Repair battery corrosion before chasing MPU flash codes
Corrosion causes intermittent faults that make flash-code diagnosis unreliable. Remove the battery and neutralise and repair any corroded area of the MPU (described in part one of this guide) before working through the LED codes.
Systems
Related tips
- Repairing battery corrosion on the MPU
- Corrosion under MPU J4 can destroy every chip
- Cut the original MPU battery off right away
- Bally-35 MPU: remove the on-board rechargeable battery before it leaks
- Reset section parts typically ruined by battery corrosion
- Switch faults from corrosion under MPU J2 or J3
- Sometimes three flashes, sometimes seven, with flickering scores
- Fitting a remote AA battery pack
Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Two, Clay Harrell (pinrepair.com)