Having a little trouble with my CE3k (SS version).

Issue the Roto target, fires but does not release. The plunger is magnetically stuck, until power is turned off

The Roto target coil is fired by the under PF transistor (2N5875 PNP). This transistor is connected to the Lamp/Solenoid driver board. And the Lamp/Solenoid driver board is controlled by a Ni-Wumpf CPU board.

I have had this Machine for 5 years and this is a new issue.

What I think is happening the under PF transistor is not shutting off completely after firing the roto target coil. I can manually pull the plunger down, but the return spring can’t after coil firing. If I turn off the power to the machine, then the return spring pulls the plunger down and locks the Roto target in position.
So far I have tried adding more power to the spring by way of a 2nd spring, no change. I have also tried a clamping (Pull Up) 5KΩ resistor from Base to Emitter, no change.

I guess I’m asking if it is a problem with the under PF transistor or an issue on the driver board. Best way to determine this and best fix.

Note - when I 1st start the machine from "COLD", the issue doesn't happen for the 1st ball or so.
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Thank, I did try both base to emitter and base to collector. Must have got it wrong which did what, ether way it did not fix my issue. I will edit my OP, Thanks.

You are right on the money, just replaced the transistor in the red ring (Picture Below), looks like I'm not the 1st to do a repair here.
Anyway replaced with a TIP102, CE3K is running again.
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