A correctly fitted backup capacitor or battery does not keep audits and high scores.
Memory capacitor or battery does not hold settings
Cause: The isolation diode CR26 (1N4148) has failed, so the backup tries to power the whole board when off.
Checks
- Diode-test CR26.
Fix
- Replace CR26 with a 1N4148.
Systems
Related tips
- Replacing the CPU battery with a remote AA pack
- Repairing battery corrosion on the CPU board
- Odd high scores usually mean a bad 5101 RAM
- Entering System 1 audits and tests
- DIP switch settings that make troubleshooting easier
- Swapped U4 or U5 spider still does not work
- Buck Rogers keeps adding 100s by itself
- High scores, replay levels or free play keep resetting
Source: Gottlieb System 1 Pinball Repair from 1977 to 1980, Clay Harrell (pinrepair.com)