With any noise, just follow your ear. While a fan can be the noisy source, many times a dirty fan which becomes unbalanced is noisy and after a minor cleaning is OK. Also, the fan noise can come and go plus there are more than one fan in any typical system, check the power supply. Last on fans, when dirty cpu fan its possible that higher rpm operation is present as the dirty HSF(heatsink) isn't efficient and to cool the fan runs higher pitched, etc. Blow the system case and brush down as well. The other source of noise is "resonance" of metal-to-metal contact or plastic to everything in the system. A minor rap/tap helps detect the source to include covers. To determine noise source, remove side cover and detect away.
My 3-month old desktop has developed an intermittent low volume high pitched buzzing noise that is driving me crazy. Sounds a bit like Morse code except there are very few breaks. First noticed it a week ago and since then it comes and goes, usually lasting for only a few minutes with some 1 or 2 second breaks, but today it's been going for the last 3 hours, still with the breaks. No new hardware/software added recently.
The model is an HP Media Center M8200N with 3GB RAM, 3GHz CPU.
Has anyone else experienced this or can suggest a cause/remedy?
HP Online Support suggested a faulty fan but it's not a noise I would associate with a fan, and the computer case is cool to the touch.
Would appreciate any advice.