I just remembered another issue I had with my Pioneer and while probably not the worst hack, it was certainly dangerous.
At some stage while I was working on it, it was plugged in, but off at the cabinet switch (which in hindsight wasn't a grand idea, but we've probably all done it at some point). I bumped against the drop target reset coil. *Buzzt* It bit me with some 240v fun. Promptly unplugged it, reset the house breaker so the lights came back on and then went hunting with DMM to figure out what was wrong, testing everything I could find in the schematic around those drop target coils.
power (resized).png
So the culprit is in this picture, though I didn't know at the time I took it, so it's not the greatest shot.
3429967801_20601f1276 Transformer and two coin counter relay_O (resized).jpg
It all looks ok, doesn't it? That is until you remember that until sometime around 1980, AC wiring in Australia used red for active, black for neutral and green for earth. USA uses black for active, and there's a bunch of white and red wires on the neutral side of the transformer... I eventually tested everything in the schematic, including the pins on the end of the line cord. I found that the earth pin (green) was ok, but the neutral pin on the plug (black) went to the main fuse and the active pin (red) went to what's intended to be the neutral side of the transformer. As the cabinet switch is STSP, only the neutral pin of the plug was switched, leaving the rest of the 240v circuits' active connected and oh so much fun to touch.
Given the line cord was 30+ years old I replaced it entirely with something that has the current, colour blind friendly, standard Australian AC colours - brown for active, blue for neutral and green/yellow stripe for earth.20170327_094748 (resized).jpg
I can't say for sure when the plug was wired in reverse, but the main board says "Australia 18" on it so I assume it was manufactured for export to Australia and that it had always been that the neutral was switched. Certainly the old line cord looked original and it was probably a good idea to replace it anyway - the insulation inside the white outer was pretty degraded. 20170327_101502 (resized).jpg