Wiring up a Nintendo cabinet for Mario Bros. and the existing harness was for a Vs. system and didn't include a -5v wire from the power supply to the PCB.
Yeah, I saw it on the pinouts but I couldn't find a schematic to see if it's really needed. I'll just add the wire tomorrow... the daughter helped me re-wire the Vs. cabinet today so she'll be happy there's a little more to do then.