Some of these single player games didn't have a tilt relay. I believe this might be one of those models. A tilt would just trigger the Game Over relay. So this may be stuck in a Game Over state.
If you don't see a Tilt Relay and your are sure that none of your Tilt switches are the problem, I would check out that Game Over relay and make sure it is tripping and latching when the game is reset, and the switches on the Game Over relay are gapped correctly.