Quote Originally Posted by Javier
they are in parallel, so four of them are 56 amps, blower can not be that much.

Also doubt the mosfets are fried, would check soldering points as suggested. The must probable status a blown mosfet will end in a circuit like this one is short-circuited, so blower symptom for burnt mosfets would be running at max speed allowed by the progressive control (not max stage).

Javier
if the mosfets were cooked would you not be able to pick up a burnt smell and see discolouration on the circuit board surrounding them? i don't have either of these so maybe it is just a case of bad soldering although they all appear to be ok. i dunno!