Opening the coin door (for example to change the volume) makes the game restart and act glitchy for a short while.

Game restarts when the coin door is opened: slam switch out of adjustment

Cause: The coin door slam tilt switch was out of adjustment and was being closed when the door moved.

Checks

• Try to reproduce it by opening and closing the door slowly.
• Look at the slam switch on the door and check its gap.

Fix

• Re-gap the slam tilt switch so that opening the door does not close it.

Systems

• Williams System 11C

Games

• Bad Cats

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