Mac fan really loud

[Runeshadow]

I was using my mac, And it powered off, so I rebooted it and the fan was really loud, And so I turned off my mac for the night, and I come back and turn it on and it is still really loud, Please help, It is REALLY annoying, Thank you.

 

[Spike88]

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When an iMac gets "too hot" (way too hot), it does "last resort" auto-shut down process. When it over cooks its insides &/or does an emergency shut down, its SMC settings can become scrambled. Thus, its fan can be set super fast RPM - when the iMac is restarted. Scrambled SMC settings can be one of negative rebound effects of emergency shut downs - from being too hot.

To reset SMC (and its brains), surf: http://support.apple.com/kb/ht3964

As a suggestion, also install iSlayer iStats Nano ( http://www.islayer.com/apps/istatnano/ ) or iStats Pro (both are free widgets) and monitor your iMac's internal heat and internal fan RPMs. If you see any fan stuck on 0 RPM, then that specfic fan needs to be repaired / replaced. If you see the HD starting to go above 60C, then its insides are being over cooked. Apply "proactive" cooling measures to keep its insides cooler...

Hope this helps....

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[Runeshadow]

Thanks.

That helped ALOT. I didn't get the page you replied, I dont think it even said how to reset, but I just google searched and found it.


For those who find this thread via google or something, to reset the smc requires 5 steps,

[1] Shut down your mac.
[2] Unplug the power cables.
[3] Hold the power button for 5 seconds and release.
[4] Re-plug the power cables.
[5] Re-boot the mac as you would normally

If this doesn't work, Idk how to help.