The solenoid fuse (F2) blows at the first power-up and solenoids fire on their own; lamps and blanking may also misbehave.

Solenoid fuse blows at power-on and solenoids fire: driver board logic chips

Cause: Failed logic chips on the driver board. On this board the switch-matrix section chips (IC15 to IC18) were making the solenoids fire, and IC14 (lamp column and blanking) was also bad.

Checks

• Rule out wiring and coils first: measure coil resistances and unplug the solenoid connectors to see if F2 still blows.
• Swap in a known good driver board; if the game then works, the fault is on the original driver board.

Fix

• Socket and replace the bad logic chips on the driver board (here IC14 to IC18), and socket the PIAs while there.

Systems

• Williams System 4

Games

• Flash

Related tips

• Slings and pops all burned at once: CPU lock-up from the 40-pin interconnect
• Solenoid fuse blows at power-on: frayed 28 V wire touching ground under the playfield
• Coil has power and wiring is good but still dead or locked on
• Add a blanking LED to a driver board
• Spare transistors for driver board and power supply
• Test a TIP120/TIP102 solenoid driver with a meter
• Burnt 27 ohm lamp matrix resistors R149-R156 on the driver board
• Use the tester LED, not a logic probe, for driver board tests

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