Some or all GI strings are dead or flicker; the GI input connector on the driver board is brown or charred.

GI out because the GI connector burned

Cause: The GI input header (J115 on WPC-89/WPC-S, J103 on WPC-95) carries high current through small pins. Heat fatigues the solder joints, resistance rises, and the connector and board burn.

Checks

• With power off, inspect J115 (lower left of the driver board beside the five GI fuses), J120, J121 and J119 for discoloration.
• Check the back of the board for cracked or melted joints at those headers.

Fix

• Replace the board header pins as well as the plug housing and pins; repair any broken through-holes (see the related procedures).

Burnt connectors and pins can be hot enough to burn skin; power off and let the board cool before handling.

Systems

• WPC Alpha-Numeric
• WPC Dot Matrix
• WPC Fliptronics
• WPC DCS
• WPC-Security (WPC-S)
• WPC-95

Related tips

• GI connectors on the driver board
• GI string dead with a scorched connector
• Repair a burnt GI connector on the driver board
• Check the AC power input connectors too
• Lamp matrix connectors on the driver board
• Resets from worn power connectors between transformer, driver and CPU boards
• Backbox GI out while flashers work: burnt connectors at J120 and J121
• Burned power driver board traces at the header feeding AC to the Fliptronic board

Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part One, Clay Harrell (pinrepair.com)