Quoted from yonkiman:We also had a problem when something loose on/near the flipper assembly broke the hold coil wiring (Cary can add details and/or tell me I've got it all wrong).
Problem: Coil Hold went out
Symptom: Flipper would go up and drop back down
Solution: Damned silly. One screw fell out of the plate that holds the flipper return spring, and the other screw was mad loose. Ultimately the plate, during flipper action, smacked into the coil, cut through coil wrap, nailed the coil wiring, cut one of the coil wires in half and killed the hold power.
Moral of this story: Make sure stuff is tight. Not the only loose bits I've found in the game, but this one causes some damage!