Solenoid fuse F2 blows, or the coin door buzzes loudly.
Solenoid fuse blows: check the coin lockout coil
Cause: The always-on coin lockout coil overheats with age, its windings short together and its resistance falls from about 80 ohms; below about 2.5 ohms it is effectively a dead short.
Checks
- Unplug driver board connector J9 to isolate the coil and measure across its lugs: it should be over 50 ohms.
- Test driver transistor Q45 in the solenoid test (coil 16) or with a meter on diode test.
Fix
- Replace the coil, or disconnect it by cutting its ground wire to the driver board and bending or removing the coin mech trigger bar so coins pass without it.
Systems
Related tips
- Solenoid fuse blows at power-on: frayed 28 V wire touching ground under the playfield
- Bring a repaired board set back into the game
- Coils 9-15 and coin lockout: connector, transistors, PIA pin
- Pop bumper or slingshot locked on
- Kicker coil locks on again after a new TIP122: dead 7408 gate on the driver board
- Solenoid fuse blows as soon as the game is turned on
- Solenoid fuse blows at power-on and solenoids fire: driver board logic chips
- Damage after the black and white plugs were swapped
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)