Quoted from aKa:
...Anyways, there's two coils that are briefly energised during the beeping initialising sequence when I turn on the table. Is it normal or indicative of a problem with these two coils (the big target bank one and the loop drop target one) ? Can it be the cause of the under-playfield fuse blowing ?
On the 3rd beep of the last 5 sequence the loop drop solenoid fires, and then on the last beep I hear another energize, but not sure which one. The drop targets, big target bank reset, does NOT reset during the initialization... that happens after starting a game, so you may have a short between two drivers.
Get the test mode working and it should be easy to confirm that.