I don't really know what you call that fan present on the backside of the cpu where you join in the main power, SMTP Fan????? Been facing this problem since yesterday. The fan on the backside produces some strange sounds that it normally shouldn't of course i can't write to you how it sounds but it like keeps getting loud and then goes down and sometimes theres no sound. I did open the box up and check if the screw were loose and clean the fan but when i put it back on the problem still exist. So is the answer like i have to shelled some bucks and get a new one?? Suggestions please.........