Tweaking all the little bugs out of a Bally Space Invaders pinball. Newest quirk, seems to be randomly advancing to next ball mid play. Can't find another example of such in the forum but I am new here and still learning the search skills for this forum. Anyone seen this before? Doesn't seem to be associated with any particular action going on during play. If playing one player, goes to next ball. If playing multiple players, goes to next player when this error rears its ugly head. Honestly at a loss on even where to begin on this.

Thx slochar. Will try those suggestions. New to pinball repair and gotta admit, laughed when you suggested pounding on the playfield. Some repair techniques are universal. Can't figure out what's wrong with it? Hit the SOB ! My first car was a '76 Firebird. I think I had more dents inside the engine compartment than I did in the body!

Many thx slochar! Was indeed the outhole switch. I can see there is definitely a learning curve in pinball ownership! Firearms, woodworking, and now pinball. I don't dare retire. The hobby workload will kill me !