Microwave Magnetron Test - Good vs Bad

Simple way to test your microwave magnetron, comparing a bad one with a new one.

[@ErikMiddeldorp]

I've just replaced a magnetron and they both measured exactly the same, zero conductivity between the terminals and case and basically zero ohms across the two terminals. So measuring low ohms across terminals and zero conductivity between terminals and case doesn't necessarily mean the magnetron is good.

[@deangelocesar5666]

Instablaster.

[@johnnyquick7128]

Had the same problem. Could not find anything else wrong with the microwave. Took it in to have it fixed. Magnetron was still bad. I did ask the tech how he tested it. He said they used a high voltage probe to test it.

[@domino4.69]

My 3 y/o GE microwave recently stopped heating, checked everything (diode, capacitor, 3 switches, etc.) - all passed the test, but upon inspection of the magnetron metal radiators, I noticed some slightly burnt surfaces including some part of the metal housing but again it passed the test like the video described here. In the end, I replaced the magnetron with the new one. Now, the microwave is working again.

[@imageskj1]

Mine too! A PEB7227SL. I lucked out and found a brand new PES7227SL (Stand alone model) at Nebraska Furniture Mart which I was able to modify slightly and fit into my built-in.

[@AznTony360]

How to check a microwave magnetron: check everything else. Door switches, fuses, relay, transformer, temperature sensors, high voltage capacitor and diode. Why? Cause you’ll know for sure those are bad with just a multimeter and a 9v battery. If all those test good, it’s the magnetron. You cannot test a magnetron with just a multimeter. There’s a possibility that it’s still bad regardless if it tests good from what’s shown. Picked up a junk microwave to flip for cash off criegslist. It didn’t heat, and everything tested working even the magnetron. Ended up getting another junk microwave, after testing all the new parts, started swapping in the working parts. Ended up swapping the magnetrons. The first microwave started to heat again. The 2nd junk microwave only had one bad door switch. First junk microwave, everything tested working, or so I thought. Lucky since the some microwave parts aren’t cheap, hv capacitor, transformer and magnetron to be exact. One of them fails, means you need to fork over 1/4-1/3 the cost of a new microwave.

[@rileyjones7231]

Holy shit, the amount of people on here complaining about covering the readout on a SOUND continuity test is infuriating. These people shouldn't be allowed to take their microwaves apart.

[@corrinepascznk3710]

That was excellent thank you very much. We were able to determine that our magnetron was bad.

[@HariKrishnan-ed5sz]

Excellent explanation. Very helpful thanks bro

[@micahnoirot26]

Hello, I'm testing my magnetron and i keep getting .2 ohms and then I also get 0 it might start reading .2 -.3 but then it drops to 0 , when doing the first test. Bad? But when doing the last 2 , everything shows good. Thoughts? Thank you!

[@philipballou]

This is misleading. You can have a magnetron with perfect multimeter readings and still be defective. You should at least mention this in the video.

[@jonnieringo7758]

humpty mine past the tests but on visual inspection, the magnets were broken in half and a gentle shake produce some rattling sound.

[@fcallum77]

My dad had a cheap microwave from a supermarket chain, here in England. It was only £30 brand new - I'm going back 5 or so years. The magnetron had failed but it was £25 to replace it. The microwave went in a box. Some day, I might be able to get a cheap microwave and have it back in service.

[@brianperkins6121]

Allways inspect the magnets and make sure there not cracked , and look at the tip of the magnetron (Its Antenna) to see if its been damaged, Allways remember the ouptut of the microwave transformer the Capacitor and high voltage diode are in an extrermly high voltage an high current voltage doubling circut and use proper respect when working around them, there are some cases where the Capacitor can hold a deadly charge even when the microwave is unpluged (Allways assume its charged), those leads are connected to the magnatron and you can get hammered when you try and remove them. The Capacitor "must be proven safely discharged" before removing those leads ..

[@SuperGinki]

My understanding is that when the microwave pops when starting up it could be the magnetron? How likely would that be? We had a short power outage and now it occasionally makes that loud popping when trying to heat something up.

[@venox48]

What if mine showing 0.03 and then after a while it shows 0.02 , 0.01 and 0.00. It indicate bad magnetron or just it is multimeter dependent ?

[@iranfreedom12]

Mine was reading all ok and according to your test and there was no sign of physical damage as i was sure and had tested transformer, diode and capacitor i went ahead and replaced magnetron and it fixed the issue, so it can read all ok yet be defective.

[@barbaragoralska2503]

I am sorry but you do not know how to work with multimeter. Your COM port is unplugged.

[@KABOZSKIE]

Thanks for sharing this sir. Last question do ypu have supplier for magnetron?

[@HanryYesui]

I have removed the magnetron and realized it appears to be defective at the very tip as it has a small burned spot. I also checked inside the microwave where the magnetron head is inserted into and it also has a burnt spot. I tested the magnetron with a multimeter and it passed and the diode and capacitor also pass. I have not tested the relay yet because as soon as I saw the burnt spot on the head of the magnetron I am guessing this is the problem but I want to ask what you think and whether you think the burned spots on the head and inside where it inserts into indicate the magnetron is the problem or could it be something else?

[@qweqwe700]

Exactly what i was looking for and short and sweet to boot, thanks

[@Rathin_Tewari1988]

sir magnetron coil showing 1.3 ohms its a faulty coil?

[@C.Veigas]

Mine is giving 0.2 / 0.1 and no continuity to the case. Is it good?

[@yuryran8936]

your hand blocked the display of the meter

[@colejohnson1960]

Dude, your blocking your readout. Video is useless.

[@vollieoberholster]

Remove your hands so that we can see the readings on the multimeter

[@maces1405]

You sir are a legend! FYI if you own a Samsung microwave. The magnetron has a ten year warranty.

[@lithium98]

I think mine just went out and my 1 yr warranty expired a few months ago. If this applies, you just saved me some money!

[@jaclynvangilder7823]

I had a microwave with no heat. Magnetron sounded loud. It measured .2 ohms across the terminals. Then went to zero after a few seconds. The new Magnetron did the same thing. The new one worked in the microwave. The terminal resistance and terminal to case test if passed does not necessary indicate the Magnetron is good.

[@TheRainHarvester]

How much was your magnetron and where did you buy?

[@imanguha5244]

It's been a long time, though I am replying, in your case, the magnets of the Magnetron might had broken, that's why everything looks good but didn't work.

[@listerdave1240]

There are typically four ways a magnetron may fail. The test in the video can find two of these faults but passing those tests by no means guarantees the magnetron is good. What the test can find is if the filament breaks and if the filament has sagged and contacted the anode. There are two more ways it can fail. One is that air leaks into it so it no longer has a vacuum and will arc inside instead of making microwaves. Such a failure will not show up with the continuity check except in some cases where the arcing inside the magnetron has melted something and caused a short circuit to be created between the cathode and the anode. In that particular case the continuity check will show the fault. The other, much less common fault is that the magnets lose their strength. That usually happens because for whatever reason the magnetron would have overheated and the over temperature cutout didn't do its job. With this type of failure sometimes the oven is just much less effective, still heating somewhat but much less than it should.

[@scottk27332]

Awesome reply. My Panasonic micro is showing H98 code. The magnetron shows continuity terminal to terminal and terminal to case on both. I'm assuming that is not how it should read and had shorted.

[@scottk27332]

@@BlondieSL If it's a short of any kind, I would advice replacement. My understanding is that these are not serviceable and I wouldn't want to risk a questionable fix at the frequencies these operate at. Replacing my Magnetron did the trick for me.

[@listerdave1240]

​@@BlondieSL The short answer is no. The longer answer is that it is possible but difficult, requires special equipment and not worth the effort. The short is usually caused by the filament sagging and touching the anode. You would have to cut open the tube, replace the filament and then evacuate the device and re-seal it. The last part is the most difficult and needs specialised equipment the bring down the pressure low enough for it to work. Commonly available pumps such as used in the HVAC industry do not create a good enough vacuum.

[@Frty47]

@@listerdave1240 Crois moi le jeu n'en vaut pas la chandelle !

[@NashPotatoesOutdoorShow]

Very helpful...thank you!

[@rosekile318]

Helpful video. However, it would be even more helpful if your hand didn't cover up the multimeter display during the tests. Thanks for taking the time to post the video.

[@rileyjones7231]

What part of sound continuity test makes you want the readout? Continuity either exists, or doesn't. There is no need for a readout

[@paulkolodner2445]

Putting your hand in front of the meter display masks the most important information.

[@KSparks80]

Are you blind? You can read it for every test he did, ffs!

[@paulkolodner2445]

@@KSparks80 Damn, you're right. I have seen other videos about these tests where the important visual information was blocked. Maybe I got them confused. Now where are my glasses....

[@rafaeljeveaux5322]

totally helpful here, thanks a lot for sharing this

[@philiproberts92]

My magnetron is reason 90 ohms terminal to case is it functional or should I replace it, the diode on the capacitor was bad. I just don’t want to put the microwave back together if the magnetron is bad too

[@nafunny3606]

IT'S NOT 0.2 OHMS, that's the resistance of your leads!!!! zero out your leads when measuring such low resistance devices.

[@hiemabedrog]

An LG 2M246 magnetron can be used as a direct replacement for a Samsung OM75P (31) magnetron even though they say you CAN'T, LG parts is cheaper than Samsung.

[@kevinkeeler2764]

Why dont you get your hand out of the way

[@nyorkennethsandot2068]

what if there's a continuity between two terminal ? is it good or bad ?

[@RickBardos]

That's normal

[@PeopleHealthTru]

@@RickBardos Another guy said 0 ohms between terminals is bad. yes?

[@adamputerla2309]

Oh, how naive and childish

[@rileyjones7231]

So the magnetron is supposed to be near short circuit resistance?

[@ranjitkumermodak5280]

Hello friends. My microwave oven does not display power. When the oven door is opened, the rotation motor is driven and the lights are turned on. Nothing heated while the display was in good condition. I don't know what the problem is. Advise or help me.

[@padony4710]

some magnetron have faulty magnet,.. even its have a good resistance..

[@renebcastillo]

Position your multitester higher we can't see insted but your hands.

[@appliancedude63]

Simple

[@asiawaqarahmad6207]

hi I checked one magnetron .that shows continuty short circui in between case and terminal .and in between both terminals resistance is .4ohm. also hv fuse was blown . so magnetron is faulty? hv diade is good .I checked it too

[@RickBardos]

Asia Waqar Ahmad you should not have any continuity between the magnetron case and terminal. This would indicate a short which was the same problem with mine.

[@asiawaqarahmad6207]

Rick Bardos thank you.

[@TheRainHarvester]

@@RickBardos , does this rule apply to all magetrons? Where is a good place to purchase?

[@Slim-Pasty]

The magnetron in my SANYO, tested above 5 ohms, between the two terminals.

[@charlesfreeman3833]

Thank you! Nice video.

[@tristramo3760]

On my combi oven the microwave only works if I have first warmed up the convection oven. If it starts from cold the microwave resets after 3 sec. I replaced the magnetron but same problem. Any ideas/suggestions please? 😀

[@bscgvrvr]

Iam getting continuity Between power terminals of magnetron is it ik

[@PotatosPotatoes]

You just saved me from buying a new microwave! I had tested it and gotten the right ohms. Was about to buy a new one and found your video. I removed it and it was rattling. Thank you!!

[@neillourens5387]

I have a question, my magnetron did not work. Readings on the old and new one exactly the same. Between terminals and between casing and terminals. How is this possible, yet old magnetron not working????

[@sergeyv83]

on the left one you said is a bad one but the bad one is the right one. Confusing

[@abdulmuqsittofie949]

In this instance it's most likely the filament terminal capacitor/socket that's bad. That part of the magnetron is replaceable and can save you alot of money

[@marklatting5691]

It does thank you. Every need advice on hvac/r let me know

[@spalkin]

What if there's absolutely no reading when checking resistance across terminals? I don't even get the .3.

[@francomattei9545]

I see your hand and not the DMM

[@KSparks80]

If you can't see the display for every test he did, go see an eye doctor cos you're blind as a bat.

[@AMPFIXBISTAGTV]

hello thanks for that guided digital test

[@luisfercr2447]

Very simply put! Thanks! It helps a lot ;)

[@prasanna29111967]

Nice explanation Thanks!

[@Keithers_]

Thank you. I'm trying to figure out why my microwave keeps blowing the fuse every time we try to heat something up, so I will test the magnetron.

[@asifrana5392]

Nice video and info. please tell me can we change bad magnetron with good magnetron of any other microwave oven or we have to purchase magnetron as per real number or model .

[@dr.rahulverma3038]

excellent video but transformer se dhua nikal raha hai please reason bataiye

[@shahajadali8561]

Wiring ulta ho gya he sayad

[@cinemastationforall4562]

i like your video

[@swedensy]

I got 0 Ohms between the pins. What now?

[@JSuparman]

it okay. actually small resistance exist, but your ohm meter cannot recognized that small value.

[@bethpersons7134]

Thank you for helping the novice

[@omar-qe6dy]

You just saved me some time, thanks for taking the time to make this video.

[@davidgalvez1882]

What If you get a 2.5 reading on the terminals?

[@custodiodsouza6162]

What rubbish cannot check by multermete

[@gkherbalexports9789]

Meter reading not visible

[@freecheese4143]

Good video. Smart way to check it.

[@davem3789]

This is exactly my situation. Thanks for the video.

[@zer0b0t]

says left, tests right, confused me a lot

[@stupersyn1]

Does the magnetron need to be removed from the mocrowave in order to test if it's bad?

[@RickBardos]

No, just disconnect the wires.

[@stupersyn1]

@@RickBardos Thanks! The filament where the wires connect ended up being fried, I have continuity to the case

[@hotlava2222]

if i get a ohm reading on the "lowest" ohm setting from point to case? I get 125 ohm

[@picanazo420]

that means your magnetron is burnt, for a good magnetron the measure resistence betewn point and case must always be infinity, otherwise its burnt, there is a way you can repair your magnetron, search at youtube, there are few videos of repairing

[@sufianag5790]

Thank u so much. I ve easily fixed my microwave using ur instructions .. Thanks again

[@taharchowdzdz1248]

Your hand plase

[@mjafar1981]

Hi. I have a i3 turbo chef I replaced the Magnetron it would run about 10 to 15 seconds and turn off can you help me

[@TheRainHarvester]

Sounds like a power supply problem. Maybe the capacitors in the power supply?

[@augustinechinnappanmuthria7042]

Super 💖

[@barryburke5782]

My GE Profile Microwave worked for about 5-7 seconds then shut off. Further exam revealed burning/sparking in HV Inverter/Transformer. Digital continuity checked OK for all door switches, primary thermostat, shut off fuse, etc. Replaced Transformer with new part. Everything worked fine except 'No Microwave Heating'. Next, replaced Magnetron and Relay Switch on the circuit board. Everything worked fine except 'No Microwave Heating'. Magnetron humming seems normal! Cleaned mica wave board inside of unit, no sparking here. Can anyone advise what the problem may be. Again, everything worked fine including settings for time, power levels, clock, etc. when started up except 'No Microwave Heating'. Last resort before dropping out to the curb for the landfill! Any ideas greatly appreciated! HELP!

[@TheRainHarvester]

Did you ever figure out how your microwave was bad?

[@coryplants1264]

Make sure it's not in demo mode

[@ziadfawzi]

Thank you.

[@tanveerhadi7656]

Kindly tell me any one how remove the convection fault

[@sanchesk835]

Awesome thanks 🙏

[@347mrjnk]

Look like a short

[@Elwinator3]

Does the Mag have to be removed from the Microwave Oven to test it?

[@RickBardos]

Not necessarily, just be sure the wires have been disconnected.

[@kaleemyork]

Dear , i checked as per your idea my magnetron is good but still there is no heating, checked transformer, capacitor, diode, and input voltage of transformer, please help me if magnetron is ok then why no heating,

[@youiker]

Sometimes the megnatro pass the test but it's bad, you have to buy new megnatron

[@bobwhammer4237]

Check door switches

[@kwsa4657]

very very nice

[@tipan172]

Hi Rick, I see your hand is good test, i will do my hand also. LOL

[@KSparks80]

Make sure to push probe deep under your fingernail to get a good reading. It may sting a bit, but that's ok. You should get a good reading. Next, plug the unit in to check the capacitor to be sure it has the correct incapacitance. (Be sure the capacitor fluid level is at the "full" mark first. If the mini dipstick is missing, you can make a decent one using a safety pin, a small piece of scotch tape, and a 24 volt/60 amp battery charger with a "start/boost" setting). It should be self explanatory, but if not, find someone who can do the test properly. It'd be easy to knock your dick stiff and burn the hair off your head if you mess up. Safety first!

[@PLCDMC1]

Helpful but HANDS!!!!!!

[@sanjeewaelectronicmahiyang9617]

hey

[@iloal100]

Que bien se te ven las manos

[@zeeshankhan-ib6zi]

Thank you sir

[@eyeringed]

Your hand covering the meter.

[@rileyjones7231]

The meter readout doesn't matter on the continuity sound test. Sound = bad. No sound = good. Meter readout on sound setting = useless

[@abdelkaderelbachir9523]

Thank you so much in fact that was very helpful 😌

[@TECNOSERVICEfull]

👏👏

[@Kopanadidikharianto]

thanks sir …

[@freemy3301]

ขอบคุณครับ

[@albertsekantse9963]

Thanks sir

[@zekachacon]

nosense

[@rachelrabe6649]

sadly you didn't check your video and the meter readings could not be seen due to hands being in the way, but useful information, thanks

[@Rathin_Tewari1988]

ur good sir

[@asathaltamil]

super sir ,i am u videos my useful

[@amalrasika]

How to repair magnetron Microwave Oven troubleshooting capacitor check diode transformer

[@boogerhead0]

This is not a definitive test set. I have two magnetrons here that test fine by the video, but neither will heat. Replaced with new units, both microwaves work perfectly, so I know it's not, otherwise, something else in the HV section.

[@RickBardos]

boogerhead0 That's true, these tests will verify continuity across the terminals or identify a short with the housing.

[@boogerhead0]

Yes, but not always cull out a bad magnetron.

[@boogerhead0]

What are other tests that will absolutely cull out a bad magnetron? I have two that pass the shown tests, but don't work. My question is "What is truly wrong with the non-working magnetrons?" The ring magnets are not broken, and there is no other apparent damage to them.

[@voodew-nomad4715]

boogerhead0 could be the relay or the board itself , these are the ways to test magnetron, yes it’s not fool proof however it is the only real way , What I do is disconnect relay with micro off and then on to test continuity , of relay if it don’t then I use a wire to jump the relay wires , to see if bypassing relay makes it work .. if it heats I know it’s the relay ..... if it don’t .... then I need to measure the voltage of relay while on to see if the relay is even being powered .... if not the the board needs to be looked at ...... it’s all about sequence of operation..... u plug it in ... you have power to switch ... turn on switch you have power to next thing .... is that working if so keep digging further ...if so you ,found the issue ..... only exception is the boards , they will lead you astray if it’s an occasional board issue , and have to rely on experience to get that feeling it’s the board and not the 4 issues you found getting to the board ..... can be done just normally way more time consuming

[@sdas200]

@@voodew-nomad4715 sir not clear, which one is relay & which board do u exactly mean..

[@impracticalwill2771]

Does magnetron has a polarity or if I connect in reverse will it blow up and is there any way to find its polariry