Is the solenoid not individually fused? Most are on gottliebs... Are you sure the coil is ever actually locking on? If it's not locking in the fuse won't help
I've got the same issue on my BH. Brand new coil, EOS mod, still blows transistors occasionally. I assume it's just too narrowly rated and the coil is slowly killing it. Think I might just mod in a relay driven by the board and be done with it.