Halp :(

[evanz]

its dead, immediately turn comp off, go get a new fan
if you dont turn it off, your cpu will fry

or

possibly a failure in the motherboard fan control

can you test the fan on another comp

what happens when you turn comp off and try to restart it, does the fan have a jitter start but then stops?

try this , with your finger try turning the blades, does it feel like its biting and not smooth to turn, if so then the fan bearings are gone, need a new one