using a finger). The glove on JM uses four "U" shaped optos (for X/Y direction), two microswitches to locate the center and left most position of the glove, and a switch inside the hand's magnet. Test these switches by going into the WPC diagnostic switch test T.1. One microswitch finds the "mid" position of the hand (forward and back). The other microswitch finds the left most position of the hand. Make sure both of these micro switches are working in the switch test T.1 by activating them manually. Then make sure when the glove moves these switches actually close. Next check the four "U" shaped opto switches for the glove. These four optos tell the computer the X and Y position of the glove. They are mounted on two small PC boards, positioned behind the back panel of the playfield (pull the playfield all the way forward to see these). The glove moves much like a Genie garage door, on threaded rods (one rod for X movement, one for Y movement). Each rod has a metal interuptor, which rotates between two "U" shaped optos. The threaded rods can be spun by hand. In switch test T.1, make sure both optos ("A" and "B") work for each rod (these "U" optos are the five leg variety). If just *one* of these four optos does not work, the entire glove assembly will not work, and an error report will be generated when the game is turned on (or when entering diagnostics). The error relating to these optos is "No X Movement Detected" or "No Y Movement Detected". This signifies a problem with any one of these four "U" optos. If one of these "U" optos does not work, or works intermittently, just replace it (see here for info on replacements). Another problem can be the small .100" molex connectors on the glove's two opto boards. Often just reseating these connectors will fix a glove opto problem. If reseating does fix the problem, it is suggested the connectors be replaced. Also check the header pins for cracked solder joints on these two opto boards. Also check the glove direction motor board mounted under the playfield. Often there are cracked solder joints around the header pins on this board. Resolder the header pins to fix this. After all switches are confirmed as working, go into the solenoid test and make sure the glove's magnet is working. Last, make sure the latest CPU ROM software is installed in the game. The latest is version 1.2. A new U6 CPU ROM would need to be "burned" if a game has a revision other than this (the CPU revision number is shown upon game boot up, and when entering diagnostics). Problem: My Scared Stiff crate LEDs are broken. Where can I get replacements? Answer: The crate LEDs are standard red T-1 sized LEDs. Any T1 LED should work, but here are some that mimic the originals, from mouser.com, part# 604-L934SRCD, KingBright super bright LED lamps T-1 red water clear, $0.34. Or part# 351-3230, LED lamps T-1 red water clear, $0.25 as a second choice. Problem: My Cirqus Voltaire neon lamp is not working. Answer: First check that 12 volts is present going *into* the neon lamp's transformer (is the fuse blown?) The easiest way is to check for 12 volts at the Molex connector going to the transformer (under the playfield), or at the power driver board. Past that, if the neon tube itself is not damaged, the transformer itself is probably bad. The neon transformer takes 12 volts DC and converts it to a very high voltage (about 1500 volts, at low current). Because of this, to get the UL rating, Williams was required to rivit close a plastic case around the transformer! To access the transformer, the rivits will need to be drilled out with a 1/8" drill bit or grind off the heads of the rivets (on SWE1, do not try and remove the decorative plastic "light saber handle" from half of the plastic transformer case; they uses silicon to attach it, and it does not come off without destroying the decorative plastic!) Once the rivits are removed, the transformer can be removed and checked. Is there any high voltage (1500 volts DC) being output? If your DMM does not go this high, just replace the transformer. The cheapest way is to buy a car neon license plate transformer. If needed, wire the automobile neon transformer under the PF (if it doesn't fit in the ramp housing), and run the high voltage wire up to the ramp and bulb. Note if you do this to be sure to use wire rated for at least 2000 Volts (it'll have thick insulation; look at the wire already on the bulb if you need some reference). Specs for the original neon transformer are here. But basically these are the specs: The original Williams Star War Episode 1 transformer (part number 04-10947) may also still be available. The original transformer for Cirqus Voltaire (and SWE1) was a Ventex model VT12D5, but they seem to have changed their model numbers so now it's VT1510-12. A replacement is Ventex model NPS-12D5 and it fits and works fine. Key specs are input 12 volts DC at 0.6A, and output 1500V 5mA. You can find it at http://web.archive.org/web/20081023080129/http://www.ventextech.com/lowv.htm. Note the output connector will need to be changed to a Molex connector. Another transformer source is http://web.archive.org/web/20081023080129/http://www.sunsupply.com/transformers/winind.html. After getting the new transformer test it using some aligator test leads, and hook it up to the game's 12 volts and to the neon tube. Make sure everything is safe and insulated and turn the game on (remember 1500 volts output!) After you're sure the new transformer is working properly, reassembly the ramp. You can use small screws instead of rivets if you don't have the proper rivets and rivet tools. Testing the neon tube itself, without using the high voltage transformer, and not that easy. There is no to test a neon tube with a DMM - basically the gas inside the tube conducts electricity. So a DMM can't generate a big enough voltage to test it. They make little inductive testers - the tube will glow when this thing is held near the neon tube, if the gas is still in there. Also try taking the neon under some high voltage power lines at night to see if it glows (and to scare yourself about how much energy is leaking out of them!) Problem: In my Getaway High Speed2 the The ball does not accelerate well around the super charger, and was blowing fuse F103 after a few revolutions. Also all three magnets seemed to pulse no matter which supercharger opto was activated. Answer: Clive suggested the problem may be one or both of the CMOS chips on the Accelerator board, or the LM339's on that board. By checking the accelerator optos in switch test mode, verified the optos all work fine and there were no multiple openings for each opto. If this tests good, the LM339 chips are probably fine. This leaves the CMOS chips U2 (4011) and U3 (4071) as suspect, so replace those. Problem: Where can I get a replacement strobe light tube for my Attack from Mars? Answer: Though replacement strobe lights can be gotten at local discount stores and Pep Boys, they are really not the correct replacement for your AFM game. The proper strobe rate for AFM is 6.25 lights per second. The inexpensive replacements will only allow maybe 2 or 3 lights per second. What is needed is a "low-pressure" horseshoe type of strobe light. The low-pressure is key, because it allows the strobe capacitor enough time to charge and discharge, lighting the strobe 6.25 times per second. The proper strobe light is available from http://web.archive.org/web/20081023080129/http://www.pinbits.com/ (go to the AFM parts section). When installing don't touch the bulb. And before assuming the bulb is bad check the power supply board mounted under the metal box in the back. Make sure the game is unplugged before taking it off. You need to take it off anyway to take the strobe assembly off. I had two leads broken off on the small blue box on the board on a recent repair job. Problem: On Medieval Madness the ball hits the trolls, but doesn't always register a hit. Answer: There are two main reasons why the troll would only register hits intermittently, or not at all. The first is that a one of the soldered wire connections on the switch attached to the troll head has broken. The second is that the contact rivets have become loose on the switch blades on the troll head switch, allowing only an intermittent connection at best. To fix the problem of loose contact rivets remove the switch assembly from the troll head assembly and then peen (flatten with a small hammer) the switch stack rivets so this removes any play in the switch stack, allowing for good contact with the switch blade. Problem: Monster Bash sometimes slam tilts when the ball goes down the right outlane. Answer: Check the switch behind Frank, airballs will short the switch causing the problem (only when the frank targets are raised). Problem: How do I link two NBA Fastbreak games together? Answer: (from Louis Koziarz) the NBA Fastbreak link option is done through the A/V board's serial port. Installing a serial port on WPC-95 games is easy, and you can save the money by doing it yourself instead of buying the kit. The WPC-95 A/V board comes with those two serial port chips missing by default, so these chips will need to be purchased and insert them into positions U22 and U24 on the WPC-95 A/V board. U22 is a MAX239 RS-232 driver chip, and U24 is a 16C450 UART. Digi-Key (www.digikey.com) is currently selling the MAX239 for $7.55 and the 16C450 for $5.60 (using a buffered 16C550 as an equivalent part). The pinouts for the A/V board are on page 9 of the schematics, but here's a summary: For basic RS-232 operation, all that is needed are the first three signal lines, and you should be able to talk to the board. If not familiar with RS-232 interfacing, obtain a copy of the WPC-95 Schematics, as these go a long way in helping understand how the system works. If the chips are installed properly the operating system should detect the board automatically and start sending audits out the port. It may need to enable printouts in the Adjustments menu, I don't remember if that option trips automatically. That's all there is to it. NBA Fastbreak also used this port in a null-modem configuration for the head-to-head gameplay (swap TX and RX lines between games). Linked game play works like this: the first player presses Start, and their display shows "Waiting for 2nd player." You can play a stand-alone game by pressing both flipper buttons, or press Start on the second machine for a linked game. Linked games are broken down into four quarters, with a halftime. The quarter length can be modified in the menus. The gameplay is constant, there is not limit to the number of balls (because it's a timed game). If a player drains the ball, a new ball is served with no penalty (other than the time this takes). The head-to-head players select their teams and play begins. The players work together to complete modes. For example, player 1 might complete the two left "in the paint" shots, and player 2 may complete the two right "in the paint" shots, which allows that mode's multiball to start. If both players complete all modes and reach the final (wizard) mode, they compete for the championship ring(s). If there is a tie the game goes into an extra overtime period. Problem: What motor is used in my WPC game? Answer: See the web page gearbox.htm for details. Problem: The auto adjust Eddy Sensor board in my Monster Bash or Circus Voltaire has the LED continually flashing (instead of coming on when a ball approaches the PF sensor, and off with no ball near the sensor). Answer: The auto adjust Eddy LED will flash if 1) You don't have the coil plugged into the auto eddy sensor board, 2) You have the wrong (resistance) coil plugged into the eddy board, 3) You have the wrong value capacitors for C1 and C2 installed in the eddy board. How can the caps be the wrong value? If the eddy board was transplanted from Circus Voltaire to Monster Bash (or vice versa), this can happen. Check yor game manual for the correct cap values. Problem: On my Twilight Zone, I get the error, "clock is broken". How do I fix this? Answer: On my TZ clocks, this problem occurs because of high heat inside the clock from the #86 General Illumination lamps. To fix the problem, all the "U" slot optos should probably be replaced (along with the feeding 470 ohm 1/2 watt resistors R1-R8, and the .100 interboard connector), and the heat some how decreased inside the Twilight Zone clock. There are two trends on decreasing the heat inside a TZ clock: Using diodes on the clock's #86 GI lamps, or installing bright LEDs instead of the #86 lamps. If the clock's heat issue is not address, the internal heat will cook the "U" slot optos and other parts, giving a "clock is broken" error message. Rottendog Amusements and Pin Lizard sells replacement TZ clock boards with bright LEDs already installed. Using their boardset, the internal heat can be reduced from about 160 degrees in an unmodified clock, to about 100 degrees. But if using the original boards, they can be modified for LEDs to reduce the internal clock heat to about 125 degress. This will decrease the power consumed by the clock from about 8 watts to 1 watt (as documented by PBliz), thus reducing heat. The existing TZ clock boards can also be modified for LEDs. To do this, first get four T1-3/4 size (5mm diameter) water clear white LEDs (PBliz suggests Digi-Key, part# CMD333UWC-ND). The brighter the LED, the better for this application. Also get four 100 ohm (or 133 ohm) 1/2 watt resistor, and install them in locations D1-D4. Bend the LED leads as shown in this photo here. This spreads light more evenly over the clock face (click here and here). Note that the LEDs can be installed in either direction; there is no need to pay attention to how the LED's "flat spot" is installed (since the supply current is AC volts). But since the supply voltage is AC, it is ideal if the LEDs can be mounted so two are "on" and two are "off" during any half of the AC cycle (see the picture above for this mounting configuration). Please remember, just putting in LEDs does not fix previously damaged boards. Often original clock boards will have burnt traces, bad "U" optos, bad opto resistors R1-R8, a damaged .100" inter-board connector going between the two clock boards, or cold solder joints on the interboard connectors. Also the look of clock LEDs is quite different than the #86 bulbs; it is a more blue colored light. Some people don't like this look, as it is not "stock". There is another clock modification which retains the original look of the clock (some people do not like the look of LEDs). Four 1N4004 diodes can be installed at locations D1-D4 on the clock board (Williams actually has zero ohm resistors installed there), and the original #86 bulbs can still be used (the diodes will decrease the current to the #86 bulbs, lowering the internal temperature). Also install the D2,D3 diode bands in the reverse of the silkscreening on the original clock board. This will cause lamps one and four to light on one half of the AC cycle and lamps two and three to light on the opposite half of the AC cycle. This mod will decrease the consumed clock power from 8 watts to about 6 watts, lowering the heat yet still retaining the original look of the clock. With this modification it is recommended the plastic clock housing be drilled on the top with two 1/4" holes to vent the heat, directly above the top two #86 lamps (no bottom holes are needed since there are already bottom holes for the connectors). Problem: How do I prevent my Addams Family magnets from burning my playfield? Answer: The three under-the-playfield mounted magnets are energized by a small board with three TIP36 transistors (mounted under the playfield). If one of these TIP36 transistors shorts on, the magnet will stay on, and could get hot enough to burn the playfield. To prevent this, it's a good idea to install three 2amp slow-blow fuses (one for each magnet) under the playfield. This way if a magnet locks on, the fuse for that magnet will blow before the magnet gets hot enough to burn the playfield.
|
|
4a. Finishing Up: Rebuilding Flippers
Flippers get weak because they have moving parts that get substantial use. When they wear, the mechanisms get play (slop) in these moving parts. Instead of the flipper coil transmitting all its energy in propelling the ball, some energy is absorbed by the sloppy mechanisms. Rebuilding the flippers removes this slop, and will dramatically increase the strength and feel of your flippers. How Flippers Work. To simplify how the two sides of a flipper coil work, it's best to examine the non-fliptronics version. In this case, when the flipper is energized and at full extension, the normally closed EOS switch opens. This removes the high powered side of the coil from the circuit. The low powered side of the flipper coil is always in the circuit, but is essentially ignored when the high powered side is in the circuit. This happens because the current takes the easiest path to ground (the low resistance, high power side of the coil). The low power high resistance side of the flipper coil won't get hot if the player holds the flipper button in.
Pre-fliptronics games have a high voltage, normally closed end-of-stroke (EOS) switch. But Fliptronics flippers are basically an electronic (instead of mechanical) version of the above explained non-fliptronics flippers. The main difference is fliptronics flippers have EOS switches that are low voltage, normally open switches (instead of high voltage, normally closed as used on non-fliptronics flippers).
When the player presses the flipper button, the high-powered side of the flipper coil is activated and fully extends the flipper. Then the end-of-stroke (EOS) switch is opened, and removes the high-powered side of the coil from the circuit. As the flipper reaches it's end-of-stoke, the flipper pawl opens the high voltage, normally CLOSED switch. The electricity now only passes through the low powered side of the flipper coil. The use of the low powered, high resistance side of the flipper coil consumes less power. This allows the player to hold in the flipper button without burning the flipper coil. If the high-powered side of the coil was activated alone for more than a few seconds by itself, the coil would get hot, smoke, smell, and burn. Non-Fliptronic EOS switches use a 2.2 mfd 250 volt capacitor (part number 5045-12095-00). This minimizes the high voltage electrical arc between the contacts of the EOS switch. The EOS switches on these games do need periodic maintainence. Since they are high voltage switches, there is some electrical arcing. This will cause the switch contacts to pit and burn, and cause some resistance. As the resistance increases, more arcing occurs (which causes even more resistance). Eventually, bad EOS switches will make the flippers very weak. They must be filed clean with a small point file periodically. The switch contacts are made of Tungsten. Fliptronics WPC Game Flippers. The EOS switch is now a low voltage, normally OPEN switch. As the flipper pawl reaches its end of stroke, it now closes the EOS switch. When the player presses the flipper button, the CPU turns on the high powered side of the flipper coil. When the EOS switch is sensed closed, the high powered hold side of the coil is turned off. If for some reason the EOS never closes, the CPU turns off the high powered side of the coil after a short period of time (a few milliseconds). The low-powered hold side of the coil is powered for as long as the player holds the flipper button. Computer control of the flipper coil via the Fliptronics board provides an extra level of reliability to the game. The computer now controls this. The EOS switch is monitored, and if the computer sees a problem, the operator is notified via a diagnostic message. But if the operator chooses to ignore this, the game will still function as designed. Also, since the EOS switch is now a low-voltage, gold plated contact device, it requires no big maintanence schedule. Flipper Coil Numbers and Strength.
Flipper Rebuild Kits.
Get the Correct Flipper Parts When Possible. Pinball Life (and to a lesser extent Pinball Resource) have taken this into account and have started to have custom flipper plungers and coil stops manufactured to the correct specs. For this reason I suggest buying your parts from these people. But I understand this is not always possible, and I have shown in this document how to use the 'generic WPC' (Pinball 2000 spec'ed) flipper parts in a WPC game, and to get proper flipper travel. In the case of Pinball Life, they break flipper rebuild kits into three WPC categories:
First, use your allen wrench and remove the two 10-32 x 3/8" bolts that hold the coil stop in place. This will release the coil from the assembly. Move the coil to the side for now. Examine the coil stop. Often, the coil stop will have a "mushroomed" head. This happens from the coil plunger slamming into the coil stop. If this is the case, replace the coil stop. In a pinch, you can re-work the coil stop and file the mushroomed head flat and bevel the edge. The problem with this is plunger travel length increases. If excessive, the plunger link could now slam into the top coil bracket, destroying it. Also the increase in plunger travel can cause the flipper pawl to hang on the EOS switch (leaving the flipper in the up position). New coil stops are cheap, so I suggest just replacing them. For WPC-DCS and WPC-95 games, use coil stop #A-12390. For pre-WPC-DCS (Addams Gold being the last WPC-DCS game) and WPC games (and system 11 games), use coil stop #A-12111. If the newer #A-12390 coil stop is used on an older WPC game, the flipper bat will have less travel. Two allen head tempered black 10-32 x 3/8" bolts are used to hold the coil stop. If the used coil stop is worn, there can be problems with the flipper pawl hanging on the EOS switch, especially on fliptronics flippers.
On Fliptronics flippers, remove the one side of the return spring from the flipper pawl. Then using your allen wrench and an open 3/8" wrench (needed for most pawls, though newer style pawls may not need the 3/8" wrench), loosen (but don't remove) the bolt that clamps the pawl assembly to the flipper shaft. From the playfield side, turn and pull the flipper while holding the pawl assembly until the flipper can be pulled from the playfield. The pawl assembly can then be removed from under the playfield. Step 3: Check for Worn Coil Bracket. Step 4: Check the Rubber Flipper Plunger Stop.
The nylong playfield bushing is a nylon part that the flipper shaft passes through. It is very common for this part to crack, or wear excessively. This can cause the flipper bat to drag on the playfield finish. If this happens, ugly playfield wear marks can result (see picture above). It's pretty easy to tell if the bushings need to be replaced. With the flipper pawl removed from the flipper shaft, wiggle the flipper on the playfields, side to side. There should be some play, but not excessive play. The bushing should also stick up ABOVE the playfield about 1/8". If the bushing is too low to the top of the playfield, this will allow the flipper bat to drag on the top of the playfield. To play it safe, always replace both nylon flipper bushings. Flipper drag marks on the playfield are not worth the risk!
The flipper pawl assembly can now be rebuilt (if you buy a whole new flipper pawl assembly with a new plunger/link for about $10, skip this section). Remove the allen bolt that holds the plunger/link to the pawl. The plunger/link can now be removed (you may need to use a screwdriver to spread the pawl assembly slightly to release the plunger/link). Before proceeding, check the hole in the pawl which bolts the plunger/link to the pawl. This hole can enlongate (egg-shape), making the pawl useless. Even if a new plunger/link is installed, the eggshaped hole will create "play" in the pawl assembly. If the pawl holes are enlarged or eggshape, the pawl must be replaced (or just buy a completely new pawl/plunger/link assembly). Also check the bolt that goes through the pawl and link (and link bushing). Often its center section wears again causing play. The only solution to this is a new bolt.
Replace the flipper plunger and link. A new plunger/link can be bought cheap (rebuilding the plunger is hardly worth it. Spend the $1.50 and get a new plunger/link. If rebuilding the plunger/link is your only option, here's what to do: grind and bevel the plunger tip to remove the mushroom. Using a 1/8" metal punch, remove the roll pin that holds the link in place. Install a new link, and hammer the roll pin back in place. Make sure the new link moves freely.) Install the plunger/link and a flipper link spacer bushing. Remember the allen bolt that holds this is place goes through the pawl assembly with the nut on the same side as the pawl (see pictures).
Skip this if a new pawl was installed. One of the flipper pawl's job is to activate the EOS switch at the flipper's end of stroke. This metal pawl tab is factory coated with heat shrink tubing to prevent wear to the EOS switch. When the coating is worn, metal-to-metal contact (pawl to EOS switch) occurs. This will shred the EOS switch blade. When the EOS switch blade frays, it will hang-up on the flipper pawl. This will cause the flipper to stick in the up position (regardless of the condition of the return spring). The heat shrink tubing also provides insulation between the metal flipper pawl and the EOS switch. This is especially important on non-Fliptronics games (as the EOS switch is a high voltage switch). Worn or missing heat shrink tubing on these games can cause all sorts of strange game behavior. New pawl heat shrink tubing should always be installed when rebuilding the flippers. Cut the old tubing off using a razor blade. Cut a 1/2" length of new 1/4" heat shrink tubing. Push it over the pawl, and use a heat gun or hair drier to shrink the tubing in place. Trim with a razor blade as needed.
Often, operators will replace a flipper coil with the wrong type. This happens quite often. You should verify in the manual that your particular game has the correct flipper coil installed. Step 9: Re-install the Flipper Pawl Assembly and Flipper Coil/Coil
Sleeve. Put a new coil sleeve in the flipper coil. If you can't get the old coil sleeve out of the coil, replace the entire coil (it has been heat damaged otherwise the coil sleeve would easliy slide out). The coil sleeve should be installed from the non-terminal end of the coil, and extend through the coil at the terminal end about 1/8". Put the flipper coil in place, the coil end with the wire terminals goes closest to the flipper pawl. Note the nylon "tab" that is molded into the the nylon terminal portion of the coil. This tab will fit into a notch in the coil bracket. The extended part of the coil sleeve will go through this coil bracket too. Install the coil stop and its two allen bolts.
Williams changed flipper return spring styles in 1992. Before, there was a cone-shaped flipper return spring that went over the flipper plunger. The problem with this set up was it chewed up the flipper link, and often the spring just got weak and broke from the constant contact with the flipper link. To combat this problem, Williams made two changes when they went to Fliptronics flippers. First they changed the style of flipper link to be thicker, and have a more rounded contact point. Second they stopped using a plunger style return spring. The return spring was moved outside of the plunger, where it takes less abuse and doesn't chew up the flipper link.
Step 10: Check for Flipper bat up and down movement.
On the top of the playfield, note the roll pin inserted through the playfield, just behind the flippers. This pin is used for alignment purposes at the factory when the playfield was first assembled. Some people put a toothpick into the roll pin, and move the flipper against it (with the rubber installed or not installed, it varies from game to game). This will give you a general idea of where the bat should be aligned. I wouldn't suggest trying to push the roll pins back through the playfield for flipper alignment; just use toothpicks. No need to possibly damage the playfield. Unfortunately the toothpick alignment is really not the proper way to align a flipper. Instead take a straight edge and use the lane guides to give the flipper bats a final position adjustment. The ball should roll off the guides and to the flipper bat in a straight line, which should be easy to see with the straight edge.
When you are finished, extend both flippers to the up position. They should look "equal", both extending the same amount. If not, you will need to re-align one or both of the flippers. If you didn't replace the flipper coil stops (and instead filed them down to remove a mushroomed head), the flippers may not line up when extended. This happens because the plunger travel has increased from filing the coil stop. Also worn rubber flipper plunger stops can cause the flippers to not align with fully extended. Step 13: Check/Adjust Flipper Travel.
Now you are ready to tighten the flipper pawl assembly to the flipper shaft. With the flipper positioned correctly, lift the playfield and tighten down (very tight) the flipper pawl assembly's allen bolt. Use an allen wrench and a 3/8" open wrench (if needed). If the flipper spacing tool is still in place remove it and the toothpick. Step 15: Cleaning and Adjusting the EOS Switch. On non-fliptronics games, clean the EOS switch contacts with a file. There should be no pitting in the contacts when done. The EOS switch is a normally closed switch. So adjust the non-fliptronics EOS switch so it opens about 1/8" at the end of the flipper's stroke. On fliptronics games, clean the EOS switch contacts with a rag and some alcohol. Or clean the EOS switch by running a business card through the closed contacts once or twice. The EOS switch is a normally open switch. So adjust the fliptronics EOS switch so the contacts close when the flipper is at its end of stroke. Adjust the EOS switch to close at near the end of the flipper bat travel Make sure the EOS switch doesn't hang on the flipper pawl when the flipper is fully extended. Last, turn the game on and put it into diagnostic test mode. Close the coin door (to turn power on to the flippers). Now press the cabinet flipper buttons and AGAIN check the EOS switch spacing and adjusted as needed. Parts Reference. 4b. Finishing Up: New Coil Sleeves
4c. Finishing Up: Protecting Slingshot Plastics
4d. Finishing Up: Cleaning and Waxing the Playfield
Williams recommends using Novus 2 plastic polish for cleaning playfields. It works great, and leaves a great shine. It's very gentle, yet cleans fast and well. It can be used on both the playfield and on plastic ramps. I buy it at my local grocery store, but you can also get it through most pinball retailers. There are a number of products available for cleaning the playfield that should not be used. Millwax and Wildcat 125 come to mind. Avoid these products. Millwax and Wildcat aren't even really waxes. They are cleaners with extremly small amounts of wax and lots of solvents to keep the cleaner/wax in an easy-to-apply liquid form. Also Millwax and Wildcat contains high levels of petroleum distillates. Williams recommends not using these products on their games. Please see this service bulletin dated October 1989.
If your playfield is Diamondplated, using a wax after cleaning is optional. All Williams playfields were Diamondplated starting with Terminator2. Prior to that, the playfield will say "protected by Diamondplate" in one of the outlanes if it is indeed Diamondplated. Diamondplate is basically a polyurathane top coating originally used to protect hardwood floors. A good HARD wax such as Treewax or Meguires Carnauba Wax works great, even on Diamondplated playfields. Ball speed will improve, and playfield wear will decrease. Both of these waxes are just that; wax! They have little or no detergents or cleaners in them. Notice how difficult they are to remove and polish after they haze (as applied per the instructions)? This is good! It means your pinball will have a hard time getting them off too. I like to quickly re-wax my playfield every 100 games with these waxes. Also a scratched ball can slow and damage the playfield. Replace the ball if it's not shiney like a mirror. They are only about $1.25 each. Throw the old balls away. 4e. Finishing Up: Playfield Rubber
I would recommend not using black rubber on your games. It looks bad, is much harder, and hence has different (less!) bounce. Black rubber is now pretty much standard equipment on most Williams games after about 1995. For an operator, black rubber gives a distinct advantage: it doesn't show dirt! This creates an illusion. For the hobbiest, I would recommend using white rubber instead. It gives a brighter look to your game. And on newer games that don't have much rubber, white rubber can give more ball bounce. Some games were designed, and looked better, with black rubber. Scared Stiff is one such games. Later new games (like Circus Voiltaire, 1997) were going to be designated for white rubber by the designer, but got black rubber installed at the factory. Clean rubber has amazing bounce properties. Dirty rubber has seriously reduced bounce. The more bounce, the more fun your game will be. If you want to try and clean your old (only slightly dirty) rubber, you can use WAX. Meguires Carnauba Wax, TreWax or even Novus#2 plastic cleaner works great on lightly soiled rubber. Just remove the rubber and wax it with a CLEAN rag, and wipe off the excess. Wax will keep your rubber supple and UV protected. You don't even have to remove the rubber if it's not too dirty. For dirtier rubber, try alcohol, Westley's Bleche White tire cleaner, or Goof-off (but be careful with Goof-off, as it damages plastic). Use a clean rag and wipe the rubber down. If flipper rubbers are wearing out quickly, reverse it (turn it inside out), and re-use it. * Go to WPC Repair document Part One at http://marvin3m.com/~cfh/wpc/index1.htm * Go to WPC Repair document Part Two at http://marvin3m.com/~cfh/wpc/index2.htm * Go to the Pin Fix-It Index at http://marvin3m.com/fix.htm * Go to Marvin's Marvelous Mechanical Museum at http://marvin3m.com |
