Switch test shows no active switches even with all the balls in the trough; the drop target and shooter lane switches on the same column are dead too.
Trough and other switches on one column read open: broken column wire at the trough
Cause: The column drive wire (green-red) had broken where it daisy-chains through the upper trough switches.
Checks
- Unplug the switch connectors at the CPU board and use a jumper from the column pin to each row pin in switch test; if every switch registers, the board is good and the fault is in the playfield wiring.
- Follow the column wire from switch to switch along the daisy chain, and check the IDC connectors.
Fix
- Repair the broken column wire, then adjust the lock and trough switches so they register reliably.
Systems
Games
Related tips
- Balrog twitches and multiball hole switch is dead: wire off the switch
- Midway eject switch falsely triggers when a ball is locked: shooter switch wiring
Source: Pinball Repair help group!! (Facebook group)