Tie the 80/80A power supply logic ground to its heat sink plate
As part of the Gottlieb ground fix, the board's logic ground should be bonded to the metal heat sink plate, which is later wired straight to ground.
Systems
Related tips
- Reassemble and set up the 80/80A power supply
- Bench-test an 80/80A power supply in the game, part 1
- Bench-test an 80/80A power supply in the game, part 2
- Parts for the 80/80A power supply rebuild
- Mandatory 80/80A power supply rebuild
- Recommended extras for the 80/80A power supply
- Test and remove the 80/80A power supply's big transistor
- 80/80A power supply has 12 V but no +5 V
Source: Repairing & Upgrading Gottlieb System 80 Pinballs from 1980 to 1989, Part One, Clay Harrell (pinrepair.com)