System 6 and 7: coin door must be open to change settings
System 6 added a memory protection circuit tied to a coin door switch, so adjustments and audits can only be changed, and the quick power-cycle out of audit mode only works, with the coin door open.
Systems
Related tips
- System 6 CPU board changes and ROM layout
- Identifying a System 3 to 7 CPU board
- What changed on the System 6A CPU board
- System 6 CPU board test points
- System 7 CPU board test points
- Which System 3 to 7 games use which flipper ROM system
- System 6 CPU board jumpers J1 to J6
- A System 7 CPU board can run any System 3 to 7 game
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Two, Clay Harrell (pinrepair.com)