A bank of lamps and several solenoids (the plunger, the ball popper, or the trough eject so no ball is served) stop working or come and go, while fuses and coils check out.

Several solenoids and a lamp group dead: reseat the CPU-to-driver ribbon

Cause: A poor connection at the ribbon cable between the CPU board and the power driver board.

Checks

• Before chasing individual coils, unplug and refit the CPU-to-driver ribbon at both ends and check its pin 1 orientation.

Fix

• Reseat (or replace) the ribbon cable.

Systems

• WPC Dot Matrix

Games

• Terminator 2: Judgment Day

Related tips

• Launch coil locks on and blows its transistor and fuse every time it is tested
• Resets from worn power connectors between transformer, driver and CPU boards
• Lamp matrix connectors on the driver board
• One switch triggers others and flippers act oddly: drop target switch wired backwards
• Reseat the ribbon cables before chasing odd behavior
• GI string dead with a scorched connector
• GI out because the GI connector burned
• GI connectors on the driver board

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