PSU fan speed does not vary...any more
 

My PSU fan speed USED to reduce shortly after startup. Now it sounds like it runs at MAX speed ALL the time....:uhoh:
Any ideas??

Have you checked inside + all the vents for a build up of dust clogging vital airways?

If you do go inside, then don't forget the leading edges of the fanblades. (Lots of gunk can gather there and spoil the airflow) After all, this is an aviation based site, I suppose...

Conan

Computers require regular cleaning, especially in a dusty enviroment. Buy a can of compressed air from your local computer retailer for the hard to get spots. If you use a vaccuum cleaner be very careful, you can get a kit with small brushes that connects to the vaccuum hose specialy for cleaning computers and keyboards or hard to get spots. i would say the fan is running at full speed all the time because it is probably accumulated dust which makes it overheat. open the case and clean out all the dust but make sure to earth yourself to the case to avoid static electricity.
Allen

Is the fan temperature sensitive (I have an Antec power supply which adjusts the fan speed as the case temperature varies)?

Could something have happened to causes the temperature in the case to rise? Stuck CPU/chipset/graphics card/case fan, perhaps. Give them all a good clean.

Thanks for the tips - I opened the case and now think that the noisy fan is in fact the CASE fan...it is mounted in the back of the case and connects to the motherboard...
I looked in the BIOS setup but there is no setting for the fan...
I see three fans (besides the PSU fan) in the case (Processor, the case fan and another small one on another chip). These are all clean. I wonder is the fan on the case essential?
Oh well, I will just have to wear my noise-canceling headset at the PC!!
Cheers!

There is normally a small round sticker on top of the fan, Lift the edge of the sticker to find the fan shaft. Place One drop & one drop only of light machine oil on the small bearing. Replace the sticker. This should stop the noise.
Allen

Problem solved!
Downloaded a program called SpeedFan and tried adjusting the fan settings. This must have nudged something else into life - now the fan speed changes with temperature even without SpeedFan running...phewwww! :cool:
Cheers!