So this spooky I am working on had the front cabinet and coin door wiring all mutilated. Before doing anything the start (credit in schematics) button was acting as the test return switch. I completely disconnected the test switch and it was still acting the same way.

After wiring things mostly back up correctly no change. Finally I hooked up the 2 tilt 2 switches on row 0 and now none of the switches work at all.

I have cn11 for all the other switches disconnected while I try to isolate the problem.

I dont have my oscilloscope here and I dont really want to lug it down here as it is very old and gigantic. Can I just hook up 5v to each of column wires with the connector removed to try and figure out where the wiring issue is? Is 5v too much for the 1n4148 diodes? Or am I going about this all wrong?