Quoted from LTG:
You bang on the playfield to see if vibration is setting any off ?
LTG : )
Problem is that I cannot reproduce the problem, happens from time to time. I don‘t think that banging will be successful, because the shaker is working the time producing enough vibrations. Nevertheless, thank you for your comment.
Quoted from EaglePin:
Might not be a bad switch but it could be an opto or another switch that's out of alignment so it's continually registering. Did you try going into the switch test menu to see if any switch is registering when it shouldn't be?
I have looked for a red marked switch as bad switch. How can I see in the switch test that a switch is registering when it should not? Thanks to you as well.