You are absolutely correct. I do not understand this silly test that you-tubers post on youtube not understanding that other stuff can be wrong with a magnetron. I just replaced my bad magnetron that had passed every test with a new one and now my microwave works fine!
Thank you for your video. It was extremely helpful as well as the commentary below. Our problem started with a bad Capacitor, which I replaced. It heated twice and stopped working. Using the same methods of testing the Magnetron as you dispalyed in your video. The Magnetron test as though there is nothing wrong with it. However, I found severe heat discoloration on the housing as well as minor melting of the cooling fan schroud. I ordered a new one from Amazon based on your video, commentary and heat damage. I'm sure it will work now.
Thanks for the video! I have a GE Advantium 240 microwave that stopped heating ($2500 to replace). Tested everything: door switches, capacitor, capacitor diode, as well as the magnetron (an LG 2M246) using a multimeter, precisely the way you described. The magnetron tested perfectly with no obvious defects. I was about to give up until I saw your video. First, I put the microwave back together for a new baseline, just to make sure I hadn't "wiggled" something back into working condition. Still no heating. Second, I ordered a new magnetron for $35 from Amazon and presto; microwave heats just fine. So to your point, a positive test of a magnetron using a multimeter does not necessarily determine whether it is still good. Bottom line, if you already have the thing out for testing, just replace it; its worth a try for $35.
For the magnetron as a vacuum tube, those tests would only point to filament filtering caps problem. Many magnetrons are simply get old due to reduced emission from the cathode.
I believe the problem with that bad magnetron is the waveguide. That's the nipple-looking part surrounded by the gold-colored pot scrubber-looking metal. That waveguide looks rusted. The corrosion is likely inside the waveguide too. That will cause the waveguide to not work right, or at all. The microwave energy will get sort-of stuck in there. Waveguides must be clean and smooth inside to work. However, there is no way to fix such a magnetron. That one is scrap metal now. But save the 2 magnets, those can be useful for other projects. ;-)
A person should be very cautious while disassembling a magnetron. The pink ceramic insulator ring contains beryllium oxide which is highly toxic if crushed and inhaled.
I’m waiting for the Magnetron part to arrive, but I was looking how to test it to make sure. When the higher hum started it tripped the breaker, reset and tried again, blew the power fuse. Replaced the power fuse and powered it back on and did a 30sec heat test, I heard the higher hum again and then stopped heating. It blew the heating fuse. I tested the magnetron and I can’t find anything wrong with it digitally. So even if it tests good, it still might be bad. The diode tests good, switches are good. So I hope it’s just the magnetron.
This is exactly my problem. So, I will order a new one and see what happens. If it keeps bothering me I have a nice 20 pounds hammer that will certainly help me... Thank you
That's a very good video, and extremely helpful. You know, I have a Sanyo 2M140 magnetron that didn't heat the food sometimes, but yet checked good with both of my digital voltmeters. However, with my Conar Model 211 analog tube type voltmeter, I could detect some capacitance between the casing and the magnetron heater whenever I switched the voltmeter leads. I mean, the pointer would jump up a bit before coming back to rest, and this would occur whenever I switched the Conar voltmeter leads. In fact, I checked that capacitance with my LCR meter, and it measured approximately 0.001 uF capacitance. Would that mean anything? Oh yes, there was definitely 4,000 VDC between the magnetron heater and ground as I measured that with my high voltage meter. In addition, the magnetron overload protection checked fine.
There are capacitors within the socket from each filament lead to casing. When those caps breakdown and leak, that’s the resistance you see when doing the ohm test. New socket from Amazon corrects that problem.
That's exactly what I discovered today,it passes all the continuity testings, but still not heating up.Thanks for sharing your experience.
You are absolutely correct. I do not understand this silly test that you-tubers post on youtube not understanding that other stuff can be wrong with a magnetron. I just replaced my bad magnetron that had passed every test with a new one and now my microwave works fine!
Thank you for your video. It was extremely helpful as well as the commentary below. Our problem started with a bad Capacitor, which I replaced. It heated twice and stopped working. Using the same methods of testing the Magnetron as you dispalyed in your video. The Magnetron test as though there is nothing wrong with it. However, I found severe heat discoloration on the housing as well as minor melting of the cooling fan schroud. I ordered a new one from Amazon based on your video, commentary and heat damage. I'm sure it will work now.
Thanks for the video! I have a GE Advantium 240 microwave that stopped heating ($2500 to replace). Tested everything: door switches, capacitor, capacitor diode, as well as the magnetron (an LG 2M246) using a multimeter, precisely the way you described. The magnetron tested perfectly with no obvious defects. I was about to give up until I saw your video. First, I put the microwave back together for a new baseline, just to make sure I hadn't "wiggled" something back into working condition. Still no heating. Second, I ordered a new magnetron for $35 from Amazon and presto; microwave heats just fine. So to your point, a positive test of a magnetron using a multimeter does not necessarily determine whether it is still good. Bottom line, if you already have the thing out for testing, just replace it; its worth a try for $35.
For the magnetron as a vacuum tube, those tests would only point to filament filtering caps problem. Many magnetrons are simply get old due to reduced emission from the cathode.
I believe the problem with that bad magnetron is the waveguide. That's the nipple-looking part surrounded by the gold-colored pot scrubber-looking metal. That waveguide looks rusted. The corrosion is likely inside the waveguide too. That will cause the waveguide to not work right, or at all. The microwave energy will get sort-of stuck in there. Waveguides must be clean and smooth inside to work. However, there is no way to fix such a magnetron. That one is scrap metal now. But save the 2 magnets, those can be useful for other projects. ;-)
A person should be very cautious while disassembling a magnetron. The pink ceramic insulator ring contains beryllium oxide which is highly toxic if crushed and inhaled.
I’m waiting for the Magnetron part to arrive, but I was looking how to test it to make sure. When the higher hum started it tripped the breaker, reset and tried again, blew the power fuse. Replaced the power fuse and powered it back on and did a 30sec heat test, I heard the higher hum again and then stopped heating. It blew the heating fuse. I tested the magnetron and I can’t find anything wrong with it digitally. So even if it tests good, it still might be bad. The diode tests good, switches are good. So I hope it’s just the magnetron.
This is exactly my problem. So, I will order a new one and see what happens. If it keeps bothering me I have a nice 20 pounds hammer that will certainly help me... Thank you
That's a very good video, and extremely helpful. You know, I have a Sanyo 2M140 magnetron that didn't heat the food sometimes, but yet checked good with both of my digital voltmeters. However, with my Conar Model 211 analog tube type voltmeter, I could detect some capacitance between the casing and the magnetron heater whenever I switched the voltmeter leads. I mean, the pointer would jump up a bit before coming back to rest, and this would occur whenever I switched the Conar voltmeter leads. In fact, I checked that capacitance with my LCR meter, and it measured approximately 0.001 uF capacitance. Would that mean anything? Oh yes, there was definitely 4,000 VDC between the magnetron heater and ground as I measured that with my high voltage meter. In addition, the magnetron overload protection checked fine.
There are capacitors within the socket from each filament lead to casing. When those caps breakdown and leak, that’s the resistance you see when doing the ohm test. New socket from Amazon corrects that problem.
Well, the only sure way of testing out a magnetron is to check to see that the required DC high voltage is indeed being applied to it.