What does BIOS show as far as CPU Temperature and CPU Fan?
Does it show a CPU Fan error?
Is the CPU Cooler installed correctly on your processor and is the Fan running without Air Flow interference?
In my BIOS with the CPU Fan is not working I get an immediate CPU FAN FAILURE warning. Is that what is showing on yours?
That warning is probably saying the CPU is overheating and needs to be checked. If the CPU Fan wasn't working your computer would shut down within seconds to a minute due to the processor from being damaged due to overheating.