CX400W gives off high-pitch whine

[bugblatter]

I found some posts here with similar problems but not exactly the same, so I decided to write a new one.

 

I recently bought a new HP p6110t computer that had a built-in 250w psu that seemed pretty weak, so I decided to upgrade it to the corsair cx400w. As soon as I installed it and flipped the psu switch on to "I", it began to emit a high-pitch tone/buzz that wasn't very loud but noticeable. This is before turning on the computer, so nothing else is going on, and it is obvious the sound is coming from inside the psu. The psu fan is not turning either, as expected, so it can't be fan-related. The sound continues after turning on the computer. With the computer off, if I turn the psu switch off to "0", the sound continues for a short time before dying out, making me think of a capacitor that is discharging. By comparison, the original psu did not make any sound, so it cannot solely be a motherboard problem.

 

In trying to debug it, I noticed the following. I tried the paper clip test with a hard drive connected as a load: there was no whine and only the fan was turning. The sound appears once you connect the 24-pin cable to the motherboard. I tried connecting the 24-pin cable to a pentium 3 motherboard in an old computer and got the same high-pitch sound (computer off).

 

Is there a problem with the psu? The sound might be tolerable, maybe, unless it gets worse over time or during certain loading scenarios. Then again, I mostly notice it when the computer is off, which would drive me crazy in an otherwise quiet room. I could return it, but could the replacement have the same issue? Thanks in advance for any help.

[RAM GUY]

Let's try to get it replaced, please use the On Line RMA Request Form and we will be happy to replace it. Be sure to check the box that says “I've already spoken to Technical Support and/or RAM Guy.”