Closing some playfield switches fires solenoids they shouldn't, and switches in some columns register as other switches. The game had worked before being stored.

Playfield switches fire coils and switch columns misread: failed column driver Q44

Cause: A failed switch column driver transistor (Q44) on the CPU board, plus a broken diode joint on a switch.

Checks

• In switch test, close switches one at a time by hand and note which other switches appear.
• Unplug the playfield switch connectors and probe the column drive pins with a logic probe: each should pulse; one that is stuck or missing points at its driver transistor.
• Check the diodes on the affected switches, and look for any wires added by earlier repairs.

Fix

• Replace the faulty column driver transistor and resolder the broken switch diode.

Systems

• Williams System 11B

Games

• Cyclone

Related tips

• Switch matrix dead after an under-playfield adjustment with power on
• Row or column error: CPU board or playfield?
• Testing the switch columns with a clip lead
• Connector 1J8 switch column pins
• Decide whether a phantom switch is in the playfield or the CPU board
• Coin door test buttons and special solenoid switches are outside the matrix
• Fixing a dead switch column on the CPU board
• A whole switch row or column is dead

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