PC makes buzzy sound for a few mins after booting

[purple buzz]

Ever since my video card started freezing my system, and after I replaced different cards, my system started making a buzzing sound when I boot up. First when I used my old ATI Radean 9500pro (its old and would freeze after about 5 mins), then I tried other new cards and it would still make that sound. now I'm running GeForce 5500 and just 5 mins ago It booted to windows, then restarted my system, then gave some weird blue screen error and rebotted again when going into windows. Then my monitor was a sleep so I had to turn pc off for a few mins. When I booted again i changed BIOS settings in "Primary VGA BIOS" to AGP VGA Card (it was always on PCI but Im running VGA so...)

I dont know if that made a difference but my PC is working now.

What do you guys think this is. Could it be the motherboard? I tried Radean 3650 and it still had that buzzing sound on that too. I am looking to upgrade to GeForce7600 GS but don't want to kill the new card if my motherboard is tripping. Please give me some input if possible.. thanks.


ASUSTek Computer INC Mobo (A7N8X Deluxe)
AMD Athlon XP: Thoroughbred, Socket A 2700+
3 gigs of RAM (Corsair 2 sticks regular of 1 each, and the 3rd XML)
GeForce 5500
200G Seagate (Master)
500GB Wester Digitital SATA
LG DVD Writer
Coolmax AP-550X Power Supply
WinFast TV2000 XP Expert WDM TVTuner
3 fans (2 in the back and 1 on the side)
92mm fan is dead on top but i wanna get another one for cooling

 

[scatrdfew]

I had an ASUS board that made a whining noise when it was powered on, almost like a capacitor was going out on it... however after two RMAs to Asus it was determined to be a problem with the North Bridge chipset causing high frequency humming. Very annoying and Asus decided to replace my motherboard. I like their products but I'm hesitant to try another Asus board now. I have bought two Gigabyte boards and they're pretty decent so far.

 

[purple buzz]

I c... but see this mobo I had since I built this PC which was in 2003. and it only started doing this when my video card started tripping...

it just does that noise for 3 mins then goes away, but i didnt expect it to reboot my pc and all...