Think I fried my mobo...electrical buzz sound coming from PSU

[StealthyV]

Hello all!

About 2 weeks ago, I decided I was spending too much on electricity and decided to power-down my computer overnight and while I was at work. Normally, I leave my computer on 24/7 running UD (distributed computing). Upon returning home, I was unable to boot the computer.

I heard a "buzz" sound coming from the psu, and upon closer inspection, when I pushed the power switch (after unplugging and checking the cord, then plugging back in) the fan in the psu "twitched" while the psu made an electrical buzzing sound. The fan did not complete a full revolution.

System specs:

AMD Athlon64 3200+ 1.8ghz cpu
480W Thermaltake Silent X Purepower PSU
2x 512mb Crucial ddr-400
2x 120gb Western Digital 7200rpm IDE drives
2x SLI-Express nVidia 6600GT's
A8N-SLI Deluxe mobo
DVD-R/DVD-RW from Liteon

I just installed a brand-new Thermaltake 700w Toughpower psu, thinking it was a bad power supply. I got the same problem. The "buzz," the fan 'twitching' and nothing else working.

The lights on my mobo are glowing, so I know there's power going to it. I have disconnected all power adapters except the ones going to the motherboard, trying to get at least a POST beep, but nothing.

I followed this guide and got down to the part that says: "Try drive in test pc." I have to skip this step tonight, because my spare computer is at my parents' house.

For a few months prior to this happening (and yes, this probably is the cause of the problem), whenever I would shut down the pc, I would get two long "beep - beep" sounds from the mobo, and then I'd have to shut down manually. Is this an indicator of a dead mobo? I have looked in the manual for the mobo but haven't found anything on the beep codes, and online documentation is spotty at best.


Thanks all for reading, and I hope someone can shed light onto my problem! Having just sunk $164 on a new psu only to have it "fail" too...I'd like to figure this out before my RMA period ends!

~Branson

[StealthyV]

^bump... I could really use some help!

[theedisoneffect]

Maybe a dumb question, but have you tried plugging it into a different outlet? Definitely take it off any power strip/UPS/surge protector and try it directly in a wall outlet on another circuit.

[StealthyV]

actually not a dumb question, but yes I have tried plugging it into a known "good" outlet.

I'm ordering a psu tester from newegg...before I RMA a new psu.

any other suggestions are certainly more than welcome!

[RicheemxX]

I'd skip buying a p/s tester just use a multimeter {or buy one instead}

but first off try jumping the p/s without the motherboard and other components follow this guide, no you don't need the switch just use a wire or paperclip.
http://www.gideontech.com/content/articles/196/1

I've never heard of a bad mobo causing your powersupply to buzz but I could somehow be causing an overload issue I guess?

[theedisoneffect]

^
Yep, $10 multimeter will do everything you need, and you might actually use it for something else afterward.

With the multimeter, I'd also recommend testing the original outlet and any power strips and such it was plugged into to begin with. If there's something wrong with the power coming in, it could've killed both powersupplies in the same manner.

But... I'm starting to agree that it's prolly not a PS problem. You said lights on the motherboard were glowing. A green LED would prolly be normal, but were there others?

[DanU]

Quote:

Originally Posted by RicheemxX

I've never heard of a bad mobo causing your powersupply to buzz but I could somehow be causing an overload issue I guess?

I was thinking along these lines as well. There could be a short somewhere and the power supply shuts itself off as a protective measure.

Try removing the motherboard and PSU from the case. Place it on a non conductive surface and power up the computer with just the motherboard, CPU, CPU heatsink, RAM, and video card. Hopefully you will at least be able to power up and POST.

[StealthyV]

Ok, so I used the paperclip method on my old power supply...and it's definately kaput. I plugged it into a different socket, at the other end of my apartment. It's on a different circuit.

I haven't yet had the opportunity to try that method with the new psu, but I'll be getting to that this afternoon.

So you folks are thinking that if the power isn't dirty, it could be a short in the case? It's a Chemning full-tower case...all-steel...no aluminum. haven't had any problems with it since I bought it in 2002, but of course anything's possible.

Any additional suggestions are most welcome!

~Branson
tryin to get into good spirits...even though I don't have internet access at home now

[theedisoneffect]

Well, if there was a short, it would have to be from the motherboard to the case. That's the only place it really could be, unless by some strange happenstance one of your drives went spectacularly toasty. You'd prolly notice that, though. Black marks and such. Maybe try removing the motherboard and making sure there isn't something bridging a ground where it shouldn't.

Wait... I know where I've seen this problem before...

Check and make sure the voltage selector switch on the PSU is set to 120V instead of 240. Both on the old one and the new one.

[extitude]

The processer fan didn't make a whole revolution?
It doesn't take much to move that small of a fan.
I would think twice before using a new psu and thinking all was ok.
Look for swollen capacitors on your mobo.A small bit of swelling does not mean that the capacitor is bad,it could mean that the current travelling to it is perhaps faulty.As well clean your motherboard well so as you can see any hot spots on the circuitry.
Just a thought,good luck.