Mandeville, LA
Ok, I'm in the final stages of getting my Silverball Mania back together and today I needed to do some soldering with the playfield propped up. So, I grab my (metal) power strip and lean over the cabinet to place it in there for my soldering iron. I notice a slight tingle almost like a scratching from the side rails. I run my finger over it and sure enough, there's a tickle of voltage there. My Fluke tells me it's a bit more than a tickle... ~63VAC.
I had forgotten that I left the machine plugged in to do this and the voltage can only be felt while I'm touching the metal power strip and some Silverball Mania metal. The plug has the ground prong cut off and will obviously need to be replaced ASAP. Makes me wonder if I've discovered some sort of short / ground problem that warrants further investigation.
See attached for the incoming AC and associated schematic. It looks like the ground braid is tied to the chassis of FL1 and between the capacitors separating L and N and (should be) grounded at the receptacle. Is it possible that one of the caps in FL1 has shorted or partially shorted and is now essentially putting L (line voltage) onto the ground braid and all of the metal components in my cabinet? With the plug pulled, I get an open circuit across the varistor, an open circuit between L and braid and an open circuit between N and braid. Not sure, however what resistance a failed cap would present to a DMM. I haven't opened FL1 up yet.
Thoughts?
I've got some other strange problems with some feature lamps that I'll need to address after I get this thing grounded properly. The manual pretty much says "replace the lamp board." If that doesn't fix it, "replace the MPU". One thing at a time.
