The F4 43 V fuse on the rectifier board blows as soon as the game is switched on. Swapping in known good boards and unplugging the playfield change nothing, but the fuse holds when J4 on the lamp driver board is unplugged.
43 V solenoid fuse blows at power-on only with the lamp board plugged in
Cause: After the backbox connectors were rebuilt, one pin in rectifier board connector J3 sat one slot over. That put about 46 V onto a line the lamp driver board uses as a ground return.
Checks
- Unplug connectors one at a time to find which one makes the fuse blow.
- Measure each pin of the suspect connector against ground with the game on; a ground or return pin showing solenoid voltage points to a misplaced wire.
- Check every pin position in the rebuilt connectors against the manual's wiring chart.
Fix
- Move the misplaced pin to its correct slot.
Measuring live connectors in the backbox: keep one hand away and watch for the high-voltage display supply.
Systems
Games
Related tips
- F3, F4 or F5 blows on the rectifier board
- F4 still blows with the playfield coils out of circuit
- Fuse blows when the spinning wheel motor is connected: cut the expander jumper
- Main solenoid fuse F4 blows (hard short)
- Solenoid fuse blows as soon as a swapped expander board is fitted
- Rectifier board and playfield fuse ratings
- Find the coil that keeps blowing the playfield fuse
- Playfield coil fuse blows at power-up: shorted outhole kicker coil
Source: Pinball Repair help group!! (Facebook group)