Just put it on location. Owner says the ball kicks out to the shooter lane but occasionally the launch button will not send the ball up. He said he hits the side of the cabinet and that solves the problem. I tested the shooter lane switch in switch test thoroughly and it seems to work perfectly. I also played a bunch of games and it never happened to me of course. Diode and wires on that switch all look and feel attached well.
What else should I be looking at? Possible switch matrix issue? I was not thinking so since all my test games all seemed to work just fine.