All coil lugs have voltage but the flipper does not work.
Power at the flipper coil but no flip
Cause: An EOS switch open or dirty at rest, a broken EOS wire, a dirty cabinet switch, a bad backbox-to-cabinet connector, or a fault in the ground return to the driver board.
Checks
- At rest the EOS contacts should touch and be clean.
- Re-seat the medium white backbox/cabinet connector with the thick orange wires; if that cures it, re-pin the connector.
- Check driver board connector 2J12 pins 1 and 2 (the bottom two pins of the second plug down on the board's left side), which carry the orange flipper ground wires to the relay.
- If one flipper works and one does not, the relay driver is fine and 2J12 is the likely culprit.
Fix
- Resolder or re-crimp 2J12 pins, repair a cracked trace, or replace the relay or its driver.
Systems
Related tips
- Flipper relay does not click on in test
- Flippers dead, or still live after game over: the flipper relay
- Firepower right flipper switches sit close to the pawl: a short kills the switch matrix
- Flippers dead, flipper relay only buzzes faintly: replace the relay's diode D1
- All coils or lamps lock on at power-up
- One or a few coils lock on at power-up
- Nearly every coil energizes at power-on
- Whole game dead after working on a flipper EOS switch
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)