How to Troubleshoot & Replace Samsung AP4044834 / 3405-001034 Microwave Door Switch

Changed out sensors in door. Did not realize there were more than one. Changed one that fixed problem with door and then had to get another one so oven would work right. Next time I will do a little more research. Changing sensors was real easy and only takes about 15 mins to do. I received parts in just two days, great service!!!!! Thank you. 

It took me about an hour total just from taking it apart trying to move the sensors around for the door putting it back together and then ordering the parts. It was fairly simple. 

Internet search pointed the problem (most likely) to the thermostats and door switches. I used a multimeter to check the continuity of the parts and found problems w/ the thermostat. I did not need the switches but I misdiagnosed door switch. You need to test continuity w/ the yellow switch pressed in; this is the same as the door being closed. I tested it w/ door open which will show that the circuit is "broken" and not continuous, a rookie mistake. I replaced the thermostat and everything works fine. The actual installation is a no-brainer but it's the research / troubleshooting that the most difficult part. So do your research so you don't end up ordering unnecessary parts. 

One of the door latches (there are 3) stopped working. I loosened the control panel (3 screws) to access the switches. I unplugged the slide on connectors and used a vom meter to check them when the door was opened and shut. I replaced the bad switch. Saved a $180 repair Bill for a $20 part. Used u-tube for how-to-do it video. 

Replaced micro switches in door 

I checked online and found out that it should be the door switches. Chatted online with Heidi(?) in AppliancePartsPros.com. Very helpful. Confirmed that it should be a switch, and suggested I change out all 3 of them. She gave the exact switch part numbers to use. I looked at a YouTube video and realized I could not do the repair myself as I have a neck issue. My 22 year old son was able to fix it rather easily under my supervision, in less than an hour. The only thing we had to figure out was that to access the clips to remove the switches, he had to first remove the long plastic frame which held them behind the latch sockets. Tips: (1) Two of the switch part numbers are the same although all three look the same. Make sure you note down which two are the same in the microwave as you remove them! (2) Take a picture of the connectors for each switch before you disconnect, so you know which connector to use for the two connections. 

Replace the door switch. 

Tested door interlock switches. Found one switch bad. Ordered the door interlock switch bracket assembly (which, by the way, included all 3 new switches. Installed assembly in 15 minutes. Works perfectly now. 

Test Associated toggle and replace. 

Replace the upper and lower door switches