I have been having problems with my desktop the past few weeks and I can't seem to find the solution. I'm using an Asus P5N-E SLI CPU card and my fan is Aquamaster S1. The fan turns on fine and starts running, lights up etc when I boot the computer. The problem is that upon boot up I get the message saying "Warning: your computer CPU fan fail or set too low". I go into Bios and sure enough Fan1 is running at 0 RPM (Even though it *is* running, I have my case open) and the temperature slowly rises.
The odd thing is that it doesn't even always happen. Sometimes it will boot up without any problems, sometimes it will give the error and the fan will not initiate.
Also, I am very unfamiliar with liquid cooling but the end of the cooling tube that connects to the CPU gets warm/hot when the CPU is heating up, but the part near the fan itself is normal temperature. The part that is actually connected to the CPU board is very hot as well.
One last thing, I took out the aquamaster fan and cleaned it out. (it was filthy I must say) I was hoping that wa