Quoted from AdjustFailure:
My Evel Knievel has had this problem for years - if you "nail" the center stand up target with a hard direct hit, the ball bounces off but does not register a hit. However if it is hit by the ball a bit less directly, a bit softer or at an angle, it always registers the hit with chimes and scoring. I have cleaned and adjusted the switch behind the target but still no change. I am now thinking it is something else, on the boards or the electronics that are the problem. Anyone have any ideas how to diagnose where the problem is that prevents recognizing a fast/hard/direct hit ?
Either the small ceramic capacitor on that switch is missing, or has failed. The capacitor is there to stretch the pulse produced by the switch closure, meaning even with a very hard/direct hit it will still get picked up.