How to Troubleshoot & Replace Samsung AP4580109 / DE47-20007B Microwave Thermostat

Unplugged unit, Tested all the thermostats after bleeding off any existing voltage. Found the thermostat at the top of microwave that rests against the ceiling of microwave had gotten a piece of food stuck to it and caused it to overheat. The contacts were melted. Cut wire, crimped on new leads, replaced thermostat and unit fired right back up. $5 fix. Took about 35-45 minutes to take microwave down, take off shroud and rewire and replace thermostat. 

The Thermal fuse (Thermostat) had blown during normal operation, making the microwave inoperative. Replacing the thermostat solved the immediate problem, though why the fuse blew in the first place is unknown. This is a convection microwave oven and the interior normally bets pretty high. I think this is a design problem, and purchased several of these thermal fuses, 

Replaced magnetron thermostat mounted directly over the magnetron (item 7-1 on drawing, Samsung PN DE47-20007B, AP Number AP4580109). Also replaced one of the electrical connectors to the thermostat (which had overheated) which a standard generic connector I had separately. 

Replaced two thermal cutouts inside built-in microwave oven. The most difficult part of the repair was uninstalling/re-installing the built-in unit and removing/replacing all the screws for the cover. Additionally, tracing down the open TCOs was a trick without any diagram. The TCO on the top of the cavity was easy, but this is the first time I've seen a TCO mounted on top of the mag (partially hidden), so I missed it the first go round. 

Simply looked up my make and model number bought all three fuses your site suggested and Wala sweet for $20 she is alive saved me hundreds of $$$$$ in repair/replace thank you... LOL 

Replaced a simple little thermostat cost less then $10.50. Cost thru Sears would have been close to $25.00. 

Appliance Parts Pros suggested a 99% chance of bad magnetron thermostat after I tested the fuse and it had continuity. I ordered the all 3 thermostats since it was already apart. 7 year old microwave works like new. Made my day that I didn't need to remove and replace! 

We ordered a thermostat from your store and repaired ourselves. Saving hundreds I'm sure. 

Found the thermostat with the connector that looked like it was slightly burnt. 

Inspect door switches and thermostat, found that one of four thermostat showed burned signs on the wires, then review continuity with multimeter and it didn’t show in a normally closed thermostat