After moving the game, the left drop target bank stays down and the game acts as if the targets are constantly hit. A relay in the backbox clicks repeatedly while the targets are down, and the reset coil seems to work in test.

Drop target bank stays down while a backbox relay clicks: coil wires loose on the lugs

Cause: The wires on the reset coil's lugs had come loose, so the coil wasn't getting proper power in play. The clicking relay was the game repeatedly trying to reset the bank.

Checks

• Check in switch test that each target registers up and down.
• Inspect the reset coil's solder joints and tug each wire on the lugs.

Fix

• Resolder the wires to the reset coil lugs.

Systems

• Williams System 11C

Games

• Bad Cats

Related tips

• LED flashers blink when the flipper buttons are pressed
• Isolating the 50 V flasher circuits for LED flashers
• Whole groups of coils or all flashers dead: A/C select relay stuck
• Firing a coil by grounding its ground lug
• Which output drives the bank select relay
• A-bank coil not working
• Whole A or C bank of coils dead
• Later System 11 moved relay and diode boards to the backbox

Source: Pinball Repair help group!! (Facebook group)