I have a bally corvette with a flipper issue.

I bought the game from a lady who had a tech over to attempt to fix the upper left flipper. This tech put in a new fliptronics board and totally rebuilt all 3 flippers, including the coils. When I got it the upper left flipper was dead. Fuse was blown on the fliptronics board.

Here's what I did:
1)Replaced both diodes on the coil
2)Moved the end of stroke switch out further (it was preventing a full flip from the coil)
3)Replaced the fuse
4) Replaced every ribbon cable.

At this point the flipper now worked but with the glass off I could hear what sounded like a pulsing/electrical sound). Coil was getting warm to the touch.

I then pulled the entire flipper apart to make sure nothing was mechanically binding. It wasn't. I also swapped the opto boards from left flipper to right flipper.
No change.

Where do I go from here?

Swapped fliptronics boards. No change.