I just replaced with another 2 1/2 amp sb fuse and it seems to play fine. I do hear a clicking noise though from time to time around the driver & power supply boards. Is this normal? I don't recall hearing it before.
If you've blown several fuses, something is wrong. Throwing more fuses at it isn't going to make it go away.
Check the resistance across all solenoids. also check for any exposed wires nearby that could be shorting against the solenoids. It's also possible for a loose coil winding to have sneaked around the side and short against the coil stop when it fires.
Easiest way to isolate what solenoid is the culprit is to put it in solenoid test and let it run until the fuse blows.