How To Repair a Computer Power Supply (or other switching power supply)

UPDATE: The big double Schottky diode has 2 anodes and 1 cathode. Sorry, I accidentally told it the wrong way around :).
In this video I show how to repair an ATX computer power supply and what are the most common failures. Most of these tips can apply to any switch mode power supply (SMPS).
Watch my previous video - How Does a Computer Power Supply Work:
• How Does a Computer Po...
Schematics of AT and ATX computer power supplies:
danyk.cz/s_atx_...
My ATX power supply tester:
danyk.cz/atx_t_...
You can support me on Patreon:
/ diodegonewild
My Instagram:
/ savage_danyk
WARNING:
-This video is not intended for laymen.
-Computer power supplies contain hazardous mains voltage!
-Risk of electric shock and death.
-Risk of fire.
-Leave repairs to professionals.
-You do everything at your own risk and responsibility.

[@RetroLabsNL]

Dear DiodeGoneWild, what you do here is what the internet was invented for: Spreading knowledge of the few to the many. Thank you ever so much for this thorough and clear instruction. I'm going to try and put it in practice right now ;-)

[@BrassicGamer]

Very good. Actually gets down to the component level rather than so many other videos that talk about the fan / paperclip test. And it's actually so simple to test any PSU when you understand the readings that components should produce on a multimeter. Thanks!

In this world where consumption is increasing, your contrubition is priceless.

[@golfman9290]

Your skills knowledge and way of teaching are very much admired and appreciated. Great stuff!

[@ChadDidNothingWrong]

He's so fun and easy to listen to also lol! (He sounds like those chameleon brothers on Rocko's Modern Life)

[@dinukaravi968]

hey ,if anyone else wants to discover pc repairing try Saankramer Electronic Magazine System ( search on google ) ? Ive heard some extraordinary things about it and my neighbor got excellent results with it.

[@Aneesh.Asokan]

@@dinukaravi968 You VERMIN get lost! There are ample videos on KZbin to learn electronics than your shity magazine!😀

[@DrZipZwan]

everyone can learn, but not everyone can teach.

[@steffenstengardvilladsen3740]

I really like how you work with old school/cheap tools and manage to do the job just as good.

[@eduardcojo1749]

I know I'm late but you explained what you had to explain batter than any of my school teachers. :)))

[@nunopereira526]

Best English accent evah!!! My dell psu died and now i'm stucked, i wish i find someone here in Portugal that can fix this like you.

[@AvixkThePig]

Whoa! That power supply tester blew my mind! Definitely going to make one now.

[@josealfredobh]

Very good video. Congratulations DiodeGoneWild. This was the best video about ATX PU I have ever watched.

[@lakecityransom]

13:30 "No explosion yet" 😅 The anxiety of plugging something in after doing electric work...

[@XD2021]

Nah, i will not do this shiit no more 😆

[@hamidmazuji]

you make it look so easy but i've learned that a lot of things that look easy aren't actually easy when you try to do them yourself

[@combatwombat1334]

Practice makes perfect, verily patience is a virtue my son.

[@PescaitoFrito]

Electronic is like playing piano or becoming Grand Master in chess, it does take time, the practice is the key.

[@mr.fixcamer]

I love you Sir. This video is so rich. May KZbin discover your skills

[@xDR1TeK]

This is a good video. For many reasons. I find it difficult to prepare props for a presentation, let alone trying to fix something. I just can't imagine the amount of work that went into this. Good work.

[@umedavk2011]

An excellent teaching video. You are obviously a man of great experience AND patience !! Many thanks :)

[@DOLRED]

I spent a day working on my PC and made a change to BIOS which caused the PC to shutdown and now the PSU appears dead. The first minute of your video revealed what I suspected: There are Mini fuses inside the PSU case. Thanks--going to check it. !!!

[@haseenmultimedia3103]

i really love your simplicity and explanations of failurs. love it.

[@zeewin]

You taught me a lot. You are my mentor and a true enthusiast! Thank you.

[@srs_lol]

His Czech accent almost sounds Indian 😂🤣😂 haha :)

[@pureindiansays6824]

Amma,,,,,just like SOUTH INDIA ,,,,,

[@craig855s]

@@pureindiansays6824 Wait what he's not indian??

[@CharlitoCZ]

I guess hes czech too :-)

[@dipankarroy9752]

South Indian toung and Czech Republic body

[@robertomorales8751]

@@craig855s bro. I'm as surprised as you are...

[@attilarivera]

i like the *_power supply tester!!!!_*

[@manickn6819]

You learn to out a limiter like that when things blow up. I use car bulbs too to test. Quite surprised he did that but its really a good method.

[@hafo821]

i should make one too

[@tmpEngine]

i like the test socket even more, actually I really need that !

[@vesnastankovic7542]

Not certain about the points made but ,if anyone else wants to learn about electronics repair technician try Saankramer Electronic Magazine System (do a search on google ) ? Ive heard some pretty good things about it and my m8 got excellent results with it.

[@georgiosantonopoulos7893]

hi everyone ,if anyone else wants to uncover electronics repair guide try Saankramer Electronic Magazine System ( search on google ) ? Ive heard some decent things about it and my partner got great success with it.

[@Mylity66]

Fantastic video! I've found that 90% of the time its the output capacitors that go kaput on just about any kind of power supply. I have never seen one of the big 400v capacitors fail (i saw one burned because water fell on it and shorted, but it still worked!) Also, usually when capacitors fail they will start inflating, getting deformed tops or bottoms, squirting their electrolyte out or even, in some cases, explode. But not always, sometimes they look like new while being defective that is why having an ESR meter is very important, i really wanted to see yours, its a shame you didn't had it at hand :( Thank you for the video, i've never had a damaged driver circuit on a PSU but now i know how to troubleshoot it. The ATX PSU tester is really cool, i'll be looking it up in your site to build it. I already built your Li-ion battery charger and its being serving me wonderfully :) i had to use a 2k variable resistor, because i could not find a 1k anywhere in my scrap pile so its quite difficult to calibrate XD and also added an LED+resistor to know its getting powered. The only brand new thing i used on it was the solder, even the PBC i reused from an old board after removing all the components and grinding away the traces from it using a grinding wheel getting a plain fiberglass sheet XD.

[@Freakopac]

accents aside, this was so informative, thank you for this great video..keep it up

[@berniemac1124]

5/5. i was able to check my Chinese made PSU and i won! thank you Sir

[@WaltersGuides]

I like when when he says "testeêer" very good explanation

[@CryptoBlockchainTechnologies]

You sir are a genius you earned my subscription!

[@MRPricks]

excellent video fixed my first power supply after watching this you are good.

[@damjanforjanic]

All the equipment is handmade bravo.

[@semiRockethr]

I actually repaired my first PSU by finding similar or same schematic on your website. Thank you for that database. That was way before you started making videos in English. I wish I had this before :D

[@ΕΥΣΤΑΘΙΟΣΦΙΛΙΠΠΟΠΟΥΛΟΣ]

MY NAME IS STATHIS AND I AM FROM CREECE YOU ARE SO GOOD ABOUT ELECTRONICS !!!!

[@drawfark]

I think this is my most favorite KZbin video ever!

[@PescaitoFrito]

This dude is the god of electronics.

[@andyb7339]

Very good and easy to understand 👍

[@DolezalPetr]

ten power supply tester je naprosto parádní, fakt dobrej nápad (y)

[@realfamvigilante2829]

Hey man you are AWESOME! & I love your videos! The only thing that bugged me was how LITTLE flux you used lol, I'm the kind of person that drowns it in flux lol, but for real though you got some good content keep it up!

[@martinleska4292]

If the 22ohm resistor is burned or overheated, I recommend change 47u/50V capacitor near this resistor. I have few ATX where this capacitor has less than half of declared capacity and high internal resistance.

[@ilijafilipovic4625]

Martin Leška

[@mihaelkubatka1410]

I must be honest and say that your acent in really weard but it is amazing how do you manage problems and explain logic of complex electric circuits. Well done and looking forward to new videos.

[@dragan3290]

Beautiful job! You sir are an excellent teacher!!! Subbed and liked and cheers from Australia 👍

[@mrmcquade7890]

Wealth of knowledge - Thank you so much for sharing - GOLD!!!!

[@artkaboom]

I knew nothing about the PS, and now I know something. Use a professional! many thanks.

[@Ridata01]

very good video my friend, one of the best in youtube that explains everything

[@German_byte]

I really appreciated the video. I learnt various things from it.

[@breannestahlman5953]

So sad that I'm not at the level to get full benefit, but I watched it all anyway, thank you.

[@Lwhchris]

Great video. Should be shown in any power electronics class or power electronics related projects. Wished I've come accross this video when I was doing a project about switching power supplies.

[@dagmite]

This is super super excellent Bravo.!! Hey man you are the best! 🤗

[@alexy.9306]

Thanks for leaving a warning in the beggining of the video

[@DineshKumar-ty6fq]

Best video on power supply repair

[@saarike]

Thank you very much for this complex failure fix and precious information!

[@MIXT55]

Putting this video in my favorites!

[@octavmandru9219]

Bravo, mr. Respect your skills. Thanks to your videos I started troubleshooting a very nice PS and learned a lot in the process

[@makedaevilmage]

Thanks for the video! It's been really informative. I have two broken psu's that I want to try to fix. At first sight they both have faulty capacitors that I want to replace, then see if they work using a simple psu tester.

[@johnmathias9892]

I would make sure you discharge those 400v capacitors first. Use a 10W 100 OHM resistor with insulated leads on both ends to avoid shock

[@peddersoldchap]

This should be pinned

[@stensmann]

Yeah! I would like to see some schematic from it! And i saw the first cooled current limiting bulbs! an another hand, i liked very much the way that you, step by step, show us the things... Congrats!

[@sirkllr]

I'm glad I stumbled across your KZbin page

[@RaindropServicesNYC]

I live that light bulb tester you made. What a great idea. I'll definitely borrow the idea from you. Thanks...

[@1pcfred]

It is not so much a tester as it is an over current protection circuit. When you draw too much current you just light up the bulbs. Bulbs are natural PTCs.

[@joellinazapacadar]

i learned a lot in your tutorial sir about trouble shooting

[@FantaBH]

Well done my friend, good school for those who do not know how to do it.

[@ovalwingnut]

Fantastic. Classic Flash Back DGW. Seriously love the PSU tester and that turnee cool piwer switch. Just missing the cat. Cheers 💙

[@Cagmito125sportsbikespares]

This video got better and better , thanks a lot .

[@SilverMoonJoe]

Thanks for sharing.. each technician has it's own way to do things..yours are unique to you and very impressive. Thanks, Joe-K4JGA - JGA Electronic Repair Center - Florida-USA

[@Okie-00-Spool]

This is a really good instruction video. I really appreciate your way of explaining things.

[@_Reviewer]

How do you post $2 blue label in comments?

[@MagsWorksandHobbies]

Love that power supply tester using array of leds.

[@davidbrewer7937]

You miss the most important thing at the start of the video: DISCHARGE TWO BIG LINK CAPACITORS BEFORE NOT AFTER YOU GET A HUGE SHOCK OR BLOW UP YOUR METER.

[@conkerconk3]

they have discharge resistors connected to them, so you dont need to. and those resistors will most likely never fail

[@davidbrewer7937]

@@conkerconk3 1> You cannot rely on the design having the resistors. 2> These are called balancing resistors to make sure that the voltage applied to a pair of link capacitors arranged in parallel. They work like a voltage divider & they can fail because they have a high voltage across them in normal use. Better not to assume...

[@davidbrewer7937]

@@LonesomeToast Hey...I am 38 years in the business & still alive but once took 30kv for 2 seconds in a factory test system & survived!

[@royokimoto5150]

@@davidbrewer7937 organ damaged bud?

[@davidbrewer7937]

@@royokimoto5150 No I was very lucky. It was a gantry over the top of a production line making CRTs in LG Wales. I foolishly reached down to reattach the final anode hook to a CRT which was passing under on a conveyor without thinking but the gantry was right over a B-stray test system & it turned on just at that moment. The CEO of the firm I worked for was visiting & I was showing him the problem we were having with this third party supplied equipment & the anode hooks which kept falling off, which exposed our test systems down line to destructive bad product. He said that there was a six inch lightening bolt that came out of my ankle to the guard rail. My dying words would have been "fucking bastards!"

[@beogeek]

I love the test socket you've made, be great if you showed a video how you built it!

[@peksn]

wow this has so much information clearly explained, everything you need to know is here thank you! :)

[@LouisEmery]

You must be very popular, fixing everybody's power supply.

[@GoutamDAS-ls1wb]

This is a great video on how to troubleshoot and repair a defective power supply. However it seems like a good 2-3 h investment. It seems that there is no easy way to identify the defective component(s) and replace them. And so we would be looking at an approximately $50 savings at most! But very, very educational! Thanks very much Sir!

[@_rose_Hyperthread]

Very informative and educational. You showed me a lot. Thank you so much! And your accent is SO AWESOME!! 🤟🔥🔥

[@northstarstatepolitics1652]

Your accent grants an automatic like

[@johndavid8303]

You have a very good skills in electronics...Big Up!

[@goodideas5659]

Great video ! - I just successfully fixed a broken 850W Gold lable PSU with 1 faulty electrolytic - yippee !

[@roneycorrea]

you are doing a great job! please continue!!

[@MiguelDelArco1963]

No hablo ingles, pero es que nada de nada. Así que le pongo los subtítulos, escrito entiendo algo más. Los vídeos de diodo me parecen interesantes y es de agradecer que no haya música. Afortunadamente para mi los subtítulos funcionan muy bien en los vídeos de diodo. Así que todo el asunto del acento no me distraen de lo importante y es que las explicaciones a nivel visual son claras y concisas. I do not speak English, but it's nothing at all. So I put the subtitles, written understand something else. The diode videos seem interesting to me and it is appreciated that there is no music. Fortunately for me the subtitles work very well in the diode videos. So the whole accent issue does not distract me from what is important and is that the explanations at the visual level are clear and concise

[@nakomarumpus]

This bring one meaning... Buying new one will be more worthy for our time and money.

[@smartliving8062]

👍👌🙏 Very nice clip with very simple explanation, you must discharge two big capacitors in the beginning, also we wanted to know how you test capacitors by using your ESR Capacitor tester. Short circuit between green & any black wire & fan start running is also very good. Thanks for creating this useful video showing stepwise procedure & do it for other topics in future.

[@BenjaminEsposti]

P.S. The two input filter capacitors rarely fail. When they do fail, there are two common causes: 1. The input voltage switch was set to 115V but the PSU was plugged into a 230V socket. 2. One of the balancing resistors (typically around 150k ohms each) has gone open circuit.

[@plamenpetkov6958]

The input caps operate on low frequency (50/60Hz) i.e. experience peak currents at low rate. The output capacitors operate at over 100 kHz i.e. tend to wear faster, especially in conditions of elevated tenperature

[@v8consumption]

Wow this video just helped me alot by ordering a new power supply

[@mohammedmariff9034]

good creative real engineer .. allways watching and trying to learn reverse engineering frim you ... good luck

[@oumarabagaro1523]

v.good presentation Thanks so much 👍👍👍

[@kanlungan07]

So im back with my computer power supplaaaaay In the last video I was explaining how does it woooork But anyways you’re teaching is excellent.

[@asifaslam2649]

You are a good teacher

[@dimuthumadusanka6994]

Super explanation. Tank you. I learned lot of things from you. Thank you again. Good luck.

[@orveahava]

Thank you so much. This is one of the most informative videos i have come across❤

[@wasanthawimaladharm]

Extremely appreciated for complete guide,well done !!!!

[@boonedockjourneyman7979]

One of your best videos.

[@hiimaxel]

More videos like this please,very helpful!

[@bxkid7]

Excellent video wish other did explain like you. TY.

[@CaptOverShoot]

Great Video, I have learnt a great deal about PSU units, I have a PSU that shuts down and restarts, this occurs normally twice in a few minutes, then it runs fine for 2 or 3 days sometimes for a week and the same occurs again, I think it will be a very difficult fault to find. Shame as it is a semi-modular CX750M and it has been replaced now........ as it was driving me mad.

[@antraciet]

Difficult repair but you found it. And yes, that is how i learn too, and is fun to repair something that was difficult.

[@BryanChance]

Great video crash course in power supply trouble shooting. I especially like the detailed explanations with schematics and diagrams. Thank you. Your power tester box and the ATX tester is awesome!! Do you have a video on how to make them?

[@danatmonst3594]

I hope so, I only discovered his channel today!

[@vladsid3453]

thank you for this i have lots of broken psu

[@blackterminal]

Fixing a power supply is a labour of love as you can buy another junked computer and take the power supply out of that. I still like to try to fix things.

[@jakes-hy7zf]

Thank you so much. Im a noob, so i guess buying a new onecwil be better on a short solution. Got a lot of power supplies. Will try in future

[@rikka0_059]

The one you repaired uses the classical tl494+lm393 circuit, newer models often come with apfc and some of them are llc or forward converters, these atxs have more components and are much harder to fix

[@lopkc]

You make really nice videos

[@عمارةحامدي-ذ7غ]

thank you very much that interested me a lot especially when the measurements are taken with the power off

[@CreativeChannel-KST_VN]

I really like what you do. Worthy to follow

[@JoeGP]

you talk funny and kinda annoying, but that was a great video, i have a very good (expensive) PSU that i killed by accidentally shorting the USB socket and now i'm trying to fix it, this video has helped a lot. There was no sound when it died and nothing looks burned, so it's gonna be difficult to find the problem.

[@wilsard]

nice work. thanks for the video. there are few this good on youtube.

[@amicklich6729]

Glad I found your channel! I'm enjoying it and learning :)

[@davidbolha]

A Micklich Hi, He has a 2nd channel - Deirones. He makes free energy devices ! 😁

[@leonguerrero3630]

appreciate your good stuff bro. keep it coming.

[@electronicguy4550]

Wow you are realy good at this