I am working through a 4 MYBC I bought a couple of years ago and just now getting to shopping it. I have all features working with the exception of the zipper flippers closing. When I manually close them the 100 relay in the backbox energizes and stays energized. If I isolate the contact on the zipper stack under the playfield you can play the game without them trying to move. By isolating the switch on the zipper flipper stack I can play the game. If I move the switch and relay in the cabinet base for the zipper flippers to close, it locks in and energizes the 100 scoring reel and will not de energize. This also happens on all 4 players. The bell mounted to the side of the backbox also is energized and stays energized. I don't have a schematic and I am also schematic handicapped but am learning. Any help would be appreciated.