re: Need help with my microwave

I just replaced my Samsung microwave with the exact same symptoms. Mine was under warranty so had a covered house call by a repair tech. Turns out it was shorting to the chassis intermittently. Tech declared it unrepairable and a fire hazard. Got a new Whirlpool (based on his recommendation of what he sees for reliability) and problem never resurfaced.

So yeah, just go get another one. Even if you figure out how to remove the panel(s) and sub-chassis, that may not tell you anything and by the time you screw around with it for a few hours you could have a new one in place.