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

I used a voltmeter to test continuity on parts. I found 2 thermostats burnt out. I replaced all of the thermostats and also changed a capacitor. It now works well! 

You tube video showed how to jumper thermostat to test. Replace thermostat. 

After getting help from your service tech the problem was narrowed down to thermostat; 101na,250/, which is located on the magnatron. The part came in 2 days and took 5 min. to replace. The micorwave now works like new. Thank you. 

Troubleshooting procedures identtified two oven thermostats (located behind the panel board) were defective. After removing the panel board, the oven thermostats were easily accessible. Replaced both oven thermostats, turned on microwave, only to discover the exhaust fan ran continuously until I unplugged the microwave. Forntunately, I came across an on-line appliance repair forum, where a person had the same problem with the continuous running exhaust fan. This person stated he was able to solve the problem by connecting only one line to the oven thermostat (which connected to the exhaust fan) and left the other line unconnected but wrapped with electrical tape. Plugged the microwave in and has been running normal ever since.