Weird buzz coil / high pitch noise coming from mobo or power supply

dheffer

Senior member
May 26, 2004
736
0
0
Hey guys,

Just recently I upgraded my SLK-948U / panaflo 80mm L1A to a XP-120 / yate loom medium speed combo, along with upgrading my nv silencer 5 on my 6800 ultra to a vf700. Everything has worked out great for me, and seems to be much quieter, but in doing so, I think I've uncovered something else. There is a quite loud, very high pitched noise coming from my motherboard area - not quite my cpu area, I think to the left of it, but not quite where my PSU is. My motherboard is an MSI K8T A64 board, with a 3400+ cpu, and the PSU is a ocz modstream. I thought that this might have been the psu fan, so i also changed the fan to a yate loom medium speed (it was a high speed model stock), and the noise remained. My computer is now pretty darn quiet, with only those two fans, along with another medium speed yate loom, all running at 5V in my foamed 3700BQE. I'm really discouraged. After searching over the forums, all that I've gathered is that it's some kind of buzz coil noise in my psu / interfering with my motherboard. I've tried swapping out the motherboard, the ram, and the video card, with alternatives, and I've even stuck my hard drive / cool drive 2002 in my desk drawer, and those components definitely have not caused what I'm talking about. I've tried searching a bunch on this, and I'm assuming that it has to do with my PSU not having active PFC, but I really didn't think that it made this noise... it's really rather annoying, and it's giving me a headache... so before I go out and buy a new power supply, any thoughts on the matter anyone? Thing about it is, I was working on my computer about a week ago, and I definitely didn't notice the noise, and I'm just wondering what it possibly could be. I've checked the mobo bios to check the readings, and all of the voltage levels are within 1% of spec - I know this isn't perfectly accurate, but I really don't think it's just my power supply dying, or whatever.

Full Specs:
MSI K8T mobo
AMD 3400+ 2.4ghz 512kb cache
XP-120, 120mm yate loom medium speed @ 5V
OCZ modstream, 120mm yate loom fan swap medium speed @ 5v
Case fan, 120mm yate loom rear case fan medium speed @ 5v
Leadtek 6800 Ultra, vf-700 @ 5v
Zalman Fan Controller - what I use to undervolt everything - could this be making the buzzing noise with the power supply - I remember hearing about PWM noise, and was wondering about this?
Sound blaster audigy 2
Hitachi hg720 deskstar in cool drive 2002 CU edition
NEC 2.4x dvd drive (I've tried disconnecting this, too)
Floppy drive (also disconnecting this)
I think thats everything... please get back to me guys, I have no idea what else to try / do...
 

dyle

Junior Member
Sep 14, 2004
22
0
0
Also have the same problem with a Shuttle AN35N-Ultra board. I get a constant buzz/whine when cpu is in idle that goes away when the cpu is on load.

Also have a different whine that's coming from the onboard ethernet port.

Things I found out so far:

1. Sound only starts when computers goes into windows.
2. Sound does not start on Windows login screen. While on Windows login screen, connecting and disconnecting a usb mouse starts and stops the sound.
3. Sound temporarily stops when an audio file is played or sound effect is played by the system..then restarts after a few seconds.
4. sounds come through speakers and from case.
5. Narrowed it down to the motherboard. I am pretty sure that this is not a power supply problem.

Hope somebody can provide some possible solutions too.
 

Operandi

Diamond Member
Oct 9, 1999
5,508
0
0
It's electromagnetic resonance, it doesn?t necessarily mean anything in your system is deing. Most likely it's being caused by your PSU, MB or video card or a combination of those interfering with each other. Try swapping out the PSU and see if the noise remains.