511-CPU fan not detected. Help!

[Kr3jTh0s]

Hello!

Whenever I boot up my PC I get a black screen with some components details, a text saying "511-CPU fan not detected" and a blue bar on the lower left side of the screen displaying "Press f1 to boot". My CPU fan occasionally stops spinning and after a while starts spinning again and repeat. It has been going on for about a year and I don't know why I haven't tried fixing it, better late than never.

I recently updated my BIOS to A0.14 but that didn't fix anything. I am afraid to remove the fan and clean out the dust because I don't know if I need to replace the thermal paste. If I simply don't need to replace the thermal paste then I will attempt to clean the fan. 

The fan is connected to the CPU fan plug on the motherboard and don't seem to be loose or broken in any way. I have though inserted another 2GB RAM/DIMM (I don't know what word to use) onto the second DIMM slot. I don't know if that causes any problems but I hope not. 

Any suggestions on what to do? Is it fine to remove and clean the CPU fan without replacing thermal paste? Does a second RAM/DIMM card with different GB cause problems? Do I need to replace the fan?

[old_geekster]

@Kr3jTh0s , welcome to the forum.

I suggest that you take canned air and careful blow it into all of the fans.  This should be most of the dust out of them.  You won't have to remove the fan if this works.