Why is my G5 power imac fan running past and loud when im browsing the internet specially when running video, livestream and downloading
Because the CPU is working with a heavy load which generates heat!
If this is a non iSight G5, remove the back, and using a can of compressed air, blow out the dust on the vents at the bottom of the iMac, and the fan, and everywhere else.
Doing this allows enough air flow that the fans won't run at high speed.
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