electronic (unwanted) noise from speakers
 

Hello,
I built a computer from components some months ago, and am tackling the issue of why speakers (which worked fine on a previous computer running Linux, only a different distro - Red Hat 9) make an ominous buzzing noise when they are powered up and connected to the computer. They do NOT make this noise when powered up and not connected.
Motherboard is Intel D865PERL; 865PE chipset. Is supposed to have integrated sound. Computer currently only has Mandrake 9.2 installed.
What I am asking for here is for a list of things to look for, as sound is my weakest area. I was not able to find anything helpful in the manual that shipped with the motherboard. I do have a couple of Linux books, but due to the constantly-changing hardware landscape, they do not offer anything that would give me a checklist or any useful way to troubleshoot my problem -- and I have tried! Please advise, thanks. TudeCat

if it's a onboard one, this can mean trouble or a driver/freuqency related problem. volume? output line?
pci [mech]
try another slot; try reducing electromagn. influences (bios, empty pci-slot / timer); or by shielding the card (which will hardly work ;).

sl mritch.