So I have a TZ that is fully working except that it's blowing this fuse, and I cannot figure out why.

The fuse will blow on power-up of the machine immediately.

I've diagnosed that the fuse will blow only when the hot is soldered to the bottom left flipper coil (orange/blue). If I have the hold (blue/grey) and ground? (grey/yellow) attached, it doesn't blow - ONLY having the hot attached blows it.

What's confusing to me is that the manual says the f902 is dedicated to the upper left flipper. The upper left flipper works fine, and still works even after the fuse blows.

I've traced the wires back to the fliptronic board (which I replaced with a new rottendog one), and the wires trace correctly.

I've also tried replacing the coil.

What else could be causing this?

bueller?