Welcome to THF.
Please try to describe the sound! Is it high-pitched, is it a beep, rattle, what?
So, what exactly happened? You heard a funny sound, your fan then went up to 100%, then you couldn't boot anymore? That doesn't sound good...
Did you make any recent hardware or software changes to the computer?
Did you smell anything funny when you opened your PC?
Did you touch any part of the board (or anything for that matter) when you opened your PC?