Drakey, when your comp is on, you can hear the fan whooshing noise. Thus, you have to worry if the damned noise is missing. Happened to me once, and this is what had me find the problem in a tick !
Besides, you have two fans in your machine, a general fan and a smaller one over the processor on the motherboard. Small chance that both go down at once.
Good luck !
------------------
The world is my oyster !