I have a P4 2.4 Ghz and the stock cpu fan/heatsink. Recently the fan has started to make a wierd humming sound that goes away when I tap it but then comes back a few mins later. When I replace the ...

I never remove a mobo from the case simply to replace a cpu. Between static discharge and grounding issues, IMHO it's better to leave it mounted in the case, assuming it's mounted properly. If it's ...