Replace with Quiet fan (I won't reccomend quiet fans, as anything is quiet compared to my Delta setup (an F16 will get a run for it's money). When funds allow, replace the whole thing. They are, as stated, complete and Utter s**t. I've seen them take out systems, yes, whole systems, when they let go. Hell, I remember reading on the net that one let go, and the whole house burnt down as a result. I've got one in work (550W Dual Fan, and I'm a tech), and when replaced with a generic cheap(15 quid), one, all problems with the system magically go away. No need to go nuts on one, a nice Jeantech or Fortron Source (Same thing), will see you good, and they aren't hellishly expensive.