After a restoration, the lower GI string stays out even with a known good power driver board. Moving the string's plug over by one pin lights it, and pulling its fuse makes it glow dim.

One GI string dead after a restoration: unkeyed J115 plugged in upside down

Cause: The GI transformer input connector J115 on the power driver board is not keyed and had been fitted upside down (by a previous owner), so the string's feed was on the wrong pins.

Checks

• Compare the wire colours on J115 with the manual's connector chart or a photo of a correct board.
• In GI test, press Start to show the connector, pins and fuse used by the dead string, and check for voltage there.

Fix

• Turn the J115 connector 180 degrees so the wires match the manual, then retest every GI string.
• Rewire or replace the connector if the pins were punched poorly, and add a key if it has none.

Unplug the game before moving GI connectors: they carry transformer AC.

Systems

• WPC Alpha-Numeric

Games

• The Machine: Bride of Pinbot

Related tips

• GI string dead after connector replacement: broken traces
• J115 GI input pin map (WPC-89/WPC-S driver board)
• GI will not dim or will not turn off
• Where GI power flows on the driver board
• A lamp row very bright or dead
• GI fuse keeps blowing: isolate driver board or wiring
• Lamp matrix faults with all lamp transistors good
• Test GI outputs on the driver board

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