One drop target bank never resets, even in solenoid test, while the other bank on the same fuse works. The coil fires when its lug or its driver transistor is grounded, and the transistor tests good.
Drop target bank won't reset though it fires when grounded: reseat driver board plugs
Cause: A poor connection at the driver board connectors, a very common System 80 problem.
Checks
- With the game on, measure DC volts from the coil lug to ground to confirm power reaches the coil.
- Ground the driver transistor briefly to prove the coil and wiring.
- Reseat the CPU-to-driver harness and every driver board connector several times.
Fix
- Reseat all connectors on the driver board (repin any with worn or tarnished pins).
Systems
Games
Related tips
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- Connector parts usually needed to repin one System 80 game
- How Gottlieb numbers double-sided connector pins
- Drop bank reset coil dead everywhere: driver ground wire moved to the wrong J4 pin
- Coils lock on and burn because of the Gottlieb ground fault
Source: Pinball Repair help group!! (Facebook group)