What do we know about Microwave Repair?

All I know is that my microwave should not sound like this...

GE Profile Model JEBC200W wall mounted, built in Microwave/Convection Oven

Odd background.  My house was built in 1973 as a summer home.  The first guy kept the place 8 years and then sold it to another who used it as a summer home (private residence, no renting out.)  In 1994 the kitchen was remodeled.  It was at this time that the house got a full suite of GE high end appliances.  Induction cooktop, wall mounted electric oven/convection oven at the bottom and this separate microwave/convection oven at the top.  About 2 years after the kitchen remodel she  passed away and the story is that he never cooked again but rather was a constant regular at a lot of local restaurants.  

So, though this microwave oven is 26 years old, it does not have 26 years worth of wear on it.  We bought the house 9 years ago and we are the first people in the 47 year history of the house to live in the house year round.  I mention this because we have but more wear on this unit in the past 9 years than were put on it in the preceding 17 years. 

Do you think it can be saved?  I have little hope of parts availability for a 27 yr old unit.  

Kitchen remodel will have to wait for a planned big remodel of the bathrooms/bedrooms.   

Tonight, during a 4 minute cook of corn, I returned to the kitchen to hear this noise.  The microwave did not start that 4 minute cycle with the noise.  The noise arrived somewhere mid cycle.  

FWIW, a few years ago, the handle on our then-21-year-old GE microwave snapped. I found the part number for the replacement, but it was NLA.

Then we saw that modern microwaves offered way more interior space despite fitting into the same size hole. Then we realized that everything was getting a bit threadbare--not bad or broken, but just cracks here and there.

So, soon after, all new appliances. 

What I know about microwave repair is keep the cord before you smash it up and replace it.

This $2,333 unit seems to be GE's spiritual successor to our unit.  Ouch, steep.  

Also finding this unit, $600 where "wall mount" just seems to be a countertop unit with a dedicated trim for closing off the old hole in the wall.

On GE's website I found this diagram of my unit but no parts listed.  

Not to get too technical on you, but it sounds like a whirring fan thingie is hitting something it's not supposed to.

Our GE Profile microwave lasted about 10 years.  I bought a similar model from Costco.  Never really considered fixing it, which is curious, because I've spent a lot of time fixing dishwashers and washing machines.  Something about microwaves makes them seem bad candidates for DIY repair. 

Maybe call a local appliance guy and see if he services old GE microwaves?  My experiences with our local guys have been favorable.

1988RedT2 said:

Not to get too technical on you, but it sounds like a whirring fan thingie is hitting something it's not supposed to.

Agreed.  And there appear to be 2 fans in that unit.  One for cooling the magnetron one for convection.  

In the video are you using the convection function or no?  Im guessing no, indicating that is likely the #6 fan in that diagram causing the problem.

Normally I'd be hesitant to take that apart and look inside, but given the replacement cost you are looking at, I would dive right in.

Microwaves scare a lot of people.  They aren't really dangerous as long as you NEVER EVER power up the magnetron with it removed from the cavity/door open/etc.  

Check on repairclinic.com for parts they list a bunch of parts but many are "special order".  I've found that just means an extra few days for delivery.  It looks like they list two different fans.

Pull it apart and see what is touching what it shouldn't be.  I just did a magnatron on a 6 year old LG. It took me about 15 minutes.

David S. Wallens said:

FWIW, a few years ago, the handle on our then-21-year-old GE microwave snapped. I found the part number for the replacement, but it was NLA.

Then we saw that modern microwaves offered way more interior space despite fitting into the same size hole. Then we realized that everything was getting a bit threadbare--not bad or broken, but just cracks here and there.

So, soon after, all new appliances. 

Granted ours is much newer, but I took the GRM approach when the bottom mount for the handle broke (screwed through the door into the handle). I could have taken the inside off, replaced the handle and screw, blah blah.

I just packed it full of epoxy held it firmly against the door for a few minutes. Voila!

I recently had to replace a door switch on our microwave because - for whoever's genius idea this was - the failure mode of the door switch is to momentarily ground the power therefore tripping the breaker. 

Not sure why creating an intentional short is a good idea, but it is apparently common to many microwaves after searching the internet...

But other than that I don't know much. Keep searching google, chances are you're not the first to have this issue and write about it. 

Robbie (Forum Supporter) said:

I recently had to replace a door switch on our microwave because - for whoever's genius idea this was - the failure mode of the door switch is to momentarily ground the power therefore tripping the breaker. 

Not sure why creating an intentional short is a good idea, but it is apparently common to many microwaves after searching the internet...

But other than that I don't know much. Keep searching google, chances are you're not the first to have this issue and write about it. 

Maybe the thinking is that if the door swtich has failed you might be able to inadvertantly operate the thing with the door open which is probably really bad, so if the switch goes out the fail-safe position is to make the thing totally inoperable?

Just guessing.

I've had good luck searching https://fixitnow.com/samurai-appliance-repair-forums/ in the past.  Never had to post anything because I think all the problems in the world have already been posted, fixed, and explained in detail.

Parts are expensive.

We bought a new microwave for aesthetics reasons. Nine months later the power supply and magnetron failed. Sears doesn't warranty like "here's a new microwave" warranty. They warranty like "We will send a tech to your house twice and buy way more than microwaves' worth of parts" which they did. Tunawife needs a microwave daily to sanitize her medical stuff, so we bought a new one in the meantime, and I now have a brand new microwave that I don't want.

I guess I'm saying: Want to buy a microwave?

Two weeks ago (same video as above)...

30 minutes ago...

Back to running quiet!  (But, rewatching the video makes me realize I should lube the door spring)

The culprit was the #6 fan assembly in the diagram in the post above.  The part, labeled Samsung in this 1994 microwave, seems to not be available anywhere.  My intention was going to be to try and tear it all down and see if I could retro fit in a desktop computer style fan in the same place.  Or, source some sort of fan that would work in its place.  

Once torn down, I came across a stray part on the machine floor.  It was a sort of round spring clip.  It had some green goo on the clip.  The green goo matched the same as the goo on the end of the fan shaft.  It seems the intention of the spring was to keep tension on the plastic fan blade and keep it adhered to the fan shaft.  I was not sure if the green was intended to be an adhesive and wasn't sure what would be a good replacement...my answer was plan white house caulk.   I think the fan blades had been hitting the metal fan frame and that is the resulting metallic sound.

More photos... 

My ten year old no name microwave's button panel slowly worked less and less until the thing was borderline unusable. So, my parents, having just moved, gave us a really nice higher end (and massive) LG that was barely 5 years old. That lasted 2 months. I received a brand new Samsung for my birthday a month after that. It lasted 3. Tried to deal with the warranty but it was a lot of back and forth and I just said screw it. 

Been about a year without a microwave—honestly don't miss it.

I had the heat gun out because one sheet metal screw wanted to fight and was beginning to strip.  I hit that screw with a lot of heat and it turned easily.