LG LMV1762ST/01 won't heat

[BillInFlorida]

Model Number

LMV1762ST/01

Brand

LG

Age

6-10 years

I saw this same exact problem in a post here from 3 1/2 years ago for this microwave. Without opening it up, as I didn't have time, I ordered a magnetron based on that post so I could get the part delivered asap.

It didn't fix the problem. At that point, since the unit was down off the wall from under the cabinet, I got out my meter and did some checking of all the major components listed in that other post. They all checked good as far as I could tell. Then I checked the LG EAF36358314 Fuse Assembly. No continuity! Doing a search for that part, I found that I wouldn't be able to get it for several days.

Inspecting the Fuse Assembly, I discovered that it splits open, and inside it takes a standard 0.9 amp glass fuse. A quick trip to the hardware store got me a 1 amp slow blow fuse, which would have to suffice as I'm going out of town for several days and the wife needs her microwave! The hardware store fuse is slightly shorter, but the same diameter at the ends so it fit well enough in the fuse assembly.

My question is what caused the fuse to blow? Could it have been the mag tube which I replaced, or something else? The fuse assembly runs between the HV Capacitor and the HV Transformer.

 

[Wx4usa]

I believe you are correct that the old mangetron blew that fuse. Not all microwaves have one in the HV section, but LG/GE do on most models. Being physivally shorter, just make sure the wire caps are seated well on each end.

 

[BillInFlorida]

Yes, wire caps are firmly seated. My only other concern is going from a 0.9 amp (and possibly fast blow?) fuse to a 1 amp slow blow fuse, but it is working so I'm not terribly worried.

 

[Wx4usa]

I would get the factory one in there as soon as you get back home.

 

[BillInFlorida]

Thanks.

I did test the old magnetron as well and I had continuity, but as the post from 3 1/2 years ago mentioned, they can test good but open up under use.

Symptoms, by the way, when it went bad was a slightly louder humming noise for a little bit that then went away.