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geekhack Community => Other Geeky Stuff => Topic started by: sam113101 on Sun, 07 November 2010, 22:39:03

Title: PSU problem.
Post by: sam113101 on Sun, 07 November 2010, 22:39:03
My comp was VERY noisy, so I told myself it was the time to remove the dust. To my surprise, there wasn't much dust on the CPU fan. I blew some canned air into the PSU. Now, the noise is terrible, it's far worse than it was. Why is my PSU acting like that*?
Title: PSU problem.
Post by: 8_INCH_FLOPPY on Sun, 07 November 2010, 23:05:46
Try *unplugging* the psu, removing the cover and vacuuming the inside out.  PSUs fail when too much dust builds up and they overheat.  Your PSU has a fan.  You probably blew dust into it.

I had been getting BSOD crashes intermittently for several months.  Eventually, they got so bad that I pulled the psu out, opened it up, and found a thick layer of dust covering everything.  It's been about three months since I cleaned it out, and I have not experienced a single crash.

I'm not saying that is going to happen to you.  I'm just recommending you take action to prevent it.
Title: PSU problem.
Post by: Rajagra on Sun, 07 November 2010, 23:15:38
Using canned air on a fan can cause it to spin too fast causing damage. Bit like revving a car engine in neutral with no load to balance the forces.

Might be temporary though. If you can remove the fan you can whack it against a table to try and reseat the parts.

Having said that, if it was noisy and relatively dust-free before, it may have been partially seized for some time. Time to replace the fan or PSU.
Title: PSU problem.
Post by: Phaedrus2129 on Sun, 07 November 2010, 23:36:18
What is the brand and model of the power supply in question?
Title: PSU problem.
Post by: Ekaros on Mon, 08 November 2010, 01:18:18
Yeah, got dead PSU and ended up replacing it with a new one and the case at same time. Seems like they are upgrading their desings. This one has own intake for PSU and dust filter for it. PSU is only doing it's own cooling. Unlike my old case where it was only exit went too...

Heat can also kill them, still cleaning the PSU might help, but leave it on table for sometime if you are going to clean the inside just in case...
Title: PSU problem.
Post by: ch_123 on Mon, 08 November 2010, 04:22:39
If you're opening a PSU, be as careful as hell that you don't fry yourself.

I never knew airdusting fans could damage them, it would explain why the fan in my Thinkpad is ****ed though.
Title: PSU problem.
Post by: chimera15 on Mon, 08 November 2010, 04:37:21
If it's making a noise it's most likely the cooling fan, not the psu itself.  Fans wear out their bearings, unless they're bearingless like on most laptops.  You can usually replace them with standard case fans.  I've had a number of constant running systems wear them out.  Usually takes about 5 years of constant running or so.  I've done a few replacements of the fans.  Usually only costs $5-10 at most.  They even sell replacement fans that are sold as case fans that will work on most at Best Buys.
Title: PSU problem.
Post by: zefrer on Mon, 08 November 2010, 05:48:12
Yeah what chimera said. If it was making a noise before then the fan has probably died/about to die. Can be replaced pretty easily, as long as your PSU is not about to go as well.
Title: PSU problem.
Post by: Rajagra on Mon, 08 November 2010, 06:04:34
If you do replace the fan, may as well get a quiet one. Even if it costs a bit more it's likely to be much better quality than the cheaper ones.
Title: PSU problem.
Post by: EverythingIBM on Mon, 08 November 2010, 09:00:47
Quote from: ch_123;244148
If you're opening a PSU, be as careful as hell that you don't fry yourself.

I never knew airdusting fans could damage them, it would explain why the fan in my Thinkpad is ****ed though.


Interesting, I shoot compressed air in my fans all the time; never had a problem with any of them (of course usually they're all turned off, would be kind of silly blowing air into a running fan).
Title: PSU problem.
Post by: Fwiffo on Mon, 08 November 2010, 12:05:16
It may be that the fan in the PSU was already bad and noisy (considering the whole computer was noisy and it didn't seem to be caused by some other fan) and that when you blew out the dust it just made an already broken fan worse. If the fan is broken the whole PSU may be on its way out.
Title: PSU problem.
Post by: keyb_gr on Mon, 08 November 2010, 14:51:27
Might be a good time to check whether the power supply is any good at all. If it's a lightweight cheapie, I'd rather toss it and install a quality new one (80+ certified, yadda yadda). Of course that assumes a reasonably modern computer that's heavy on +12V, not an oldie with CPU power from +5V.

80 mm fans normally last a fairly long time, definitely so if temperature controlled. A PSU that doesn't have a temperature-controlled fan is either very old (>10 years) or cheap trash.

And yes, it's a good idea to remove mains power a few minutes (at least) before opening a PSU. They normally have bleed-off resistors so the high voltages will go down relatively quickly, but still better safe than sorry. DC voltage after the primary-side rectifier can be up to about 385 V, so the filter capacitor can bite quite a bit.
Title: PSU problem.
Post by: Phaedrus2129 on Mon, 08 November 2010, 15:09:09
He hasn't posted again.



I'm the PSU guru. Don't know much about fans, but I can tell you if it's a cheap Chinese piece of horse **** or not.
Title: PSU problem.
Post by: Ekaros on Tue, 09 November 2010, 10:06:54
Quote from: Phaedrus2129;244389
He hasn't posted again.



I'm the PSU guru. Don't know much about fans, but I can tell you if it's a cheap Chinese piece of horse **** or not.

I went overkill and went for 650W Corsair TX, freaking 89€... And running it in 4/6 year old computer. But atleast I now got something which run my next comp for 5-10 years...
Title: PSU problem.
Post by: D-EJ915 on Tue, 09 November 2010, 19:46:27
Don't bother trying to replace the fan, you'll have to solder more than likely.  Get a nicer aftermarket or OEM PSU instead.
Quote from: Ekaros;244615
I went overkill and went for 650W Chieftec TX, freaking 89€... And running it in 4/6 year old computer. But atleast I now got something which run my next comp for 5-10 years...
I've used seasonic OEM ones in my new computers and they have worked great for me so far.  SS-650HT for my quad and SS-860HT for my octo
Title: PSU problem.
Post by: ch_123 on Wed, 10 November 2010, 04:27:06
Some (up to about 650W) Corsair PSUs are just rebranded Seasonics, which is why everyone loves them.