I'm having an issue - the PSU (I'm assuming) is making a high-pitched noise while the computer is turned off. The noise disappears if I power down entirely via the switch on the PSU. It also goes away when the computer is fully turned on.
When it started: I installed a Samsung SSD and it's running off the same SATA power wire as a WD Green 1TB drive and another SSD (OSZ-vertex) - trying to keep the number of wires down. I did install Samsung SSD Magician software that's supposed to tune the system and power tuning was one of the features (I tried untuning and turning off - noise is still there).
That whining noise is indicative to a coil possibly going bad. The PSU will still function like that but it may be annoying and I would take it as an indication that a PSU replacement may need to be budgeted as a not too far off purchase here
That seems to be the common answer for a lot of high pitched whines. My main concerns are:
The issue came about when SSD was installed and power-tuned - did SSD cause this and will it do so for the next PSU too?
Does the fact that the noise goes away immediately when computer is powered on suggest that it may be something else (maybe there are some power settings for an "off" computer I'm not aware of)? Just seems to be backwards - why make noise when it's drawing minimum power instead of when it's under load?
Coil whine is described as a high frequency vibration within the coil. Certain load situations can increase/decrease those vibrations - In your case, i'm under the impression it's being caused by one of your lessor voltage rails (such as 5v used for stand by). Once the rail is loaded up, the vibration frequency changes, rendering the noise inaudible.
Doesn't help the situation I know but there is not much (if anything) outside of replacement you can do to get rid of it. If it was occuring while you were under load, you could change the load to possibly get rid of the whine but it whining on standby doesn't leave anything to change.
I don't see how it could be caused by the SSD, unless it is also getting standby power. I suppose you could try unplugging the sata power to the SSD and seeing if the noise goes away (that would suprise me).