After replacing a frayed two-prong cord with a grounded three-wire cord, plugging the game in trips the GFCI outlet immediately.
New line cord trips the GFCI at once: cord conductors joined to the wrong game wires
Cause: The new cord's ground conductor had been joined to a game wire that carries line power (the wire that runs to the power switch), instead of only to the cabinet ground point.
Checks
- Unplug the game and identify each game-side wire with the schematic: the wire to the power switch and fuse is the hot side, the other line wire goes to the transformer, and ground goes only to the cabinet ground point and transformer frame.
- On a flat cord, check which outer conductor is hot and which is neutral before joining them.
Fix
- Rewire the cord: hot to the switch and fuse wire, neutral to the other transformer line wire, and the ground conductor only to the cabinet ground. Then check the transformer output voltages.
Line voltage: unplug the game before touching the cord or power wiring.
Systems
Games
Related tips
Source: Pinball Repair help group!! (Facebook group)