I'm guessing this will be a faulty node board if you have a KISS (Pro) If it's possible to swap the flipper buttons and see if the problem moves that might be worth trying. I can't tell from the manual what sort of configuration the buttons and boards have.

Do you have a schematic? The Stern manuals online don't have them anymore.

The point of swapping buttons was to eliminate the switch as a source of the problem. If you somehow swapped only the button and not the switch that activates the flipper then it could be your switch acting up. But since it works in test I think that's unlikely.

I still think it's a board problem. Without schematics I can't suggest where. I can't think of a component failure that would cause it to flip four times, then die.

He's saying check the resistance on both the hold winding and the high power winding. It should be close to the one you're not having a problem with. If you're lucky, the resistance is good but one of the solder joints is cracked.

Good luck.