PowerSupply: defective or normal?

[GreenGrinch]

Hi guys,
My power supply is making a faint high pitch noise that's pretty annoying. It's an Enermax 350W FC. I thought it was defective, so I send it back, and I got a new one which doing the same thing. Is this normal or am I overloading the PS? Or I just had bad luck w/ this 2 PS? With this 2nd one, when I just boot my computer, it has no noise, but when it's loading windows, the noise came.

My system consist of: Epox 8RDA+, XP1700+ @ 1.8GHz @200MHz FSB, 512 XMS3200, 120GB HD, 80GB HD, 1 DVD-Rom, 1 CDRW, 4 case fans and ATI 9500Pro.

Joel

 

[Geniere]

A switching power supply runs at a high frequency for efficiency and smaller componant size. Likely you're hearing noise from the transformer. Since both supplies had the same symptom I would guess its a not a PSU problem but a HD problem. My reasoning is that the HD is drawing more current than it should and loading down the PSU. I would measure the voltage to the HD as its booting and note if it drops when the HD kicks in. A fractional change in value would be ok.

Regards

 

[GreenGrinch]

Hi Geniere...

Thanks for your post. How would I measure the voltage of my HD? But you remind me of something else. With the first PS, I was using my old ATI card and I don't have this problem, then after I installed the 9500Pro, I start to have the high pitch noise.
Also on the 2nd PS, I noticed that it makes the high pitch noise when the logon screen about to come up, not when it's loading windows. So could it be that my 9500 Pro is defective? Or maybe 350W is just not enuf juice?

 

[Markfw]

My guess is still the PSU after what you said. The video card doesn't take as much just during boot, and when it goes into Windows, it kicks into high detail. Unplug the monitor to be sure it is not that. (power)

 

[GreenGrinch]

Mark,
How would unplugging the monitor eliminate the vid card as the culprit?

 

[GreenGrinch]

Another thought... I'm using PowerColor Radeon 9500 Pro, but using ATI driver, would that cause a problem?

 

[Markfw]

What I meant by unplugging the monitor, was that sometimes monitors have a high pitched whine in gui mode, and if your ears were fooling you, the monitor could have been making the noise, not the PSU.

 

[GreenGrinch]

No.. it's definitely the power supply making the high pitch noise, coz I put my ears right next to the exhaust fan of the PS.

 

[GreenGrinch]

guys.. anybody else has any thought on this??

another thing, what's really funny is, when i'm playing game (w/o sound), the noise is gone! even when i'm running 3D mark, the noise is gone during the test, but it's there in between the test description. So this is really weird... why is the noise gone when the vid card is under load? so which one is defect here? VGA or PS? HELP!! thanks guys!

 

[specktre]

those enermax PSU fans have temperature control so my guess is that it is the fan being turned to a higher speed or RPM because of the PSU getting hot.

I would change the PSU fan out with a sleeve Bearing high CFM low rpm fan. that would solve the problem.