Sounds like a shorted-on transistor.

The controlling transistor for that flipper. Should be on the Fliptronics board I believe.

Coin door open, voltage cut to coils so a fried transistor isn't completing a circuit to the flipper coil. Closed, it immediately has a complete path and flipper activates. New transistor should fix the problem.

It should be on the big row of transistors on the fliptronic board, easy to see them, measure them up until you find a bad one, then simply unsolder that one and switch it a new one of equal value.

I have done it with a simple unsolder tool so it shouldnt be a problem.

Also, dont drink and repair

Yeah -- no reason to buy a whole board. You can clip the 3 legs then take each out individually by holding with pliers and heating up. Prob will need some desolder braid to get the holes clean so new legs all slide thru

If a coil was fried, you would notice. Does the coil look or smell burnt? And are you sure that you replaced the right transistors per the board schematic, and that all three legs on each transistor you did replace have good contact and no broken or cracked solder joints? Check to make sure you have no contact with surrounding wires, light sockets or switches that could be tripping it also. I was fixing my Stern Dracula last night, and every time I engaged the left sling the upper-most right drop targets would pop up. A light socket in the vicinity was touching a diode and another wire...weird.