Jerad S Salem , IA January 03, 2015 Appliance: Whirlpool Microwave Oven MH1170XSQ0 Microwave wouldn't heat when you took item out after beep it was still cold! all other functions were fine Removed unit from wall and took outer shell off, de-energized capacitor and then took a multi-meter and tested all the High voltage parts and magnetron. They tested out fine other than the diode and then I looked at the "Safety" circuit if you will the power loop that goes through door switches and thermostats to energize the High Voltage transformer and magnetron. Turns out the thermostat that is on the side of the magnetron wasn't closed, so I took a butane torch and heated it up past the upper limit to get it to open. Next, I checked it with the meter and then let it cool down to where it should have closed again and it would make intermittently. So I got on appliance pros and researched the parts, the way the parts list is broken down is easy to trace out what you need! I have used their website for several repairs from dishwashers to dryers and fridge and have had good luck with new parts and returns when needed! Excellent place to get parts. Read More... 2 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes Tools: Screwdrivers