The other day I was working on a game and traced the problem back to a blown bridge rectifier, so I thought it might be nice to produce a short little video on how to test/check bridge rectifiers in pinball machines, as well as a little info on what they do.
In this short video, I go over how to test the coin door service switches, and if faulty, how to replace them.
This is a fairly simple procedure.
If you have a button in the coin door that doesn’t appear to work, the first thing you should do is check to see if any of the wires have broken off or there’s a bad solder joint. This is very common because the coin door is opened and closed quite a lot and things can get snagged on the wires. Always check the wiring to make sure there are no kinks or damage to the wire. In the video I use a multimeter set to continuity to test the integrity of the switches. If the switches seem to work and the wiring is intact, the next thing to check is the continuity between the switches and the connector on the MPU board. If all that checks out, it could be one of the chips on the MPU board that handles the cabinet switches.