Are the "SUPERSONIC" spell-name lights actually the bonus count? If so, does the bonus actually count down to zero, and get added to the player score correctly each time the ball drains?

If "SUPERSONIC" is the bonus count, then it kind of sounds to me like there's some fault happening with the interaction of the bonus unit count-down and the triggering of the game over relay via the outhole relay.

My initial thought is that it has something to do with one of the wipers on the ball count unit, in particular the rivet and wiper shown at 8-D on the schematic (the lower one of the two with rivets marked 5 - 4 - 3 - 2 - 1 - 0). My thinking is that rivet 1 may not be making good contact, but this is just a guess.

If that isn't it, then some more details on the behavior of the fault might help to narrow down its possible source.

- TimMe