am i missing something or is there a diode missing from the switch or is it on a tag else where? 

The board has had 2 New PIA chips fitted

There's currently no diode on the micro switch. Is there suppose to be? I'm unsure as this is a reasonably new game to me but there wasn't one when I brought it. I'm sure the problem is with the switch on the ball release but I have no idea about the exit chamber kick out.