Faulty Microwave Capacitor Diagnosis and Replacement 

Well I’m glad I’m not the only one who is wondering why he didn’t discharge the capacitor before removing it, and from what I was told it isn’t suppose to be tested with a digital multi meter either

I'm glad so many commentators are aware of the dangers involved in opening a microwave and the capacitor, it actually has a bleeder resistor built in, but they do fail and that's why, as many people have mentioned, that you should take two well insulated screwdrivers and short the contacts one at a time to the frame, then you can disconnect the capacitor, mostly at the shop we do these kind of repairs under warranty, not worth the labor otherwise, cheaper to buy a new one

how about putting the part about discharging the capacitor at the beginning of your video... Jeezus.

Thank you very much, Tanner!! I was about to throw this away, and I came across your video. Fixed!! And I love the jingle!!

You’re going to get someone hurt to put this on the internet and not show that the capacitor should always be shorted before going anywhere neat it. You poked your hand right onto that capacitor when you started. Your familiarity with these components isn’t what most people experience. Stay safe.

I have one that I think the thermal sensor is bad or the fan quit. I put it on reheat and just as it is finishing up the display goes out and then a couple of min later it comes back and says PF like it has had a power failure??

What were the original symptoms? Not heating? Lights and control panel dark?Mine seemed to be working but sounded loud and wasn't heating. Additional short attempts to heat - like 15 seconds at a time weren't working.....then I heard a pop, then all lights went out. Suggestions?

One of the handy parameters on the side of that cap is where is says "DANGER H.V." -- you should make note of that one.

That capacitor can kill, the internal discharge resistor should not be trusted, always discharge the cap yourself before you attempt a repair.

Dude! You are great at explaining the process but you should think about the safety of whoever is watching your instructional video. Not discharging the capacitor, standing on concrete in your bare feet with the electric cord from the microwave hanging from a water spigot could cause someone not familiar with the dangers of electricity to get seriously hurt or killed. I would recommend taking this video down and doing it over. It's very insightful. Thanks for the info.

Transformer making noise when I plug it in. Unless I open door. Also trips breaker. Checked door switches. Look good. Any suggestions?

Hi, my microwave does not power off but it does work, it makes a buzzing noise and will eventually trip the breaker. I am replacing the megnatron, do you think this is the issue?

Take care dude and keep safe whenever your dealing with any electrical or electronic device have a nice day

Really nice video thank you. So i was hearing up my cup of milk for a minute and suddenly after 30 sec i smelled something was burning. So i tested again and it did not heat up anything. I opened the microwave and removed the fuse and put back the same one and it was heating up the milk now but the smell increased this time from the fuse plate. I dont know I just need to replace the fuse or capacitor could be gone too?

Did your microwave start getting louder and making a humming vibrating noise before the capacitor went? Mine is doing this. I suspect the magnetron is starting to go in mine.

Thank you verymuch for engineering schematic diagram . No service person has shown rhis till date .

mine has a very odd issue, when its been working a while and lets' say either loses power in the house or comes unplugged for a hour or so, then comes on, none of the button work, they just beep, cant cook nothing, it has to have constant power for about an hour then the buttons start working again, kinda like a capacitor having to build up power first or something else, i dont know alot about them?

Thanks alot i just fixed mine

Thanks, good info.

I have a 2006 Sunbeam Chinese made microwave with a repeatedly blown fuse. The Capaciyor is a 2000V model and all the replacements via Amazon are 2100V models. What happens if I replace the 2000V model with a 2100V model?

Can this repair be done while the microwave is installed over the counter? I have an LG model lmh223dst.

Thank you nice video and info. please tell me that CAN WE REPLACE BAD MAGNETRON WITH GOOD ONE OF ANY MICROWAVE OVEN

Always short out the capacitor before doing anything .. Engineers have died that didn't do this first

Barefoot outside with shorts and t-shirt. Must be in southTexas or Florida. Can't wait for the weather getting like this here in Germany as well. Won't happen before May, that's for sure. It's so dull an miserable at the moment. Stay safe with mains and HV, please!

@TannerTech This is a great video. I have a question. Would you know which part is not working if my microwave turns on but is not heating anything? How would I know which part to replace and where to locate the part. The microwave manufacture date was 2002.

Nice video I look up to you

Thank you sir

*GREAT VIDEO* Now i'm gonna fix my microwave,stopped heating yesterday; I'll put 2 insulated screwdrivers(or one if it fits) across that capacitor...anyway...

Hi,,my microwave burn the fuse that comes from the capacitor so it doesn't heat the food could be the cause for it?

I have a question for you. My over rang microwave oven doesn't blow any fuses and I dont see anything burnt. Light works and exhaust fan, it also runs and heats great but only for about a day? Then it starts dimming the lights and kinda pulsing. Outlet is good! I'm trying to decide is the machine worth fixing if so.. what the issue. Thank you!

Is directly connecting both ends of the capacitor a correct way to discharge it? I honestly don't know but I presume it should somehow explode or at least show a nasty pop! It's written on the note that there is 5kV around the capacitor after all. That pop should be a nasty one.

Hi please help, the moment I close or open the microwave door the fuse blows

I don't doubt that you know how to repair this microwave, but you need to re-do this video for safety reasons. People not familiar with the danger of capacitors could be seriously injured or killed because they didn't discharge the capacitor. Don't ever assume it has bled off.

Very good 👍

Awesome!

they say discharge the cap before repair but one end of capacitor already connects to chasis through diode.. what is the point ?

Well explained sir Than q

Reading the comments: y'all the real heroes 🙏 as my instructor always says, "Safety first!"

Thank you!

Barefoot on concrete, working on a plugged in appliance.....are you trying out for a Darwin award?

Good testing with metering. My mw had some switches that needed replacing and now it works but the fans seems to not be working. Cannot be the fuse or capacitor. Never heard of a fan going bad. Maybe Mis wired

What would be happened if we replace the capacitor with the higher value ųF? E.g 1,3 ųF, would that be better or worse functioning?

I found this to be very informative, yes I see a lot of people on here quick to criticize you but it showed more info then most others I looked up, thanks for taking to time to do this video.

Thanks 👍

Good job Tanner. That is a lot of capacitors, where did all those microwaves?

Those microwave caps have got a nasty bite, hey :) great video as always mate .👍

Thank you, I learned a ton by your video.

Nice job, as always, Tanner!

Onto my 5 fuse retry. My high voltage fuse blew when it died. Replaced that, found the top fuse was dead, replaced that, then blew the top fuse again. Was lower A thought that was it bought the right 10A fuse blew again. Tried again to confirm (double check everything is in place). Time to invest in a multimeter.

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! Show less Reply

how important is the capacitor value? I have a replacement capacitor that reads half its rated value. would that work ? the original one reads 1.0 mfd. the aftermarket one reads 0.6 mfd. but labelled as 1 mfd.

Hey tanner, I saw you in the new make magazine with your rolling back pack. Good job!

What is that black spot on the board after you got shocked??😁

Is doesn't matter which end of the Capacitor the diode and the magnetron are plugged into as long as they are plugged into the same end and the Transformer in the other end, correct?

What caused that big black burn spot under the where the fuse is? It wasn't there before you shocked yourself.

Sooooo..., why did the circuit board get burnt? Was that from your shock? That's a lot of volts to do that burn. Thx

He probably should have marked the bad cap immediately with a big "X" so he wouldn't mistakenly re-install the bad cap. Especially because he had an identical cap in his pile of used caps. Just sayin' .

The chassis is ground its just the positive is grounded so like you said the magnetron receives -5000v reference to ground.....

the capacitor is just a high resistance dummy load resistor for the magnetron the diode (high frequency generator) the capacitor determin if magnetron is raised the current and it blow the fuse if you use a bigger current fuse or directly connected fuse if the main outlet is raised the voltage the voltage in secondary will also rised and burn your capacitor and magnetron

Hello on my microwave 5kv 800ma fuse, if replace with 5kv 900ma is ok?

Always always always discharge your capacitor first. Drives me mad when I see a safety rule missed out. I see it said in the description but not done on the video/

Great video with out the U knows,,,well done,,,have a GE that's not heating,,,is it usually the Capacitor? if so very inexpensive fix. The issue is it's a built in unit,,with a frame. I'll see what I can figure out,,,any tips let me know.

You had me at the intro brother 😂

... unless you want a real powerful punch in the chest or hands you must always short out a HV,... especially Microwave capacitor before taking and Multimter readings,... it will surely fry it!!! !Same goes for TV and computer monitor caps....Stay safe!

It was a totally shocking experience!

Why you did test the capacitor you replaced

Excellent video Tanner. Most Excellent. I had purchased a new capacitor for my microwave but I had hooked up the wiring backwards. You showed the correct way to plug in the leads. Thanks. It’s working fine now. Question: Why do you have so many capacitors?

He does say about discharging the capacitor at the end of the video!

Any additional jobs 4 capacitor

U forgot to show drain the capacitor before touch the microwave after open it. May I ask why there is a resistor inside the microwave AC capacitor? Can AC capacitor used to store DC current? Or they are not compatible?

Radio Shack Meter...wow, you had that for a while!!

a bit fast but very clear and educational!

Can't you discharge the capacitor with the volt meter and thus verify?

Mus it be the same model cpacitor

It even says "DANGER H.V." on it.

Wouldn't that cap show some continuity since it has an integrated bleeder resistor? The symbol clearly connects the two terminals.

Always discharged the capacitor ... capacitor may hold thousands of volts ... not discharging it could be dangerous

Why not use a multimeter that has capacitance test feature to make it more accurate? I see this one has 1.10 microfarads.

Why didnt you test the capacitor as a capacitor and not as a resistor?

Maytag MMV4205AA Built in literally smoked 1/2 of transformer... not sure why ..but since there is no transformer to buy to replace (2005 micro) came close on Ebay but did not match the: 6170W 1D00C on trans.........

really its gooo.

Perfect ! Ive got some microwave troubles and this seems to be the issue on my old machine from 1987 it just broke down . Buying and multimeter tomorrow and trying out what broken in the machine . Thanks for the tips and Tutorial ! Regards Paul Roger -North Sweden

Be careful, you should set the current limit on the power supply otherwise you will fry the diode.

I worry for you. The way you handle electrical components-especially the capacitor-tells me that I would not be surprised with you ended up dead with electrical shocks. Slow down, exercise some safety and have some respect for your safety.

1,1.05,1.07,1.10,1.20 microfarad.. all are compatible caps.. no problem to replace with these values..

what about the capacitor its charged

@05:03 why don't you test the replacement capacitor to show what a good capacitor looks like with your meter?

LOL, notice the black scorch mark on the board he replaced. 🤣

❤👏

Mine sparks in the middle on the bottom

everyone here seems to be well versed on this issue. I ordered a new capacitor to replace the old one the new one had different specs but didn't realize it the new one was 1.05 uf vs. the old one was 0.91 uf when I turned on the microwave with a coffee mug to test heating after replacement, after about 30 secons or so I smelled rubber smell stoped the microwave but still not heat, anyone can tell me if the difference in uF is the issue or is it something else completely! Much appreciated

Didn't short the capacitor. And used an old capacitor. Bad example for beginners. Ouch I just got shocked

slow your roll man. you are going real fast. great inf. but I cant catchup

If the diode has continuity does that mean it's still good...fuse is good ,and capacitor doesn't have continuity.... So it's good also.. thanks

IMPORTANT!! DISCHARGE CAPACITOR FIRST FOR SAFETY!!

A capacitor can’t take 2kvac and convert it to dc and ramp the voltage up to 4kvdc. That is just not a thing. A capacitor is neither a rectifier or an amplifier. You can use it as a filter to block high frequencies in ac but you will not get dc out of it no matter the spec

EEEEE...I can't watch this, my co-worker forgot to discharge a cap like this and got zapped, I saw it happen.

👍👍👍🙏🙏🙏

Yes, to avoid injuries, you have to discharge the capacitor first. You can do that by touching both ends of the capacitor terminal simultaneously with a pair of insulated long (needle) nose pliers, but be very careful not to touch the metal portion of the pliers though. Here's how to do it here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-OEet8SKsRc4.html And see what could happen to you if you skip that step: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-A9yvUbWetXM.html

Capacitor Discharge. If someone follows your video and they are shocked you may be in for a shocking surprise.