I have a Black Knight in great shape that played perfectly for a long time. Now when I turn it on, the bell rings, a ball kicks into the trough, and the number 2500 appears in the P1 score area. If I shoot the ball, the flippers work and the bumpers bump, but when the ball drains, the game stops cold. Can't credit it or play any further. I have found if I cycle through the audit functions a time or two, it will reset to attract mode and can then be played like normal. The only problem with this is that all of the high scores are reset, and any settings are reset as well each time I do this. Ideas?