High frequency "dog whistle" type noise coming from PC

[Van Gogh]

Recently, my PC has been making an irritating super high pitched noise. It's not that loud, but it's sort of like a dog whistle. When the PC is off, I can hear it coming directly from the PC itself. When I turn my computer on, I can hear the sound through my headset, and the noise stops coming from the actual tower. It prevents me from listening to music because it cuts out the high end of all sounds and makes everything sound bad. I've tried switching the outlet and cleaning the inside of my case to no avail.

[Blarg190]

You sure you don't have an internal speaker? When its off? What the piss?
The only thing I can think of is take out the cmos battery and unplug the computer then cycle the power (hold power button).

[Van Gogh]

I'm prob. incapable of doing that.

[Factory]

One of My Pc's Monitors does this.
Luckily, its the Downstairs one.

[matey9]

My old PSU(apevia) made a high-pitched noise when my computer was in sleep mode but I dont recall my headphones being affected.

[Van Gogh]

well, I'm getting a new comp. soon so I'll just wait it out

[reeferdk]

Probably a malfunctioning capacitor..

[url=http://www.google.com/search?q=capacitor+whine]Capacitor whine[/url]

[Rixxz2]

[QUOTE=reeferdk;18732567]Probably a malfunctioning capacitor..

[url=http://www.google.com/search?q=capacitor+whine]Capacitor whine[/url][/QUOTE]

While it's off? Blasphemy.

[rieda1589]

[QUOTE=Rixxz2;18745273]While it's off? Blasphemy.[/QUOTE]

Computers turned off aren't necessarily having no power going through them.

Try unplugging your PSU plug, if it continues then I'd suggest getting an exorcist.

[Van Gogh]

when I unplug it, it does stop. I still have no idea why the whine would come through my headset though.

[reeferdk]

[QUOTE=Rixxz2;18745273]While it's off? Blasphemy.[/QUOTE]

Both the PSU & motherboard and other periphirals can have power while the system is off (Ever wondered how wake-on-lan works eh?)

[Protocol7]

[QUOTE=Van Gogh;18747841]when I unplug it, it does stop. I still have no idea why the whine would come through my headset though.[/QUOTE]

It's probably a capacitor linked to your PCI bridge/whatever bridge controls your sound setup.