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.
Category: Board Repair
Issue: Client reports no 5VDC. Attempted to replace voltage regulator (U191), not completely installed. Fix: Removed U191, cleaned pins, and removed damaged pads. Re-installed U191 with jumpers where pads were removed, TP4 = 5.1VDC. Board passed general test (controlled lamps, solenoids, flashers, and GI).
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.
Issue: Client reports switch errors and solenoid issues. Diagnosis confirms bad special solenoid channels, bad switch input and control outputs. Fix: Replace Q11 and Q12 with IRL530N.