Microwave help-Frigidaire model FFMV164LSA

[AWSHandy]

Hello,  having trouble with a microwave.  Every 3-6 months the microwave goes dark.  Line fuse blows.  I can replace the line fuse, then it happens again awhile later.  I have done some reading into what causes the fuse to blow...incoming power/surge, door switches, magnetron...what else.  What is most likely.  I have tested the door switches...all good.  What is the most likely culprit.  I am thinking of changing out magnetron and HV diode.  I have done this before, I know how to unload capacitor.  Thanks for any help

[Vance R]

Odds on bet would be door switches or door switch timing.

[AWSHandy]

Vance, I tested all doors they all tested ok.  ????

[AWSHandy]

door switches

[Vance R]

So next would be timing of the door switches, the primary and secondary switches have to open before the monitor switch places a direct connection between line and neutral.

[vee8power]

On 10/28/2021 at 10:19 AM, AWSHandy said:

Every 3-6 months the microwave goes dark.  Line fuse blows. 

Does this happen when you open the door?

[AWSHandy]

No, plus the door switches have been tested. They are all operational.

[nolazach]

Had same issue.  There is a service bulletin on this model to where you have to replace the switches and their support.  Apparently the problem is caused by a partially open monitor switch. 

[FIXIN1]

I've run into a few of these lately and i found this part # 5304509457 has the support and latch hook and spring. not sure if the door switches come with the support, I will update soon