Whirlpool Microwave WMH31017AS-2 not heating.... and I know why... just not sure how to fix, help pls! :)

[jasonh595]

hi & TIA for help/intel. I've read a bunch about microwaves, taken mine apart, tested components, etc over the last 24-48 hours and I'm stumped.

I have a Whirlpool WMH31017AS-2 (purchased in 2014) that won't heat. A few weeks ago my wife bought one of those splatter cover things with magnets, and didn't read the directions (ok I'll admit, I didn't either) which plead with you not to leave the cover attached to the top of the microwave while running. We used it properly (ie, covering food) a bunch of times, but a handful of times lazily left it attached to the top of the microwave while it was running... and now the thing runs but doesn't heat food. (Microwave had been operating normally until then.)

So in my research, I was prepared for it to be the magnetron... except that when I tested the magnetron with my digital multimeter it checked out fine. (And visually it looks ok too, not browned out or fried-looking.) Tested the diode which seems to be working as intended, and the capacitor as well. So.... any ideas? I tried figuring out what part of the microwave those magnets would mess with but haven't been able to find anything online.

Any insight is greatly appreciated so I can hopefully just replace the needed part and not the whole unit.

Thanks

[Vance R]

Best way for us to help you - put the microwave back together, setup to measure ampergae draw and run the microwave with a cup of water as a load. Let us know the amps the microwave draws while running.