Scope.
This document is a repair guide for Williams System 11 pinball games made from 1986 (High Speed) to 1990 (Dr.Dude). Some Bally games from 1988 to 1990 are also included as Williams bought the Bally pinball name in 1988. 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, part two, and part three). The basis of this document came from the WPC Repair guide. These two systems are very similar in design.

IMPORTANT: Before you Start!
IF YOU HAVE NO EXPERIENCE IN CIRCUIT BOARD REPAIR, YOU SHOULD NOT TRY AND 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") by you.

If you aren't up to repairing your circuit boards yourself, I highly recommend Tom Callahan or John Robertson (in Canada). Note these repair facilities will NOT repair your circuit board after it has been unsuccessfully repaired by you.

Table of Contents

1. Getting Started:
1. Experience, Schematics
2. Necessary Tools
3. Parts to have On-Hand
4. Different System Generations
5. Game List
6. The Circuit Boards and How they Work

2. Before Turning the Game On:

1. Check the Fuses
2. Burnt GI Connectors
3. Quick and Dirty Transistor Testing
4. Should I leave my Game Powered On?

3. When Things Don't Work:

1. Replacing Components
2. Checking Transistors/Coils (locked on coils)
3. Game Resets (Diodes) & Immediate Blowing Fuses (Bridge Rectifiers)
4. Power-On Tones and Sound Diagnostics/Problems
5. CPU LED Codes and Diagnostics
6. Fixing a Dead CPU
7. CPU Test EPROMs
8. Problems with Flippers
9. Flash Lamp Problems
10. The Lamp Matrix
11. The Switch Matrix
12. Infrared Optic Switches (Drop Target switches)
13. Score Display Problems
14. "Factory Setting" or "Adjustment Error" (Battery Problems)
15. Miscellaneous Oddities

4. Finishing Up:

1. Rebuilding Flippers

Thanks to...
Special thanks to the many who provided feedback on this document. This includes Jonathan Deitch, Tom Cahill at Williams , Jerry Clause, and many others.

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.