My computer had a lot of dust in it so i took it to my truck where i have an air compressor hooked up. I shot air onto the motherboard to clean out all the dust and crap. When i passed over the CPU fan, it spun really fast and sounded cool so I charged the tank up to 80psi then gave full blast at the fan for less than a second. The fan spun extremely fast, made a deafening high pitch tone then BOOM 2 of the fins broke off!
After the fins broke, I took the computer back up to my room and turned it on. Guess what, the CPU fan doesn't even spin anymore lol. It sort of resists, I think I totaly destroyed the bearings on it

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My computer is still an Athlon though so I'll have to shut the puter off after this post, case fans just won't keep it cool enough.