• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

    Jake
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Frigidaire Microwave FGMV176NTF blows breaker

Cmerrill

Premium Member
Joined
Nov 12, 2020
Messages
8
Location
Mississippi
Model Number
FGMV176NTF
Brand
Frigidaire
Age
1-5 years
So it happened twice the past week if I opened the door with the microwave running it blew a breaker. Now it will blow anytime you hit start and try to use it.
 

rickgburton

Appliance Tech - Moderator
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Messages
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Sounds like a bad interlock switch. Check it for continuity by opening and closing the door.
 

rickgburton

Appliance Tech - Moderator
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Probably. It's a normally closed switch but you should check all of them. Remember to remove at least one wire when checking continuity
Microswitches.jpg
 

Cmerrill

Premium Member
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Messages
8
Location
Mississippi
Ok so after purchasing the above part there is an improvement. The microwave will now operate instead of blowing a breaker when you hit start. However, it still blows a breaker when opening the door while operating. You have to wait until it’s done to open the door.
odd because I tested continuity of all the switches and replaced the one that had no change operating the switch. It was the middle one.
 

rickgburton

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It was the middle one.
That's called the monitor switch, sometimes called the "dead man" switch. It's purpose is to keep the microwave from running with the door open by shorting L1 and Neutral together. When you open the door L1 to the monitor switch is interrupted by the primary switch. The primary switch needs to open just ahead of the monitor switch. That's the reason you need to test the switches by opening and closing the door. The bracket that holds the switches could be worn out or out of adjustment. There's very little adjustment but you can loosen the screws and push the bracket in place the tighten the screws.
 

Cmerrill

Premium Member
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Messages
8
Location
Mississippi
Yeah now the monitor switch ( the one I replaced and the one you have constant access to) is constantly depressed. I can try pushing it with a screw driver and it’s in the constant down position.
The last one did this. Even with the microwave unplugged. Which is why I replaced it. It would not reset.
 

rickgburton

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OK, if the microswitch button is pushed in and stuck in that position, the switch is bad.
 

Cmerrill

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Nov 12, 2020
Messages
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Location
Mississippi
Well there has to be something else going on too right? When I initially replaced it the microwave would work but blow a fuse upon opening the door. I’m wondering if I should replace all the switches. Also thinking this would should be replaced no charge since it was just purchased. What’s your thoughts?
 

rickgburton

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Did you get it from Appliance Parts Pro? Ask them. I'm sure they will replace it for you.
 

Cmerrill

Premium Member
Joined
Nov 12, 2020
Messages
8
Location
Mississippi
Did you get it from Appliance Parts Pro? Ask them. I'm sure they will replace it for you.
Did you get it from Appliance Parts Pro? Ask them. I'm sure they will replace it for you.
I did. Do you know what the other two switches are? This one is the one in the middle. The one you can activate without taking the microwave apart. I’m assuming the two are different part numbers? Is that right?
 
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