Williams System 11B CPU Board

Issue: No background music.

Fix: U42 (music control PIA) outputs test OK with Leon ROM but corrosion in area. Remove U41/42 PIAs, clean corrosion, and add sockets. No continuity from U42-16/17 to SRC3, fixed. Install new U41/42 PIAs. Remove U37 (LS138), clean corrosion, and add socket. Install new U37 chip.

Williams WPC Driver Board

Issue: Client reports game resetting. Bench test of drive board shows the following voltages, all of which are OK.

  • TP1 = 12.6VDC
  • TP2 = 5VDC
  • TP3 = 12VDC
  • TP8 = 19.3VDC

Fix: Suspect bad grounding connection in game (screws, connectors, etc.) – replaced BR2, C5, and Q1 (with improved ground connection) anyways.

Williams Theater of Magic

Issue1: Settings reset, corroded batteries.

Fix1: Replaced battery holder and batteries.

Issue2: Diagnostic switches not working.

Fix2: Cleaned switches with rubbing alcohol.

Issue3: Trunk hits not registering.

Fix3: Adjusted eddy current sensor under playfield.

Issue4: Trunk shot not registering jackpots.

Fix4: Adjust subway microswitch.