Someone touching this game and the one beside it got a real shock, and tens of volts AC can be measured between the lockdown bars of neighbouring games.

Shock or voltage between cabinets: check line cord polarity to the fuse

Cause: The line cord colours did not match the schematic: the cord's hot and neutral wires were swapped where they joined the game wiring, so the main fuse was on the neutral side instead of the hot side.

Checks

• With the game unplugged, follow the line cord into the cabinet and compare each wire against the schematic's colours.
• Hot must go through the main fuse (and power switch) before the transformer; check this with a meter between ground and the fuse holder with the game plugged in and switched off.
• Check that the cord's ground wire is bonded to the transformer frame, and check the wall outlets for reversed wiring.

Fix

• Rewire the cord so hot goes to the fuse and neutral to the transformer side, with the ground bonded to the metal frame.

Line voltage: unplug the game before working on the cord or power wiring, and treat any measurable voltage on metal parts as a hazard until it is found.

Systems

• Electro-mechanical

Games

• Doodle Bug

Related tips

• Shock from Gottlieb coin door coin switches
• Shock from the start button or coin door

Source: Pinball Repair help group!! (Facebook group)