Trying to FIX: Panasonic Microwave Not Heating
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- เผยแพร่เมื่อ 21 พ.ย. 2024
- Hi, in this 'trying to fix' video I attempt to repair my faulty Panasonic Microwave NN-E225M. The microwave turns on with a light and spins, but no heat is produced.
Extremely high voltages are present in a microwave so do not copy anything that you see in this video.
Remember that this is just for entertainment and I am not an expert in these repairs. The processes in the video may not be the best way, the correct way or the safest way to fix these things.
I do love fault finding and trying to fix broken things so I hope that comes across in this 'Trying to FIX' series.
Many thanks, Vince.
this channel is going extreme. first, high blood preassure, now high voltage. please take care, Vince. we'll need you when the world ends, to put it back together
Any charge left in capacitors in a unplugged device will always be DC, Vince. The capacitor can't alternate the charge by itself.
Vince is a far braver man than me! I would have been deterred by the high voltage warning sticker.
Hey vince, just a couple tips- when you check a microwave capacitor for continuity across terminals, you can switch to ohms range and check for a bleed resistor as many times there is a 1 meg resistor built into the capacitor. Dont rely on these however, as they can fail. Also, multimeters in general do not have enough forward voltage to check microwave diodes like that which is why you had to use a battery, its not just your multimeter. Great video.
This sounded like a Photonicinduction video when you said 'its been on fire twice!
Glad you survived venturing inside the microwave; many years ago we had a Sharp microwave, used regularly for about 15 years, then one day the large diode failed spectacularly with a huge bang which shook the kitchen!
My dad decided to repair it, couldn't get a suitable replacement diode, so he got about six smaller diodes & soldered them in series to make up the value & fitted them in the oven, it worked for another 5 years after that, eventually the magnetron failed, so we bought a new oven.
The price of the replacement magnetron you showed is a rip off, same price as a complete microwave!
Dear Vince,
Thank you for making this video. I have almost the exact same microwave in my apartment I am renting and one day it stopped working. The problem was the same as yours, it worked but did not heat. Fortunately the magnetron in mine was fine, only the fuse blew up. So I ordered a new one and have just put it in and now the microwave works. So thanks to your video (and a couple of mechanical blogs) I had the courage to take a look and I was even able to fix it by myself. I learned a lot from your video, I am really grateful to you. Take care.
When purchasing a new microwave, Vince, aim for an inverter microwave. I bought myself about 2yrs ago now an LG Inverter microwave, went for a 42L one (I live alone but the big size allows me to do pretty much anything in it), 1200W inverter.
The model number for mine is lg-MS4296OSS. Cost me 299AUD which would be about 150GBP, but worth every cent I paid for it.
It cooks more evenly, and faster.
Also, at the beginning of the video when you showed us that it was spinning, you should never run a microwave with nothing in it, all that microwave energy has to go somewhere, and normally it goes into what you are trying to microwave, however if you have nothing in there, the energy will just go back into the magnetron, which will reduce its lifespan.
Hey Vince. I know this is an old video, but here are some tips.
First of all, the diode is not faulty. A high voltage diode will show open circuit both ways on any multimeter. An easy way to test the high voltage diode is using a 9V battery. Check it on one polarity, and should have 8V. Flip the diode, should be any voltage.
Then for the magnetron. Im pretty sure the magnetron is good. What usually fails is the connector of the magnetron. Yes, that white plastic piece. There are some components inside that connector (if I remember correctly, some capacitors). They are common for shorting to chassis ground. You don’t need a whole magnetron, you just need the connector and replace it. Behind the magnetron cover there are 2 coiled copper wires. They’re connected to that connector. Just cut them, remove the connector and replace it with a new one.
Greetings from Colorado! Love your videos. My parents owned an appliance store growing up and I used to fix a lot of microwaves. Regarding the mystery switch that seemed to do nothing, it's a safety interlock switch designed to interrupt operation if the position of the two other door switches are not in agreement. It's basically a safety feature designed to disable the unit if someone was trying to defeat the door switches by manually holding them closed with a screwdriver. It's a sort of "logic puzzle" circuit but makes a lot more sense if you see it on a schematic. Also, chiming in, but that capacitor is super dangerous. 😋.
Brilliant, perfectly explained. Thanks Eric :-)
I fixed the microwave from the kitchen at work which had died, it had a blown fuse. Looking at the circuit diagram which was conveniently included, I worked out that it's designed so that if the switches get out of whack, so something funny is happening with the door, it will just dead short and blow the fuse..
After replacing the fuse, and closing the door very slowly and gently, I found that it would cause it to trip..
The fix was bending the thin piece of metal that the plastic bracket holding the switches is mounted to, to realign it with the door.
This is one repair that I've done before. Friend of mine asked me if I could fix her microwave. I told her that I've never tried, but let me check. Like you, I went on TH-cam and found they were quite repairable. I told her yes, but I thought she was probably better off buying a new one. The one she had fit over the top of a stove, and she was certain it was not a standard size. I measured it and it was a standard size, but she insisted I try to fix it. Ok, so I had her order up the diode, capacitor, transformer and magnatron (I wasn't gonna wait weeks in between part orders and I wanted to use the new parts for reference parts, and all parts were returnable) Came to about $88.00 total in parts.
So, with the parts in hand, I tested the diode (I used an old 12v DC transformer for forward voltage), Capacitor (tested capacitance on my meter), Transformer (continuity and resistance test), and all passed. Only thing left was the magnatron. I didn't know about the continuity test for it, so I just replaced it. That fixed it! It was about $45.00 for the new magnatron after all the other parts were returned.
There were two things I found: 1) I think her niece, who lived with her for a while and was a lazy slob, would warm up lots of takeout food, and would leave it in the carton with the metal wire. I think this caused the magnatron to fail. 2) I found lots and lots of food grease, probably years old, quite thick, and worst of all, it smelled HORRIBLE. It got on my hands and I kept smelling it for a week. I got some citrus degreaser and it took me about 1/2 hour to clean the thick, smelly grease. I would have taken a popcorn burnt one over this. Also, the worst burnt smell I've even had was one of my college roommates burnt his chocolate chip cookies in MY microwave.
Thanks for doing this video. I have the same microwave oven that I've been fixing but want to keep it so have been determined to fix it even though as I also found it's crazy that brand new ones are indeed cheaper. But I'll do my bit for the environment and re-fuse it as indeed my fuse went as well and the magnetron got a bit old so changing both should give it another ten years all being well.
Probably someone already mentioned it, but:
The spring in the fuse is to quicklyincrease the gap between the fuse ends so with this high voltage the spark will immidiately discontinue. With a normal fuse the spark can remain overcomming the gap between the to ends and cause a fire. So Never put in a normal fuse with High voltage parts.
By the way: Thanks for a good video on this subject.
@9:56 "What's that microswitch doing...?" Says the man who has never worked on a Turbochef oven. All of the interlock switches must engage at the proper time in the proper sequence. If you change a switch, you have to time them. Love your stuff, mate!
If the switches do not engage when they are supposed to, it will create an intentional short and blow the fuse.
@@jerryspann8713 There's usually three microswitches in the door interlock and if you force the door open without pressing the door open button they put a short across the supply to take out the fuse on the mains input panel. Fixed a neighbour's microwave that kept blowing this fuse due to one microswitch's mounting being slightly distorted. I used a bit of ali angle to make up a new mount and all was well.
20:59 - Megatron - that's a whole different kind of Transformer!
Is that the same as a magnetron?
I kept the transformer from my last broken microwave. It is now a quite nice and compact little desktop anvil for doing right-angle bends or straightening stuff out. It's also perfect as a nice heavy object when i need to glue something and put pressure on.
26:12 A facepalm moment when you switch hands AND switch ends so that the red lead was always on the screw end of the diode. So you didn't test both ways in continuity mode. It didn't make a difference in the end as you got it right later plus the forward voltage was too high to measure anyway. I guess that sort of thing happens when you are trying to troubleshoot and make a video at the same time.
Haha, oh no, I didn't notice at the time or during the editing, can't believe I did that!!!!!
@@Mymatevince hahaha, so relatable
@@Mymatevince I noticed the same, you left the red on the screw end both times. I was interested to see you check it once removed, but showed faulty. It is usually just the fuse, Ive changed a few without any problem ?
Either way, standard multimeters can't test higher voltage diodes anyways. I believe standard dmms top out at 1v for diodes.
My Mate VINCE Everybody makes Mistakes
If you're not getting power to the Megatron, it's probably because Optimus Prime has been there already =D I hate Microwaves, they can be dangerous. Whatever you do, never test one partly disassembled - all the switches and shielding etc are key to making them safe to use. I've always just binned microwaves when they fail - as you found they are usually more cost effective to just replace. Things are different if you buy a top of the range microwave etc, then it might be worth repairing.
One shall stand, one shall fall.
Haha, I knew I heard that name before 🤣, it rolled off the tongue so easy. At least I learnt about the nice little diode 9V battery trick. Just been informed that the Megatron can cause berylliosis so I am glad I didn't open it up. Hope you're keeping well :-)
Microwave capacitor usualy store more than 2000 volts. At least wear gloves, even professionals die from the shock of these capacitors
Yes I never understood why plain rubber gloves are not required equipment when working with high voltage electronics. Even with consumer electronics stray charges from the skin can damage sensitive components like mosfets and such, so it makes sense to always isolate as much as possible.
Emanuel Avelar I bought a 20,000 ohm resistor to drain the capacitor on mine. I learned a lot about microwave over components and working on microwaves by diagnosing my microwave over and repairing it.
@@keithwhisman Small, yet salient point, uF is capacitance, resistance would be measured in Ohms.
Crash Override you are right. I’m on tranquilizers and pain pills to sleep and my mind was a little foggy. Embarrassing it is, will change.
@@MirceaPricop
Plain rubber gloves don't protect against high voltage!!!
Does it make sense to pay more for parts then for a complete new microwave? Normally no. But this is the My Mate Vince channel and we all want to see you fix it and here how happy you will be about your success. ;)
Magnetron died and blew the fuse. Well done. Never done a microwave before and you cracked it first time. 👏🏻👏🏻👏🏻👏🏻👏🏻 but now we know why microwaves are dumped all over the planet as it cheaper to get a new one.
Well this was a dangerous one i'm just glad nothing bad happened and caused any damage microwaves are a dangerous thing to work on when they go faulty.
Hi Vince, I love watching your videos, I've just had to replace both heating elements on my electric oven, which I've never done before, not best for your oven to go down in the middle of a lockdown. I must be picking things up from you because I even tested the elements for continuity before I replaced them and tested the new ones for the resistance value and continuity both before and after I'd fitted them. I go into these fixes now with a "how difficult can it be?" Attitude. Keep up the good work.
I have been watching you for years and I have never been more worried for you like I was with this one
Haha, I was very nervous on this one until I knew the capacitor was drained. Then it was fine :-)
good logical problem-solving. As you did I would have checked the fuss first, then see what made the fuse blow. Love the diod trick...I did not know that. So thanks for the vid.
Exactly why My Mate Vince is my favourite subscription! Looks like I'll be testing the HV fuse and the Magnetron, etc, to get my 15 yr old Sharp up and running again... your videos have a lot of style, Vince!
If you haven't tossed this yet there is a TON of useful parts inside a microwave.
coondogtheman1234 I noticed that as well.
I'll be making an electronic rat killer with my old one soon.
Ohh? we actually gonna have an real life stargate soon?! :D
The transformer is a nice thing to have because it's a compact heavy object (i use as weight for glueing stzuff and as a tiny desktop anvil). My last broken microwave was very cheapo with a mechanical timer and a nice bell. Quite a nice bell, actually, and frankly the only quality part in the whole thing.
@@ReneSchickbauer I have two mechanical timers from a dead toaster oven. I plan to build a box with a plug and timer for my soldering iron and hot glue gun so it shuts off if I forget to unplug them. I've left my glue gun plugged in sometimes for too long and it popped and also popped the breaker.
You know the end of the Star Trek movie where they need the transmit codes to save the day, yeah it was Vince that had them.
Vince, it's the covered fuse without a doubt - It's happened to me with two microwaves - both times the microwaves operated as normal but they wouldn't heat anything, I changed these fuses and both worked like new.
Hi Vince hope you and youre family are doing well. I was not actualy annoyed that you didnt fix it im just glad you didnt get shocked. By the way Vince great video. Take care.
Thanks Fredy :-)
Just repair your old friend the microwave it accompanied you many years ! If the part's not cost much is definitely value to repair !
If you have access to a second meter, you can use it to test the voltage and current your main meter supplies when testing for continuity and resistance. I've found that helps me quite a lot in understanding what to expect when I'm testing components.
If you buy the new microwave, I would definitely suggest considering what parts you can salvage from the old one. The tempered glass platter can be put to good use in the kitchen as a carving or serving platter, and the transformer can be very useful for building and experimenting, for example! :)
Hi Vince,
Nice work tackling this one but please note they are very high voltage and radioactive, when I worked for Whirlpool/hotpoint we used a megger tester 500v for a insulation test and if the readings were high/short we would disconnect and test again to pin point the issue. But after checking the micro switches. The magnetron is measured by resistance not continuity test. The popcorn made the inside to hot and if there was a fire surprised the thermo cut out on the top with brown wires going to it didn’t blow/it pushes in on the other side.. test that for continuity.. also that fuse its the high voltage fuse 5KV possibly not sure as I never worked on a Panasonic microwave before but looks like the secondary side of the transformer going to the 0.82 microfarad capacitor running at 2000-2500 Volts AC.
Also it’s probably better in the long run to get a new one as if anything goes wrong the manufacturer will repair or replace it. Just get the extra warranty with it.
I appluad you Vince for your bravery opening a microwave. This is something I would definitely not do. Great video as always.
First time I ever thought I'd see the headlines...youtuber in shocking death pissing about with a microwave....lol
OK so apparently it is a capacitor (one of two) in the magnetron which go leaky to ground, they are built Into that connector bit on the magnetron(white female bit which the green connector goes into) , you can replace just that connector with the caps in apparently.
Magnetron dust from the ceramic is pretty bad stuff. Be careful if you try the cap swap that you don't hurt or scrape the ceramic bit.
@@saddle1940 Yes the ceramic insulator in the Magnatron contains beryllium, if it breaks & you breathe in the dust it can cause lung cancer.
All diodes have a forward voltage. Essentially a diode only starts working once the threshold voltage is reached. Your meter will have enough voltage to enable smaller diodes but as you have learnt, a high voltage diode requires more oomph to get it going. The 9V battery trick is the way to go about it.
With a Vf of 2.1V it's got three diode junctions in series.
Just wanted to say a big thanks for all these videos especially in lockdown- probably like a great many people I am consuming / binging on your videos and find them excellent mate. Hopefully soon things will start to return slightly more to normal but for now thanks for the new videos! Stay safe !
the black round with 2 wires is a temperature switch. they sit in almost everything. toaster. washing machine. dryer and more
great video
Microwave, getting adventurous now Vince
THE KING OF TECHNOLOGIES!!
I recommend salvaging the transformer, as you can use the high voltage to create arcs, and you can remove the secondary coil to make a high current, low voltage transformer for things like spot welders
I just had this same project when our expensive microwave quit heating. I checked everything and all tested good though I noticed the tip of the magnatron looked really cooked. Prices were sky high for new parts so I bough the biggest and cheapest used microwave I could find. I swapped out the magnatron from the donor I bought for $20 found it didn’t fit so I did some cutting and drilling and made the new magnatron fit and it works perfectly now.
Really enjoyed watching your video. Good diagnostics that leads to proper economic decision. Question: I assume you just threw away the old microwave or do you guys recycle somewhere? 🤔
Very 'brave' of you to attempt a microwave fix. Very 'brave'!
Love the videos :) especially fixing switches
MEGATRON: TRANFORMERS. Nice one Vince. Smart playing it safe. Interlock switch causing a short for safety reasons(watch 12voltvids). I did not know about the fuse on the transformer. Very informational.
Vince, I had to laugh. At 25:50 onwards, after you unplug the diode, you test it for continuity. You have the positive in your left hand and test it on the screw end of the diode, then you 'change leads' (red from left hand to right) and still use the red on the screw end and still no reading. Twice you do this. lol. Then you test for ohms and do the test the right way. lol
I've been in this a couple years ago, BOSCH combi micro 23 years old with already fan and magnetron burned in the past, this time it blew the 220V fuse every time we tried microwaving something.
Looked upon some videos and learned a ton of infos, turns out the old HV cap started phisically leaking oil and blew out shortly after, it wasn't too much of a standard cap either at 1.2uf (usually they go from .9 to 1.1 now) but I find one in Bulgaria brand new for cheap and the old micro (which is a big model with fan and grill) got alive back in time to cook a roast :) The old chap is still with us even today.
In the process i also had to diagnose it's replacement with was still boxed NOS for 14 years, turn out the connection between the HV diode and the chassis was poor (oxide layer maybe?), after rescrewing the diode the thing started to work correctly. Super nice video anyway and looking for information when dealing with HV is always a must.
I used to fix microwaves 15-20 years ago as part of being a trainee electronics tech. It's not worth replacing the magnetron (wasn't back then either). What we used to do with faulty/bin jobs is take the switches out, and also dismantle the magnetron. The magnet in there is brilliant to mount to a work bench to magnetize screw drivers etc. Just dont put it under your bench and lean on it with a wallet in your pocket.... good bye credit cards. 🤣
nice fault finding vince ,for checking HV diodes i use an old AVO 8 multimeter on the high ohms range it has a 15 volt battery so no need for a pp3..you could go to tesco and buy an 800 watt micro wave for £39 and use the magnatron out of that.
any way what can you salvage first two very powerfull large ring magnets from the front of the magnatron.
second if you cut the high voltage wire off the transformer youcould make your self a spot welder.
third you have a nice low speed motor from the turn table. 3 nic micro switches and a handy fan .so not a compleat loss.
Thanks Rob, I have stored it up in the attic for possible future spares :-)
I use an old megger to check hv diodes and scr's
I'd have thought the caps were there for power factor reasons as microwaves have an inductive load
great video and save parts and transformer... those coils are handy for axial flux wind turbines
The forward voltage on regular diodes is around .6V which your meter can easily handle. For high voltage diodes the forward voltage can be 15-16v or more which your meter can't produce Check the diode datasheet to see what the forward voltage is to determine if your meter can test it normally. Also the capacitor most often has an internal resistor in parallel this can be around 10-20 M ohms if you take the capacitor out they usually have a schematic on it showing the arrangement of the resistor if it has one but you should always manually discharge the capacitor. I use a length of brass rod with a high wattage power resistor in series with a lot of heat shrink for insulation.
Vince,i fix stuff like you,mainly for friends and family,if they asked my microwave isn't working,i wouldn't touch it ! get a new one,just some things i would leave alone !
GR8 lockdown video! time to fix my old microwave...
Do all shopping sites in Europe say "Add to trolley"? That was the most interesting thing in the video to me Vince, also glad you didn't shock yourself.
Well yes cause that way you can continue shopping for more... what's it like where you live?
hi you should keep the transformer it can be useful eg diy spot welder or high current charger
I can't wait to see another trying to fix around the home video's 😊👌👍😎
Just repaired My Microwave HV Capacitor shorted from terminal to Can. Tested the HV diode by connecting 9v battery in series and using diode func on multimeter. Also replaced HV fuse.
nice video.. my first thought that there is faulty fuse.. but sadly there is mangetron fail too.. there may be cheap fix on that mangetron if its only magnetron filament pins is faulty..
th-cam.com/video/U7oyLb_42Os/w-d-xo.html
Thanks for the link :-)
Another really good video Vince, keep them comming. (P.S. I knew you were a "Transformers" fan...20.59 reference to "Megatron"...:) )
I'm also just an amateur, but if the microwave doesn't heat the food, but otherwise everything else works, 95% is caused by a magnetron that produces microwave waves and they force the water molecules in the food to oscillate. They heat up. Otherwise, you went to the problem as always properly from the power supply to the components. Good video.
Vince a magnetron acts like an electron beam whistle. The magnetron causes the electrons to vibrate at the resonate frequency of water. Which heats up anything with water in it. Microwaves have very high voltages and currents.
So close then you had to spread the resonant frequency myth. Consumer microwave ovens are 2.4 ghz, industrial ones vary in frequency. Nothing special about the frequency. Higher or lower would work about the same, with tradeoffs between penetration and absorption. The first microwave oven ever made for demonstrations was 60 MHz even, if that gives an idea what a large range of frequencies could be used. Commercial ones use 915 Mhz.
Fuse is like it has a srping to ensure the separation. Being high voltage I wouldnt try to bodge it with a glass fuse, it can still arc and conduct even when open. If they went into the expense of putting a 6.99 fuse, this is what is expected to replace with.
Thanks bytefree. Very true :-)
The fuse looks like a 0.5£ if ordered by a factory.. Free shipping for one part makes it 6.99£ of course.
Called fast blow personally I dont trust glass fuses I always prefer to use ceramics, when choosing a fuse you need to check current, voltage and speed as there are 4 different fuse speeds slow, normal, fast and semiconductor.
@@rkan2 Whne you purchase at 50K 100K and over price breaks, you get another kind of deal. Of course, Panasonic is not paying this fuse 6.99, moreover, Panasonic manufacture most of their own components at different factories.
Simple way to find what side the fault is on is to probe the HVTX input wires on 230v AC (In Europe), if they are hot then the fault is on the secondary side. Glass fuses are used extensively in microwave HV circuits, but are much longer, this is to create a good airgap that the high voltage cannot bridge when the fuse blows, (they also have a spring which absorbs shock and pulls the filament cleanly away when it ruptures).
Really microwave ovens are only radio transmitters, they focus radio waves created in the magnetron down the feedhorn into the oven causing the water molecules to vibrate and generate friction. The problem is they need dangerously high voltages to achieve this, my understanding is that the step up transformer elevates the 230v to around 2500v then the capacitor doubles that to around 5kv which is then sent to the magnetron to create the radio wave.
So a top tip for the folks at home is to regularly clean dust buildup off the small holes on the back of the oven as this prevents cool air being drawn in and over the magnetron which cools it in operation!!
And if you want to have a microwave repaired drop it off at a service center to have it repaired by a trained professional or the recycling center if you choose to decommission it.
NEVER open them, it could be the last thing you ever do!!!!!!!!!!!
👍
The short discovered in the magnetron
Can explain the short in the blue and yellow wire connected to the switch
The fact that its a digital microwave with no turn dials. And has a turn table makes it worth it to try to fix. in My opinion.
Dial Microwaves are annoying and usually low watt
First time I ever made microwave popcorn, I set the microwave for 5 minutes and then went to the store across the street. Saying the house was full of smoke when I got back would be an understatement.
Nice diagnostics. I have Sharp microwave from 2001, never had any problems with it and it's still working. Looking at this video though, probably good idea to prepare myself buying a new one any day now :-P
not sure about that vintage, but certainly at one point Sharp made the best microwaves. They were pretty hopeless at other stuff like TV's, but their microwaves were well built and reliable.
When you said it wasn't heating, i automatically thought magnetron fault or a stuck thermal cut-out. I was correct about it being a magnetron fault. however after watching this video there a few things that confused me a very small amount. First: since the microwave you had was a processor\digital based one. Wouldn't it have fault detection on it which would then cause it show an error or fault code and fail to start or cut out if a fault condition is detected or is that something that only higher end microwaves have? Second: if the magnetron or if anything in the microwave was shorted to earth wouldn't that trip the fuse\breaker for the plug sockets or earth protection (i'm not sure what's actually called) in the fuse box?
Anyway, I enjoyed watching the video and it was interesting watching you finding the fault while battling the fear potentially getting a major shock off it. I know I haven't commented on your videos in the past (mainly because i have nothing to say) but i do watch them and i do like the content that you provide, Keep up the good work. =)
tear it down for parts, can use the switches, motors and fan for projects.
Just think how many people from the UK or the US would love to have a job in a factory assembling these appliances. Not anymore, most, if not all of them are made in China. Sad really those were probably great paying jobs once upon a time.
I think anyone watching this should really be aware that in the wrong hands, a microwave can become deadly causing great injury and death unless you really know what you are doing. When microwaves first came out, I remember a news article on these kitchen industrial units in a French was it hotel, that operated with the door open and one poor worker walking down this aisle of them all open was cooked from the waist up as these were very powerful ones designed to cook food in seconds. Regardless of whether that is true or not as there were some horror stories of old ladies drying their poodles in 'em, that magnetron will cook a human quite easily if unshielded and it requires a LOT of power to make it happen!
The high voltage section is much more lethal than any radiation you might receive. We had to attend a course before the manufacturer would let us repair their microwaves under warranty. I've heard off other engineers who lost colleagues that accidentally touched the live high voltage section.
French thing sounds like urban legend
That was the most anxiety inducing video I have watched... glad you were safe but would seriously consider more precautions next time with such high voltages :-o
Usually when anything stops on a microwave, it is always cheaper to replace the microwave. Not worth changing parts because they are now so cheap. However, if you are a tinkerer, there are some great parts you can remove form an old one. The transformer usually is still okay, and you can easily remove the secondary windings and make whatever you wish rewinding that secondary to suit your project needs. The make great spot welders for sure... JMHO
Fuse, door switches, capacitor and the diode on the capacitor are the parts that are most common to fail.
Chef Mike: I’m broken beep
Gordon Ramsay: good f**k off
MMV: “Trying to fix Panasonic...”
Me: “How original...”
MMV: “...microwave”
Me: “Daring today, are we?”
At least you have learned about the hi resistor test and also about how microwaves work.👍
The top and bottom switches for the door are "NO" switches. The middle switch "monitor switch" is a safety switch (NC). It will blow the " input power" fuse if it fails and remains CLOSED when the door is closed. So the top and bottom switches should be Closed and the middle switch better be Open when you Close the door to Cook.
The clacking of the microwave door is so satisfying xD
That switch surely works as an interupt. Or at least in my thinking because if you our the door release in so far while the microwave is running it kills the cycle it was doing . Would it interupt voltage somehow rather than the complete circuit ? I'm curious
Hey Dave, after reading some comments I think it might be tied into another switch so both have to open (or close) at the same time. Here it is copied and pasted from Tech Gorilla 'All of the interlock switches must engage at the proper time in the proper sequence'.
@22:58 - FWIW (and I would NEVER rely on them) these capacitors have internal bleed resistors. Within a couple of seconds after powering down, they should be flat or low enough to test with your meter. If you're testing the diode, they generally have a much higher forward voltage than a normal diode, do you must use a higher voltage in series with the diode to test it.
Cheers Tech for the useful tips :-)
@@Mymatevince I often comment while watching and edit when you cover a subject. This one I will leave here just in case. That diode thing bit me once.
It's the big fuse you can see. It always is. They blow if you put anything metallic in the oven and switch on, even stuff with metallic oxide, usually red, paint. Get the fuses for a couple of quid on eBay.
2 minutes in and I know what happened. Someone stuck a bag of popcorn in there. Microwave said. No I'm not eating another bag of that filth.
Just a point about high voltage fuses. The coil that connects the fuse is actually a spring. When the fuse blows the gap between the contacts is increased by the spring contracting. Any other type of fuse may be unable to break the circuit as an arc could be struck across the wire ends inside the fuse body. This, as you may realize, could be dangerous leaving high voltage on parts that shouldn't be: such as the circuit it's connected to, possibly damaging something else connected on that circuit or even shocking someone if the main circuit breaker doesn't trip.
Basically never try to repair high voltage fuses, it's not worth the risk.
One tip for working on high voltages is only to use one hand and keep the other in a back pocket. This ensures that if you are shocked the current flows down past your heart and not through it, giving a greater chance of survival although you can still suffer burns etc. HTH
Nice video though 😊
I was wondering if the resistor that you used to discharge the capacitor were hot or not. after 23:20
Again a very nice video to see how you think when you follow the cable. I'm learning thing Thx :D
Sorry I don't think I touched them to check :-)
@ 37.17 - it (the microwave) has been on fire a couple of times 😂😂geez what are you cooking Vince!!
I had a similar issue with popcorn like that a while back couple years back anyways. :-) what happened was the popcorn that I had was rated for a 700w avg. Microwave. My microwave at the time was 1100 w. and I said it for the time according to the bag and not even within 2 minutes the house was full of smoke and the microwave was all brown inside from the smoke stains. I did not have any problems with a microwave as I still used it for a few years after that. I just replaced it not too long ago because enamel coating inside was wearing away and was starting to rust all over the inside. :-( of course I don't like this new one as much as I like the old one because this new one is much more louder!! :-)
We have the same problem with popcorn, the bag catches on the side of the microwave and it caused one of our microwaves to start arching. We had to buy a new microwave and discard the damaged one. We now put the popcorn bags inside a pyrex bowl and that stops the bag catching on the sides of the microwave (hope this makes sense)
It does make sense, good idea :-)
The diode has a bias of 3 volts, you meter is built for .7 volt diodes. We used a megger to test them, but you can make a circuit with a 9 volt battery.
You should make a jacobs ladder out of the transformer and old coat hangers! ;) High current items in there. BEWARE.
A common problems with microwaes are the fuse on the high voltage side (not 220V but 2500V side) or shorted capacitors inside magnetron between 220V terminals and its case. There are two switches for protection in microwaves - one going open to cut power to big cap and high voltage transformer while the second short its power terminals to ensure discharging of the big cap, if one of the switches failed it blow one of the two fuses inside microwawe (2500V or 250V fuse). The 2500V fuse is typicaly mounted in a pin locked long white plastic case (yours was black). Most of the microwaves have wireing diagrams sticked on the inside of the top shell. The diode (its a HV zener) is 3kV one, you can't measure it with output of 1.5V from multymeter. Yep, the caps inside magnetron's connector are shorted (the magnetron is OK - only the caps inside), you can change the fuse and remove them and/or change the magnetron. The glass fuse in a plastic case is even beter insulation.
Megatron is from Transformers (the movie not the devices) :D a Magnetron does not come from the movie and it is the name of the device :DD
as soon as vince said "been through TWO fires" I had an 'oh shit' moment, perhaps I was subbed to the wrong channel :D
Today we are going to be trying to repair one of the most dangerous and deadly appliances in the modern home... Lol... Vince, you don't want to mishandle that transformer... Please be careful...
We in belgium we call a microwave a magnetron. a magmetron is the metal box that shoots radiation to heat up your popcorn
Same here in the Netherlands.
@@kruleworld hahah😂😂
Yeah. New microwave time. Good job.
at 13:00 thats a short switch, it puts a short across the primary of the transformer when the door is open, the DC resistance of the primary will appear to be a short to your meter.
Measure the voltage to the primary on the trans, if you have mains while cooking go fwd and repair the cooking circuit, (Transformer, HV capacitor, HV diode, Magnetron) if not go backwards and repair the board or door switches, whatever is stopping power to the transformer. Also so you know, most modern MW capacitors have a bleed down resistor built in or on, but never trust them, short them after a min or so disconnected, no power should be left.