I struggled for a couple of weeks with this game. Here are a couple of tips. For the S&T board rebuild the connectors on the board, both the connectors on the board and the Molex connector in-line on the harness. Also, the ground plane sucks on this era of game. Bally used foil covered cardboard in the back box. Tie the board mounting brackets together and to door and the ground braid using wire and crimp connectors. These 2 things will fix numerous vexing problems.