Microwave turns on when door opens

Microwave Repair
1

Brand: SAMSUNG MICROWAVE
Model Number: SMH1713S
Main Symptom: Microwave turns on when door opens
What happens & when:

I had 3 switches replaced in the past when door would not close properly. Only one switch was bad. The Microwave actually turns on when I open the door. Very frightening. Almost got caught a couple of times. I hope it is just a fan starting up at first. I expect to change three switches again. Last time they were two (2) 3405-001034 and one DE34-20019A. Now the former is the same but the latter is replaced with 3405-001033. The description of the function of these swtiches (from a diff. website) states they all do the same thing, safety shutting off of the microwave when the door is open. Are these the correct quantity and part numbers I need? I am looking for your video on how to install the switches because I have to do it myself and no experience here.

Please advise about the parts; are they correct and do they have the exact same function? Please show me where to find your installation video for this issue. Lastly, when the microwave starts up, is that a fan running or the actual micro waves flying around? Thank you for your prompt response. Very truly yours, Denise Grempel Corona, CA 732-735-1832 12/31/2025 3:15 PST
2

Hey Denise, there are 3 safety switches, 2 are alike, the third one is different, as you have noted by the part number. Typically, the 2 that are alike are the ones you will need to replace. If there is a tech sheet on the MW, it will show you the location of the switches and how to test them with a multimeter. We don’t have a step-by-step video on your specific model, but you can find videos on YouTube on how to swap them out.