Last evening while using our seven year old microwave there was a loud
bang and everything stopped.
I determined that my circuit breaker tripped and the microwave would
Initially, I thought I detected a black powder residue near the
microwave door, but upon taking it down from the cabinet over the stove
and taking the cover off, I can't find anything that looks "fried" .
An appliance parts store nearby suggested that I have a technician (they
recommended) look at the magnetron.
Would that be the circular part about the size of a silver dollar and
3/8 " thick that is located in the base of the oven at its center?
It has two very thin wires coming out of it.
First of all it's really dangerous to cook black powder in your
microwave, save that for your flinklock! :-)
No it's that's not the magnetron. If you can't recognize a magnetron,
you should not be in there. If you put it together incorrectly you can
expose yourself to both high voltage and high power RF radiation.
However, you can "fix" it yourself. I had a magnetron burn out and I
looked into replacing it. I found three sources on line for the
particular magnetron that I required, cheapest one was $100. I bought a
new microwave for $70.
I know magnetrons are cheap to the manufacturer (like $10, perhaps
less), but I could not find a onesies-twosies distributor that was
cheap. Considering that you *will* have to have someone qualified
install it, *will* be cheaper to buy a new oven. Seven years is a good
run in this modern not-built-to-last world.
Amen to that! When my last one bit the dust I looked over what Sears had
on their floor and picked up a good sized "floor model" GE microwave for
$49.00. And, I didn't have to waste time cutting up a carton and
stuffing it in the trash.<G>
My name is Jeff Wisnia and I approved this message....
My 20 yr old Sharp MW had a loud snap,then went dead.Problem was a shorted
HV cap.I replaced it,the NV diode,and the open internal 30 A fuse,total
I got the parts at a local apppliance repair store.That was in 2000.
The MW still works today,gets used daily.
Since you can't identify electrical components,I suggest you take it to a
local apppliance repair store and let them repair it.
If you are not electrically inclined, do this. . . . .
Open up the case. Where the cord enters the cabinet, look for a
fuse. It will look like the old glass tube automotive fuses. If
it has blown, replace it with the same model # from an appliance /
If it runs again, great!!!! If not, junk it.
Keep the whole world singing . . . .
DanG (remove the sevens)
We had a big Sharp Carousel that went dead suddenly after only 34 years. I
never throw anything out so we put it on the shelf and bought a new one.
But mention of the fuse now made me curious, so I took it into the shop,
pulled the fuse, and it was blown. Now my problem is identifying the
current rating of the fuse. I can't read it all because one end is
I see "250 VOLT" on one end and "BUSS ABC" on the other end followed by a
"/" and I think a 5. The body is ceramic. The Sharp model number is R-9330
and it uses 1.3 kw.
Would anyone know what the current rating should be and what code if any
they might be using ? If I can find the right fuse and it works, we know
someone who could use it.
Most older microwaves have used a 120 volt 15 amp fuse or an 250 volt
15 amp fuse. Newer higher power microwaves have switched to a 250 volt
20 amp fuse.
If the end of the fuse is burnt a bit, the fuse holder may be not
holding the fuse tight enough and the end of the fuses get
burnt/scratched a little.
Fuse holder may need to be changed as well.
Appliance Repair Aid
My Sharp R-9310 blew it's internal 30 A fuse because the HV capacitor
It only cost $26 USD for a new cap from the local appliance repair store.
Considering that any 120VAC branch circuit in your house willnot have any
greater than a 20 amp breaker,a 30 A fuse seems reasonable.
Look at the back plate and see what the ampere rating is stated. 1.3
kW divided by 120V is about 11 amps, so if this is the main fuse in
the 120 V circuit it should be something less than 11 amps. If the
fuse is for a higher voltage circuit it might be 5 amps or lower. The
250 V rating isn't really an indication of the voltage of the
circuit. I would just buy a 5, 7, and 10A fuse and try each starting
at the low end and use which ever one didn't burn out. Of course,
something made it blow so you may have something else wrong. 34 years
is really old, I would junk it. buy a new little one for $50.
I expect it has a rotating plate. That part may be the motor for it. You
probably blew an interal fuse as well. I doubt that it would be worth
repairing. Only one I would even consider repairing would be a combination
convection and microwave.
Forget it. Anything you do is likely to cost way more than a new
microwave. If you really want to poke around, look at everything
until you find something with a hole in it or a big black burn. But
if you get it fixed it is still an old appliance and something else in
it is likely to go.
If you do go ahead and tinker with this thing, keep in mind that a simple
misalignment during re-assembly can render RF leakage and possibly injure
future users. This is one repair that is best left to certified
technicians or factory rebuilders. Microwave radiation is not something
to be played with!
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