Quoted from TimC:Another thing I should mention, when it started failing it would say finish ball 2, but when it kicked ball 3 the backboard would go off "2" but not light "3". I'd turn it off and on, start a new game and it would work fine. Then after this happening a few times, one time I started a game and it just started racking up points without even plunging. Turned the machine off and back on, and that's when it stopped resetting entirely.
That sounds like a playfield switch is making contact when it should not be.