Scope.
This document is a repair guide for Williams and Bally WPC pinball games made from 1990 (Funhouse) to 1999 (Cactus Canyon).

Internet Availability of this Document.
Updates of this document are available for no cost at http://marvin3m.com/fix.htm if you have Internet access. This document is three parts (part one is here, and part two is here, and part three is here).

IMPORTANT: Before Starting!
IF YOU HAVE NO EXPERIENCE IN CIRCUIT BOARD REPAIR, YOU SHOULD NOT TRY TO FIX YOUR OWN PINBALL GAME! Before you start any pinball circuit board repair, review the document at http://marvin3m.com/begin, which goes over the basics of circuit board repair. Since these pinball repair documents have been available, repair facilities are reporting a dramatic increase in the number of ruined ("hacked") circuit boards sent in for repair. Most repair facilities will NOT repair your circuit board after it has been unsuccessfully repaired ("hacked").

If you aren't up to repairing pinball circuit boards yourself or need pinball parts or just want to buy a restored game, I recommend seeing the suggested parts & repair sources web page.

Table of Contents

1. Getting Started:
1. Experience, what is WPC?, Schematics
2. Necessary Tools
3. Parts to have On-Hand
4. Different WPC Generations
5. Game List
6. Lubrication Notes
7. The Circuit Boards
8. Introduction to Operation
9. Troubleshooting (quick guide)

2. Before Turning the Game On:

1. Check the Fuses/LEDs (Blown Fuses and What Causes them)
2. Burnt GI Connectors (and WPC-95 GI Diodes)
3. Quick and Dirty Transistor Testing
4. Should I leave my Game Powered On?

3. When Things Don't Work:

1. Removing the Driver board
2. Replacing Components
3. Checking Transistors and Coils (stuck on coils and flashlamps)
4. Game Resets (Bridge Rectifiers and Diodes)
5. Problems with Flippers
6. The Lamp Matrix
7. The Switch Matrix
8. Infrared Optic Switches
9. Eddy Sensors (electronic ball sensors)
10. Ball Trough Problems (random multi-ball)
11. Dot Matrix/AlphaNumeric Score Displays
12. Power-On LEDs and Sound Beeps
13. "Factory Settings Restored" error (Battery Problems)
14. Lightning Strikes
15. Sound Problems
16. General Illumination (GI) Problems
17. Test Report & The Diagnostic Dot
18. Fixing a Dead or non-booting CPU board
19. Game Specific & Miscellaneous Repair Tips

4. Finishing Up:

1. Rebuilding Flippers
2. New Coil Sleeves
3. Protecting Slingshot Plastics
4. Cleaning and Waxing the Playfield
5. Playfield Rubber

Bibliography and Credit Where Credit is Due.
Many of the ideas in this repair guide are not original. Lots of people contributed to this document, and I just want to say, "thanks!" Below are a list of the resources used in the development of this guide. Some resources/people may have been innocently left out. If this is the case, and an idea is here that was originally yours, please notify me and I will make sure to give you credit!

• "WPC theory of operation" (#16-9289), 1991, Williams Electronic Games. This is a great book, and is partially reprinted in part one of this document. Unfortunately it does not include WPC-S and WPC-95.
• "Pinball Machines: How They Work & Troubleshooting", 2nd edition, 1993, Norbert Snicer, ISBN 0 646 11126 4. Another great resource, but unfortunately it also does not include WPC-S and WPC-95.
• Jerry Clause, who provided tons of tips and tricks.
• Mr. Johnson and his web site at www.aros.net/~rayj/action/tech. Ray's postings and tips were most helpful.
• Jonathan Deitch's advice, tips and tricks.
• Duncan Brown. Duncan provided lots of tips and tricks.
• Rob Hayes, who's advice and proof reading were very appreciated.
• David Gersic, who also did proof reading and provided some tips.
• Bill Ung for his excellent knowledge of this system.
• Pin Lizard and their very informational web page at pbliz.com.
• John Sladek for some great tips and tricks.
• John Robertson and his posts & tips helped mucho grande.

Why is this Document Available?
When I was first started fixing pinballs, I was amazed at the lack of any books. So when I fixed things I wrote them down. This is a cumulation of all those notes. The best book I found on WPC and System 11 was Norbert Snicer's Pinball Machines: How they Work & Troubleshooting, 1992. An excellent book which I highly recommend. Unfortunately, it doesn't cover the newer WPC-S and WPC-95 systems, as it was published in 1992.