Quoted from Danovh:MarkG, yes it has worked before but just started this issue. It only happens when there is a bonus lit, so if no combination of drops are made making a bonus lit, the bonus ladder doesn't go though it's sequence & the game advances to the next ball. If any drop combination is made & a bonus light is lit, it goes though it's sequence lighting the arrows from 1000 to 5000 scoring the lit drop combination, then starts over @ 1000 to 5000 again and keeps repeating & doesn't advance to next ball.
isnt there a stepper for the bonus? Check the solenoid that resets the bank, if the bank doesnt reset I think you'll end up with this issue. So either bank fuse or the contact that drives the reset is dirty... 120v reset i believe