Microwave is working but stopped heating and smelled like rubber, Is this typically the Magnetron? Is there a strong possibility of something else you may suggest? I am handy and can take the unit out of the wall to do repairs, however for this repair would you recommend a tech or a relatively simple repair? I know that is a hard question not knowing me, but I will try anything once unless I need a specialty person.
Thanks for any help you can give me.
Answer Hello Todd. You most likely have a "high voltage" side malfunction. Transformer, diode, magnetron, Capacitor. You will need to be extremely careful if you decide to test the components with a multi meter, Very high residual voltage is present, so make sure you remove power to the microwave and short across the terminals on the capacitor. The magnetron should have a reading of less than 1 ohm resistance across the two terminals, and an "open" circuit between each terminal and chassis ground. The diode/rectifier should have a resistance reading in one direction only, no resistance, or resistance in both directions indicate a faulty diode. The primary winding on the trans former should read approximately 450 Ohms resistance, the secondary winding should read 80 ohms resistance, and the filament transformer should read 100 ohms resistance. If all the readings are proper and in range, replace the magnetron.
The magnetron on the microwave has been replaced a few years ago. At the time, the microwave was not heating properly. The problem I'm having now is that when the microwave is in use, it sometimes makes a loud, low, rumbling sound. I'm not sure where it is originating but it is a concern. Any thoughts on what might be causing this?
With the noise being a rumbling noise then the possibility of what it could be is the turntable motor or the transformer. The transformer normally would make a buzzing type noise rather than a rumble but could be either of these 2 items. You will want to try to pinpoint where the noise is coming from and one thing that you could do is to disconnect the wire from the turntable and see if the unit is still making noise. This would narrow the issue down.
What could be the problem? On this unit the mircowave section is not heating. First, I replaced the L & R side door switch assy. It worked, then the next day it did't work. Next, I replaced the cap.& diode it worked, then the next day it did't work. Please help. I am thinking magnetron, what do you think?
Answer Hello Alf,
You could test the transformer and the magnetron to see if they are bad. Using multi-meter measure the tranformer with the leads disconnected Primary, secondary and Filament to ground. You should read less than 1 ohm on the primary and secondary. Filament to ground should be 0 ohms. Measure resistance of primary and filament should be infinite. Check the magnetron touch the leads to f and fa terminals should be approximately 0 ohms and measure from filament to chassis and should be 0 ohms. Anything other than these readings means the part is bad. If the parts check ok then you would want to replace the control board. You can test this with a multi-meter TJMA-DMT3. Here is a link on how to use a multi-meter. http://forum.appliancepartspros.com/oven-repair-including-ranges-cooktops/4810-how-check-continuity-ohmmeter.html