Weird noise

[ninjamonkey]

Hello,
I built a computer like four months ago, but now there seems to be a high pitch noise coming from what i believe to be the powersupply. The powersupply unit is the one that comes with the Antec sonata ii, The 450watt smartpower 2.0.

When the computer is turned on it has a quite annoying high pitch sound coming out of it. When i turn off the power, the pitch changes to a little lower pitch, but it is still there. When I either take the plug out of the wall or flip the switch on the powersupply on the back, the noise stops. So am i right to assume that the powersupply is causing my problem?

So, is there anyway to fix this problem and do you think the psu will blow soon? The sound is very annoying and if it cant be fixed i will probably replace the current unit. I just recently started college and I didnt notice any computer stores in the area so I will probably be getting the new PSU at bestbuy :\ .

I need enough power to run 7900gt, amd 64 3700+, 1 floppy, 1 harddrive, 1 cdrw/dvdrw drive and onboard sound. I assume i do not want to go under 400watts when looking for a new unit. If bestbuy has antec or forton supplies i'll probably get one of those, but if they dont, what other units should i look into getting that will be around 100 dollars?

 

[AMDSCOrPiO]

its probably the hard drive

 

[COD2_fanatic]

you never know, my moms old computer was doing it and it seemed the actually be coming form the CPU (weird i know), but yeah just go through a check phase, like unplug the hard drive and turn the computer on (if the noise is still there try something else), continue that with every device untill you can narrow it down

 

[ninjamonkey]

Update:

Ok i did some more investigating as suggested and came up with the following:

I am 90% sure that it is the psu making the noise. I booted up without the harddrive connected and still made the noise. I unplugged the power to my videocard, still made the noise. When i computer was turned off and still plugged in with the case open, the noise seemed to be coming from the psu. After having it off for a couple minutes still plugged in, the high pitch noise eventually stopped once. I tried this again but the noise kept on going, so i decided to put the computer back together and come on here.

(edit) how can i check if its the CPU, cause that is where my other 10% thinks it could be, but i really dont think it is.

 

[bmxfreakrider]

its probably the psu, u got a voltage checker on ur mobo? run speedfan to find out

 

[ninjamonkey]

i just bought a new psu today. The noise was way too annoying even if the voltage was correct. So problem solved, thanks for your guys help.