Don't claim Genius status, but when my welder died, I checked the overheat switch, then searched for a fuse… Overheat switch checked out OK…No fuse to be found… finally found a burnt circuit on the circuit board...:bang head: Attempted to repair… and as soon as the machine was switched on
FIREWORKS!!! No replacement circuit board available… so I wound up buying a new machine… Hopefully you will track down a faulty switch or fuse...