Question about a cap inside a 350W PSU

[Kugaro]

Hey there folks. Just a quick question here, I really don't know alot about electronics but I was able to at least identify the problem. The missus turned on her pc the other day to hear a loud POP followed by a smell similar to if you had lit a match recently. I checked the usual, fuse/plug/wall outlet and went on to remove the power supply from the pc. It smelled pretty interesting, so feeling confident I'd found the culprit I opened the casing up. Sure enough, there was scorching around a small screwed-on pcb and on it was a burnt cap. Beside it is what looks like a damaged resister which I assume was caused by the heat of the capacitor burning.

Now, at this moment in time I'm buggered for cash. And I'll be honest, having her sitting for hours on my gaming rig scouring Facebook is grinding my nerves.

I've taken apart just about every single bit of 'temporarily disposable' electronic equipment I have and CANNOT find the appropriate 2.2uf 400v capacitor to replace it with. The CLOSEST 400v cap I can find is a 22uf 400v cap (see the image below).
The only 2.2uf caps I can find are 1/8th of the voltage, 50v, and I'm fairly sure that'd be a very very bad idea to use. Would it be safe to attempt to replace the burnt 2.2uf cap with a 22uf cap? Or is that EXTREMELY dangerous? I've taken apart a 30w Marshal amp, no good. Only 50v 2.2uf. A 5.1 speaker system, no good. A 2.1 speaker system, no good. The only thing even CLOSE was a power board from a small DVD player, and that's the 22uf 400v cap I'm talking about. Is there any alternative's I can try or am I buggered to suffer hours of Facebook 'til I can get one of these caps?

Many thanks in advance for even reading this!

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[retiredcaps]

Re: Question about a cap inside a 350W PSU

The general rule is to match capacitance exactly. Some say you can go about 20% higher in capacitance. Going from 2.2uF to 22uF would not be recommended.

Since one cap blew, the chances of the other one (next to it) being bad is very high.

If you live in the USA, ordering 2 brand new caps with shipping should cost less than $5 from something like digikey.com.

You may want to test the resistor and other components before powering up.

Beside it is what looks like a damaged resister which I assume was caused by the heat of the capacitor burning.

I've taken apart just about every single bit of 'temporarily disposable' electronic equipment I have and CANNOT find the appropriate 2.2uf 400v capacitor to replace it with. The CLOSEST 400v cap I can find is a 22uf 400v cap (see the image below).

[Kugaro]

Re: Question about a cap inside a 350W PSU

Problem is I live in Ireland, and the local Peats Electronics or Maplin actually don't have staff who can help me with Caps.. which shocked me. So I'd have to mail order from the US or so. Thank you for your reply though it's very much appreciated retiredcaps.

[370forlife]

Re: Question about a cap inside a 350W PSU

http://uk.farnell.com/jsp/search/bro...lues%3D1000224

[yyonline]

Re: Question about a cap inside a 350W PSU

Problem is I live in Ireland, and the local Peats Electronics or Maplin actually don't have staff who can help me with Caps.. which shocked me. So I'd have to mail order from the US or so. Thank you for your reply though it's very much appreciated retiredcaps.

Not even many people here in the US have a local electronics shop which stocks any sufficient variety of capacitors. There are online distributors in the UK who sell capacitors. I figure ordering from the UK would have to be quicker than shipping overseas from USA. I'm not sure what the stores are, but a quick search on here should give some answers. I know there are a few members from the UK as well who can perhaps chime in with some suggestions.

Edit: someone beat me to it!

[Scenic]

Re: Question about a cap inside a 350W PSU

with a wrong search though. the linked search is for 22uF caps.. not 2.2uF.

but no wonder those Teapos failed. they don't like heat. putting them next to some hot running resistors isn't quite that intelligent.. lol

Teapo/Yageo SEK series is 105°C general purpose BTW. (*click*)

[370forlife]

Re: Question about a cap inside a 350W PSU

http://uk.farnell.com/jsp/search/bro...lues%3D1000224

Whoops, need to slow down when I read some of these.

[Scenic]

Re: Question about a cap inside a 350W PSU

hm.. noname PSU.. wouldn't be suprised if the secondary side caps are crap aswell.. :/
at least the heatsinks look kinda beefy enough..
if you can't fix that PSU up and can't find a halfway decent replacement, i could send one out of my pile of PSUs over there. shipping only.

[370forlife]

Re: Question about a cap inside a 350W PSU

It's a sirtec. OK psu, will do it's ratings.

[Scenic]

Re: Question about a cap inside a 350W PSU

mkay.. didn't look up the UL number..
label looked like a generic cheapo..

[momaka]

Re: Question about a cap inside a 350W PSU

Can you post a less zoomed-in image of the PSU, preferably taken from the top? Based on your description and the images, that capacitor might be part of a voltage booster circuit on the primary side. If it turns out to be this, you can safely remove that whole circuit as it's not critical to the function of the PSU (more details on that can be found here: https://www.badcaps.net/forum/showth...1&page=6&pp=20)
But again, I need to see a less zoomed-in image of the PSU to confirm this.

[RJARRRPCGP]

Re: Question about a cap inside a 350W PSU

The images were deleted.