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

Replaced upper microwave door switch. Pretty easy to do, make sure you disconnect motherboard before removing switch panel. 

After searching the Internet this particular problem, found out it was a micro switch. located the part appliance parts pros. ordered the part. Installed the part as per YouTube instructions. A $5 part cost $10 to ship but better than $200 for a new microwave! 

Unplugged the microwave, then unscrewed the control panel. Then 2 screws to take the front plate off. 2 screws to undo the switch plate. Carefully pulled out the switch plate. Removed the bottom switch and took a picture of where the 2 wires where hooked on the switch. Took off the 2 wires and removed bad switch. Then replaced it with the new switch and reinstalled the 2 wires. Carefully put switch plate back on and rescrewed. Then put control panel back on and face plate. Plugged microwave back in, and done. 

I replaced all three of the safety switches, and now my microwave is working again. 

I ordered replacement parts and installed them. 

Removed and replaced the door micro switch. 

Replace the switch 

Replaced the door latch switch behind the control panel. 

Replace the micro-switch. 

With help from the internet and the Appliance Parts Pros the hardest part of the repair was removing 3 torx fasteners used on the cover. I ordered both the safety switch and door opener switch, however only the door switch was defective. The switch had overheated and welded the quick connect to the spade connector on the switch itself. After cutting the connector wire and crimping on a new quick connect and installing the cover the microwave is back in service. Shipping charges are a bit high for the two parts; overall still a bargain over purchasing a new oven. Taking it for repair would be just as expensive as buying new. You do not need to be a repairman to tackle this job, if you can read and follow directions, be cautious of the safety involved while working with electricity, and have a few simple tools anyone should be able to successfully complete this repair. The internet is awash with many useful videos that a novice can learn from and build confidence not only for this but other repair tasks as well.