Depending on your technical skills , there are basically 4
components which you can check than normally cause this type of error in
PLEASE READ HERE
HOW TO DISCHARGE YOUR CAPACITOR
AND SAFETY PRECAUTIONS BEFORE DOING ANYTHING!!!
Firstly , check
to see if your microwave is fitted with a fuse. This will normally be
located inside the casing and it is not very common for a microwave to
have a fuse , so don't worry if you can't find one. If you are in doubt ,
let me know and I will look up to see if there is a fuse for you to
Open the casing of you microwave and look at the back
right of the unit for the following.
HV Diode is located near the
power supply and is identified with a symbol like in the picture below.CLICK FOR IMAGE
diode for physical damage like a crack , bulge , burst or burned smell
as they normally fail physically. To test , set a multimeter to test
resistance at 10k ohms and test. A normal diode should read 50-200 k
ohms. If not , replace the diode as it has gone. Remember that the
polarity is important , so test it both ways (or put positive to anode
Next component to check is the HV Filter Capacitor.
This component is a big circular steel tube on the board/mounted near
the HV diode.
Locate and remove any leads going to the capacitor
AFTER DISCHARGING THE CAPACITOR.
Now , set you multimeter to
resistance again to the highest available setting. Now put it onto the
terminals for a few moments (Should read infinite) and then switch the
leads around. The reading should go to almost zero and then go back to
infinite. Also test between each terminal and the casing (if not covered
in plastic) and this reading should be also be infinity. This test
might not work if your multimeter is digital and has a very high
latency. If it's a good quality multimeter , it should work fine.
inspect the capacitor for bulges , leaking , a strong burnt smell or a
crack and replace if any of the test fails. These capacitors are
designed to fail at the top of the capacitor where steel is visible , so
check here especially.
If neither the Diode or the Capacitor is
defective and there is no fuse, by process of illimination , the only
thing left is the Magnetron. Depending on how expensive your oven was it
may not be worth replacing as it's a expensive component. In your case
, it would cost about $50-$100 for the magnetron , so you might just
want to buy a new oven.
Most of these components can be found or
ordered at radio shack (diode and capacitor) or most any other
electronics supply store or www.repairclinic.com (magnetron). If not ,
contact the GE directly.
Feel free to ask if you need more info
or have any questions.