Jul 20, 2011
So, I've recently completed a build for a friend of mine and had a few initial errors that I've since sorted.

One however persists. Upon booting up the computer I am greeted by a message stating "CPU fan error" and requiring me to press F1 to enter BIOS config.

All fans are spinning, the CPU fan is without a doubt connected in the right place, temperatures are all fine. Nothing seems to be wrong, other than the error message informing me something is wrong.

If anyone can shed some light on the matter I would appreciate it :)

Ps. This is posted here because I believe the issue is not the CPU fan itself but something to do with the motherboard or the BIOS.


Apr 15, 2010
I have the same problem. Are you using an Asus motherboard? I do and I had the exact problem. Try going into the monitor in your BIOS and there should be a CPU Fan Control which is disabled, if you enable it you can choose the CPU fan speed and a minimum RPM, if the fan drops below that minimum RPM (default is 600) then you will get warnings in windows as well as on attempting to boot. You can solve this (probably) by setting the Minimum RPM or Warning RPm (something like that) to ignore, it will no longer warn you if you have a low RPM or if it thinks you have a low RPM.

Try downloading HWMonitor, the RPM monitor for my fan is completely screwed, it jumps between 0 and 675000 RPM, yet the fan is actually fine. So check to see if your fan monitor gives an accurate RPM as this may be the problem because it jumps below 600 every now and then so I get these warnings.

Good Luck! :)