Yesterday, I was using my computer, I think I was looking at stuff online, and for some reason I heard a high pitched wine come from my computer. Restarted it and the noise was still there. The noise is persistent as long as the PSU has power, even if the computer is off. If the psu is unplugged or the switch is flipped then it stops whining though. I opened up my case to see if I could pinpoint the source. After unplugging all of the components including the fans, HDD, CD drives, mobo, etc I figured two things out. First of all, when I unplug the power connector from the motherboard (24 pin) the whine is less audible. Second, Im 99% sure that the PSU is making the sound.
Onto the next problem. Along with the computer whining, the sound is staticy coming from speakers. I did alot to try to fix it: upgraded firmware, reinstalled firmware, tried a different pair of speakers that work fine on other computers, and even took my speakers out and tested them on another computer. I also upgraded the BIOS and mobo drivers as well. Im out of ideas and if anyone has anything to say then dont hesitate because Im getting annoyed with these problems.
I made the computer last August, and Have upgraded it to Windows Vista Home Premium.
It has the following components:
Intel DG965RY Motherboard
Intel E6300 Core 2 Duo Processor
2 GB DDR2 RAM
320 GB SATA HD
NVIDIA 7600 GT Graphics Card
Hauppage WinTV tv tuner PCI card
Creative 2.1 Speakers
Belkin USB wireless card
Antec TX1050B case
Antec SP-500 PSU (500 watts)
Lite On DVDRW Drive
Lite On DVD ROM drive
Media Card Reader
Thanks,
BDR31693

From your descriptions it must be the PS that is making the high pitched noise. ATX PSs are always powering the ATX mboard as long as they have AC power to them, even when Windows is Shut Down or in Standby or Hibernate modes.
Antec is a very good PS maker, but any PS can become faulty or fail - it's just a lot less likely if you have a good make of PS.
The staticy sound may also be caused by the PS.
You have a three year warranty. You may have two choices if you get a RMA (Return of Merchandise Authourization) on the Antec website - you can ship it to them using their rules about how it should be packaged, or you may be able to have them ship a new one to you and you ship the defective one back, but in that case you must use a credit card online.
How much it costs to ship and how long you are without a PS is up to you if you ship it to them, depending on how fast you want to send it - if the other option is available, you will get a new PS in a short time and not be without a PS, but the shipping will probably be expensive.

OK thanks, I will contact Antec asap

my psu sometimes makes a kind of high pitched squeel (not very loud) when the computer is off. about 4 yrs old - done it for years.