The backbox Rocky pop-up never fires in play or solenoid test, while the lion and rhino work. A new coil changed nothing, and both coil lugs show about 43 V.
Rocky pop-up in the backbox won't fire, even with a new coil: bad driver Q41
Cause: The driver transistor (Q41) for that coil had failed.
Checks
- In solenoid test, check whether the coil's drive wire at the board connector is pulled to ground; if not, the driver isn't switching.
- Briefly ground the drive wire: if the coil fires, the wiring and coil are good.
- Compare the transistor in diode mode with its neighbours.
Fix
- Replace Q41 with the correct part for your board (the replacement board here used a MOSFET, not a TIP122), and look for whatever shorted it.
Systems
Games
Related tips
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Source: Pinball Repair help group!! (Facebook group)