How to Troubleshoot & Replace Lg AP4437957 / 3B73362F Microwave Door Switch

Replaced the door switch. 

Checked oven door micoswitches and found one that was broken. ordered replacement. Installed in 10 minutes. microwave oven works like new.. 

Replaced micro switch 5 minute fix. 

I used a simple volt meter to check continuity on the thermostat and switches. I found a switch that was not working on the microwave and a thermostat that was not working on the oven. Simple fixes that cost 30 bucks if you are willing to open it up and look. The oven was a little more difficult, but only because I had to pull it out of the wall. 

Simple conductivity test on the door switchs. Replaced bottom one. However they don't come out with out breaking the holddown tabs, too brittle. So I used a self tapping screw to hold in place. Plugged it in and made some popcorn, works great again. 

Replaced primary micro switch and connectors, ok now 

Searched the web for troubleshooting tips and couldn't believe how easy it was to isolate the problem, which was a failed door interlock (a small switch). I ordered the part from ApplianceParstPros.com for under $4 (plush shipping), and it showed up in less than two days! We were already under a great deal of stress in the face of my pending transition from the military and selling our home. AppliancePartsPros.com (and some repair tips from others on the Internet) made this repair simple, and it was much more affordable than spending $300 for a new microwave. My tip to you? Never be afraid to try and do it yourself. Look it up online! If it looks like something you can handle, why not save your money. I did! 

We replaced the primary switch, it had went bad, everything else worked but did not hear the food! 

Chatted with appliance pros and they determined it was one of the door switches. I ordered both and when they arrived I watched a youtube video on similar problems. So I took control panel off and found switches and replaced top one first. Took 5 minutes. Low and behold my microwave turned and and was working. Thank you appliancerepairpros.com!! You saved me $145 on a technician! ! 

Replaced two micro switches.