Sudden noisy OCZ PSU

dokko · 8 Feb 2011 at 17:26

Hi there,

My computer started making a lot more noise almost instantly, no gradual gain, so opened it up and 99% sure its the PSU fan. There's no smell of burning or anything and performance is unaffected, could this just be a case of the fan needs oiling?

If so what should i do to prep and expect for something like this? (never opened a PSU before)

Cheers.

Steven.

kmufc77 · 8 Feb 2011 at 17:40

Be really careful,im sure in some cases PSUs can still be live even when they have no power connected.

Im sure someone else will confirm this or call me stupid

If your sure its the fan you could replace it with a nice quiet new 120mm

anuraj · 8 Feb 2011 at 17:43

kmufc77 said:
Be really careful,im sure in some cases PSUs can still be live even when they have no power connected.

Im sure someone else will confirm this or call me stupid

If your sure its the fan you could replace it with a nice quiet new 120mm

i think your right.

dokko · 8 Feb 2011 at 17:49

Yeah I read that, i'll do it tomorrow, after my computer has sat unplugged for 8ish hours, but thanks for the heads up. No even sure what kind of fan is in there, got two decent 120mm fans attached to my case, if one of them fits i'll stick it in, can't see the front fans doing too much difference anyway.

mikkyh · 8 Feb 2011 at 17:50

kmufc77 said:
Be really careful,im sure in some cases PSUs can still be live even when they have no power connected.

Im sure someone else will confirm this or call me stupid

If your sure its the fan you could replace it with a nice quiet new 120mm

Yeep, capacitors keep their charge for a while - same with in CRT monitors.

Monkeynut · 8 Feb 2011 at 17:52

Which OCZ PSU is it?

dokko · 8 Feb 2011 at 17:56

Its a 600SXS - StealthXStream

http://www.overclockers.co.uk/showproduct.php?prodid=CA-023-OC

I've had it around 3 years i think, hard to remember!

Baldbloke · 8 Feb 2011 at 17:59

mikkyh said:
Yeep, capacitors keep their charge for a while - same with in CRT monitors.

+1.

They can keep thier charge for a long time depending on circuitry. And, get this, the voltage they store can often be in excess of the mains voltage. (Don't ask. It's something to do with switch mode stuff. Too boring to go in to) But anyway, it's usually current limited. It may not kill but it sure is a rotten way to learn by finding out the hard way. (I have the scars to prove it

)

PS: It could kill if it's still plugged in. Just thought I'd add that bit for good measure.

dokko · 8 Feb 2011 at 18:01

Baldbloke said:
+1.

They can keep thier charge for a long time depending on circuitry. And, get this, the voltage they store can often be in excess of the mains voltage. (Don't ask. It's something to do with switch mode stuff. Too boring to go in to) But anyway, it's usually current limited. It may not kill but it sure is a rotten way to learn by finding out the hard way. (I have the scars to prove it)

Bloody hell! Any way to get the build up out of the PSU?

Baldbloke · 8 Feb 2011 at 18:11

dokko said:
Bloody hell! Any way to get the build up out of the PSU?

Yep. Short the pins of the big capacitors with a selected value resistor for a suitable period of time. (sorry to sound a little vague with that) Not with a wire link. That would make a bang.

Sorry, dokko, didn't mean to scaremonger there. It ain't as bad as I made it sound. Most times it's safe to work on after the timescale you suggested. Often sooner. But no gaurantee. It really does depend on the circuitry. I'm not too familiar with the workings of modern switch mode power supplies. Maybe someone with more recent knowledge can chime in.

Baldbloke · 8 Feb 2011 at 18:47

Baldbloke said:
Maybe someone with more recent knowledge can chime in.

Do we have any up to date component level electronics engineers in the house? I'd love to know if smpsu circuitry has changed much since I was a lad reaching blindly in to the back of a thorn tx100.

mattjd · 8 Feb 2011 at 18:56

In my systems class we got this really big capacitor (about the size of a coke can). Charged it with the mains with a transformer box thing.

The teacher just got a screw driver and placed it on the top fo the capacitor and loads of sparks everywhere... :L

Then he tried pressuring someone into licking it HAHA!

Basically if you want to get rid of the charge quickly then sue a piece of metal with a plastic/rubber handle. Though I would not recommend this because the sparks could damage the other components.

Baldbloke · 8 Feb 2011 at 19:05

mattjd said:
In my systems class we got this really big capacitor (about the size of a coke can). Charged it with the mains with a transformer box thing.

The teacher just got a screw driver and placed it on the top fo the capacitor and loads of sparks everywhere... :L

Then he tried pressuring someone into licking it HAHA!

Basically if you want to get rid of the charge quickly then sue a piece of metal with a plastic/rubber handle. Though I would not recommend this because the sparks could damage the other components.

The teacher was demonstrating exactly why you should not do this. You would damage the capacitor at the very least.

You any further forward with your psu investigation, dokko, or have we scared you half to death?

Lemin · 8 Feb 2011 at 19:06

Opened a couple of noisey old psu's. & the dust was terrible. Both silent after cleaning.

Gashman · 8 Feb 2011 at 19:20

yes for the love of god, don't tamper with your PSU until a fair bit after its been turned off, can tell you from bitter experience that it hurts massively to shock yourself with them, had a tingley arm for a couple of hours after a PSU related incident!

Doggie2k · 8 Feb 2011 at 20:17

I got a OCZ GameXStream 850W PSU and its the most noisey component underload in my system

Its the cheap plastic fan thats causing the noise I'm considering opening it up (voiding the warranty) and replacing the fan. Or just replacing it for something else

My worst purchase by far

dokko · 9 Feb 2011 at 01:35

Lol, nearly scared off but not quite. Needs doing, main PC powered down, unplugged and will get its PSU tampered with sometime tomorrow afternoon, give it well over 15 hours without power. Cheers for the info people, feel a little bit more confident in doing this and not totally frightened off

gumpy321 · 9 Feb 2011 at 06:45

The way to discharge a cap like that is to get a 100w light bulb, solder a pair of multimeter probes to the negative and positive of the bulb and then dischrage the cap.

SouthEastBlue · 9 Feb 2011 at 07:45

Unplug the PC with the PSU still attached, and press the power button. The PC lights should all come on for like half a second, then go off again draining the PSU of its left over charge. Just do that, and leave it for a few hours you should be fine... At least that was the info I was given, and I never got shocked when messing about with my old 500w OCZ StealthXtreme.