It will be a coil. Could be any of them that were stuck on. You can isolate the area it is by disconnecting all of the jones plugs. If it does it when none are plugged in it's on the bottom board. Plug in the head or playfield, only one at a time and see when it blows a fuse. That should narrow down your search. Look for anything obvious, frozen coil plunger, fried looking coil, etc. good luck

It sounds like it's on the playfield. Either a short or bad coil. Even if all plungers move freely it can still be a bad coil. Did you disconnect the chime unit and the coin door?

Or does it have bells? either way disconnect those as well