Reset or lock-up: which points where
A lock-up is when the game freezes with both CPU board LEDs on (System 7 shows "0" on its LED display). Resets during play usually point to power: a coil diode, the +5 V filter capacitor or the switch matrix. Lock-ups in play or attract mode usually point to connectors. Resets in attract mode point to connectors or line voltage below about 115 V.
Systems
Related tips
- System 3 CPU board reset circuit modification
- Random lockups from the 12 V logic pin
- Game keeps resetting: replace the 5101 RAM (an NVRAM works)
- CPU never starts: check the reset line at IC1 pin 40
- Intermittent lockups with both CPU LEDs on
- Free play won't take on System 7: do a factory reset first
- Game only boots after several power cycles: corrosion under the 6808 CPU socket
- "Adjust Failure" at power-on
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)