I have one of those SpaceSaver GE microwaves that goes over the range. It
doesn't heat. The lights come on, and it whizzes and whirs, and the
turntable moves, but no heat.
Are these worth getting fixed? Are there user serviceable fuses? Would I
be tossing good money after bad to have it fixed, or should I just replace
Probably the transformer. I had an Maytag lunch 10 months after install. I
saw the list price for the transformer that the guy installed under
Best check the price of a transformer and then see what the after holiday
Fuses in a microwave, you must be kidding.
He's not kidding. There may very well be a fuse in there. It is generally a
Beside the transformer, the magnetron might be bad. How old is the unit.
Sometimes the magnetron is warranted for five years.
If it is not in warrantee, and more than a fuse, it is replacement time.
I've fixed microwaves several times simply by replacing the fuse. They
have been standard fuses. The symptom has always been "nothing works".
If things light, turn etc. the fuse is probably not the problem.
Before you do anything, unplug the power, wait a few minutes and plug it in
again. Then test. I had one go out and bought a replacement. When
removing the old one, plugging it in again resulted in normal operation. I
subsequently read, somewhere, that this is a recommended procedure -- too
late. Don't remember the explanation -- internal circuit breaker perhaps.
Even at small odds of success in your case, this is too easy a test to pass
And to answer, in advance, the obvious question --
The plug on this over-the-range unit was not accessible until it was pulled
from the wall mounted cabinet to start its removal and replacement. Turning
off the branch at the circuit breaker probably would have saved me several
Worth fixing yourself, almost definitely, provided you know how. Worth
having fixed? I don' t know.
I don't know the specifics of that model, but in general the
transformer tends to be one of the most reliable components, and it's
more likely that the failure lies elsewhere, such as in the magnatron
tube, high voltage capacitor, high voltage diode, or controller that
activates those devices through the transformer. www.repairfaq.org has
a great deal of information about repair of microwave ovens, and heed
its precautions about high voltage and microwave leakage. Don't work
on the oven unless you understand electricity and all the safety rules
for working with it. The high voltage (2,000V) cannot safely be
measured directly, but you can use a neon bulb glued to the end of a
long insulating stick (wood or plastic) and run it along the
transformer wires leading to the magnetron to see if they glow. The
glow will be dim, and you probably won't see it except in a semi-dark
room, but any glow indicates a good transformer. The high voltage
capacitor can be checked with an ohmmeter, but first you must unplug
the AC power and discharge the capacitor with a 10,000 ohm, 10 watt
resistor. One wire lead of the resistor must first be connected
securely to bare metal of the oven chassis, the other lead wrapped
around the shaft of a screwdriver having a plastic insulated handle.
Touch each lead of the capacitor with the screwdriver tip for at least
30 seconds. Finish discharging the capacitor by removing the
screwdriver from it and connecting it directly to the oven chassis with
a wire wrapped around the shaft, and touch the capacitor leads again.
These high voltage capacitors contain a bleeder resistor to discharge
themselves when the AC is turned off, but you should never rely on it
since many fail in use. The high voltage diode will almost always test
bad with a digital meter because it consists of several diodes in
series, and you may have to use an analog meter set to an ohms scale
that applies 9V to it. On the magnetron tube should be a bimetal
thermostat wired in series with the 120VAC circuit, and it may have
gone bad from years of heat. When I replace a magnetron I replace
this, the diode, and the capacitor since they cost just slightly extra,
but parts prices can vary greatly, with appliance parts sources tending
to be the most expensive, mail order electronics supplies, such as MCM,
Parts Express, Premium Parts, Electroniic Parts Supply, tending to be
the cheapest (can be as little as $50-75 for everything). Another
thing to check is the magnetron cooling fan (120VAC) and any of its
ductwork. When replacing the magnetron, be sure to clean off the
sealing surfaces first, and torque down all the nuts or bolts correctly
because a bad seal can allow strong microwave leakage. Test the oven
only after reinstalling the metal cover, not only to reduce such
leakage but also to guard against high voltage or an exploding
I don't work on carburetors, fuel injection systems, automatic
transmissions, or electrical items.
I have found out that it is better if I just take it and pick it up. I can
and have changed engines in a car by myself, and that was back when cars
In June, 2002, I had a five way bypass and an aortic valve replaced. Now
the highest voltage I mess with is 1.5v AA nimh batteries. I ain't messing
up my rebuild job with a cheap microwave oven, thank you very much.
That's interesting. What's the purpose of using a resistor to
discharge the capacitor? Does it protect the capacitor?
I have a GE two years old. The magnetron won't run in the
functions that require the humidity sensor. After a couple of
minutes, the display says F4.
Inside the metal box is a schematic in an envelope.
I haven't been able to find out about humidity sensors. This one
has two elements. Each reads about 3.5 K ohms. It doesn't change
much if I lay the sensor and plate on a cup of water.
Well, I just got home from R. C. Willey. Bought a new one with a dent in
the side for $167. The dent will be covered up by the cabinet. Will advise
when I take this other one to the shop what the repair costs are. If it is
fixable, I will just take it to the cabin, as the one up there is ancient
with the twist dial timer. Probably a pretty good unit, though, as most of
those last about twenty years. If it's toast, then I got a good deal.
I didn't get it wet. I suppose the problem is on the board or in
the sensor. The sensor is in a perforated can. I don't know how
to test it. If it proves to be faulty, maybe mildew grew in it
during the summer. Washing can help some electronic stuff if you
let it dry. I don't know if a humidity sensor is an exception.
I bought a small GE microwave at a garage sale for 2 bucks. It did the
same thing as you described. I got a used transformer for 5 bucks at
the local appliance store, for some reason they had taken it out of
another microwave and it was setting on a shelf. Seemed to me like it
was worth a try. Put the used transformer in and that fixed it. It's
been working since, 5 or 6 years since the repair and I use that
microwave a lot, a whole lot. I remember the guy said the transformer
was from a different brand but it was obviously the same transformer.
needs a magnetron tube,usually they have 5 or10 year warranty on the
part only you pay the labor charges I retired from g.e. 4 years ago 2
men job around 150.00 to 175.00 to replace it I live in Long Beach CA
I had a Jenn-Aire** with a fuse, but it didn't do anything when the
fuse was bad. After I replaced it, it was fine. Although I gave it
to Goodwill so I don't know how long it worked. ( I figure forever,
but I don't actually know.) Ceramic fuses, 5A, four for 2 dollars at
Wouldn't hurt to look inside. They might have the fuse in another
poart of the circuit.
I also had an Amana Radarrage Model 2. Seriously, the original
microwave oven. I got it in 1980 and it was probably 10 or 15 years
old then. It broke once, made humming and zapping noises, and the
woman at the parts deperatment told me it was probably the microwave
tube. A lot of money. For some reason I had to call back and then
she said it was probably the diodes. Only 50 dollars (when new ones
cost a good deal more than that>). I think on a different call, I
tried to buy the schematic but she wouldn't sell it me because she
thought I would boil myself. I tod her I had been doing repairs for
30 years and I begged, and she sent me one maybe for free.) It was
simple and I shouldn't even have needed it.
Anyhow, I finally ended up just applying some GE silicone cement to
the wires that went from the flat selenium? diodes, so that sparks
would stop. That fixed it. I put it on twice as thick as the
insulation had been. Worked for years.
Then I think it broke a second time and the third time it broke, it
was the transformer. $300 dollars. I pointed out that one coudl buy
a new one for 75, and he told me to write to Amana, Iowa. I wrote the
them and they told me to call York Pa. I called York Pa. and they
wanted 300 dollars. They agreed to sell it to me at the repairman's
price of 170 iirc. I liked having Model #2 but it was still too much
money to pay for a 25 year old item. (it had two mechanical timers.
One for a minute and part of it and one for 30 minutes or a part of
it. But no other features. It was big too. Big enough for anything.
**(blew the fuse when my brother put something metal in that shoudln't
have been there. He put in the wrong metal rack, not the one made for
the inside of a mcirowave.)
Remove NOPSAM to email me. Please let
me know if you have posted also.
I have seen 2 microwave ovesn that failed to heat due to a burned PWB
trace leading to the relay that controls the primary power to the
transformer. If the fuse is good but the xformer is not getting
primary power and the relay is clicking in, check the PWB for burned
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