Inside a Failed ATX Computer Power Supply

This is a quick disassembly and overview of a failed power supply that I recently removed from my computer after it failed one day to turn on. I show some of the components, what they are, what they do, and why it failed.

[@MarkHera91]

Great explanation, thanks!

[@knurlgnar24]

Ground is common, although each voltage plane has its own GND conductors to prevent GND offsets. If you share grounds a load transient on one voltage plane will greatly affect the other voltage plane sharing that same ground wire. The ATX spec details are free to download if you want more details than I can give off the top of my head.

[@johnkeating4221]

Great video thanks for sharing

[@Doom2pro]

PFC is only required in Europe, and for voltage doubler/switch selection designs the most you will ever get is 220V capacitors... 400V or higher is for PFC which has a buck boost.

[@ibanez2010]

Cool video. Thanks!

[@allanmck]

Old video I know, but if you don't mind I have a related question. I've been using an AT supply to power a car amp and speakers indoors. Watching some videos online to check my facts on amps I notice comments from some on how all the yellow (12v) leads need to be connected together to provide the full amperage. I've been using only 1 lead but have also had it deliberately limited to half volume to reduce load as I was never sure on the compatibility. Checking my numbers now it's a good thing as the PSU outputs 12v 12A and the amp is 20A haha. But it has worked for years as is so I'm happy. Anyway, your input to the multiple leads question would be appreciated.

[@JoshuasRecordings]

Allan McKenzie One wire is fine (yellow and black). The only reason to put all of them together is if the wires cannot handle all of the amperage, that could overheat the wire.

[@allanmck]

Joshua's Recordings Thanks :)

[@MrMacroVision]

the key is the voltage selection switch, if is has it there is no active pfc, older server grade psus have passive pfc, and the therefore no need for the 450v caps. as the higher voltage removed(in theory) by a diff tap in the transformer

[@WarriorOfMetal]

Is the ground common to all connections, for exemple could be used the (in the molex) 5v ground with the 12v line?

[@Obez45]

11 years! So far I've had one that lasted 4 months and another that lasted 1 month

[@felixcat4346]

Not having active power correction is not necessarily a bad thing. The circuit works like it should. APC is useful if you live in areas with a shitty power authority sending you bad ac to your mains. Most people will not experience this so why pay for it.

[@jonkohn83]

Thank You

[@knurlgnar24]

Interesting stuff. Thanks for the info!

[@MsJinkerson]

I always repair mine I have done 22 power supplies and all worked

[@ryantoomey611]

Best brands are Antec and Corsair. That is all I buy for PC builds. Never let me down yet.

[@torchedegg]

Only Asus and corsair

[@boowonder888]

I have an old defective ps, . Looks like one of the early to mid 90's. It is 65w and the plugs are very old, it doesn't have the big main plug. It doesn't have the green wire that I can bridge with the ground wire. I opened it up and all the caps look good, no bulging. I want to use it for my hobby projects since it rates only a nice and safe 65 w and has an on/off switch, can you help me trouble shoot it?

[@ryantoomey611]

That is the old AT standard used in the early 90's before ATX. There is no green wire to turn it on, you use the power switch instead. If it does not work it is likely bad capacitors due to its age.

[@blackterminal]

I don't think the caps are the main fault. It will be the regulator ic

[@anon2030]

I would’ve kept it bcuz it’s way better quality than the waste they sell today. Just replaced the 2 caps, n it might go another 11 years.

[@maxmustermann19203]

i think my 350 watt power supply is just dead i plug it in brick outlet and i just hear a "boom" it is on 210v and when i just put it again in the brick outlet i just hear again a loud bang inside. its on a 110v on a regulator and a setting on the psu 110v???? or i just need to dump it???

[@buttbuttersonmcbutt795]

Michael Lopez same

[@buttbuttersonmcbutt795]

Michael Lopez try and get it repaired

[@jonathanharris2090]

It served you well yet you won't save it by replacing caps. Very very sad.

[@GimiBsk]

Why save it, just buy new one plus the new technology is way better

[@ryantoomey611]

It probably failed because it did not have a large enough 12 volt rail for modern day PCs since it is from 2001.

[@saturn7_dev]

simple repair - just fix it. Its most likely going to last longer than buying a new one today unless the output just cant cut it...good for backup even still

[@knurlgnar24]

While you're probably right I did not repair this supply. The landfills of the world are full of such treasures.

[@saturn7_dev]

Yes, that's true. The best PSU I ever found was to be thrown out from a PC repair store - I found nothing wrong with it and used it for years until I sold it later on...they thought it was faulty but no, obviously something else. I like repairing stuff, makes me feel good to reuse and repurpose stuff...

[@JoshuasRecordings]

Antec is NOT a cheap brand! Actually they are a really good brand! I would have put a Antec PSU into my build if they were not so expensive!

[@LPmitCG]

be quiet! is the best

[@calculus3661]

***** Antecs have been and still are the top quality brand in PSU's. Seasonic comes right after. Be quiet! has about 5 good PSU's and the rest are shite.

[@NikolaiMTA]

CalculuS If they're apparently so great, why does my VP550P have such a retarded rail arrangement?

[@calculus3661]

NikolaiMTA Pretty much normal, you either have a single strong rail or you have 2/4 slightly weaker rails.

[@JoshuasRecordings]

NikolaiMTA What is wrong with the rail arrangement?

[@adwaitagnome]

yes, you CAN find cheap PSUs today, but I would not recommend it. Get a more expensive model from the likes of Corsair, EVGA, Be Quiet, Seasonic, ect. These companies usually make very-high quality power supplies (for example, mine, a SuperNova 750G3, has a 10 year warrenty, which might indicate how long this PSU is expected to last)

[@SeaJay_Oceans]

This is why people want real Japanese solid capacitors, and some air flow inside the Power Supply, to help protect from overheating...

[@blackterminal]

More wanted you to just talk about the fault