Quoted from robertmee:

Sounds like your coil shorted. Replace it.

Quoted from robertmee:

Good deal....Figures Stern's diagram is wrong. The Diagram shows Q14, but I see from the chart in the manual it's Q12. Not only that, they got the connector wrong too...J8 vs J9. Hard to know what to believe without standing in front of the game.
Anyway, glad you got it figured out.[quoted image]

Quoted from robertmee:

You want to be careful, and not apply high heat to the pads for very long. Do you have a decent soldering iron that's temperature controlled or just a 15W pencil heater? Definitely don't use a solder gun as they're too hot. For desoldering, clip the transistor off the board so you're dealing with only one leg at a time. If you're unsure of proper desolder and re-solder techniques, best to get a friend to do it that is, or practice on an old board first.

Quoted from robertmee:

On a Stern ST? I don't think flipper coils have diodes on them. They're on the board aren't they? Admittedly, never owned a ST, but just going by the Stern Manual. But yeah, he can check it on the board. However, in another thread, he mentioned that held the flipper up for about 3 minutes to show someone something, and that likely blew the transistor.

Quoted from robertmee:

Yeah, we get that....but your post said tied to the coil, which isn't the case...diodes are on the board. That's all I was clarifying.

Quoted from robertmee:

Ed is correct that it doesn't hurt to check the diode....I think it's D12...it'll be right near the Q12 transistor. Remove the J connector for the coil and with power off, Meter on diode, you should see .6v with meter leads one way and open or OL with leads reversed across diode.