iMac fans are running at their MAX speed.

[iMacBoy]

iMac 12.5"
Late 2009 Model
Running Mac OS Lion

So, a while back my hard drive failed on my iMac, so i replaced it with a 1TB hard drive. It all works fine, but after i screwed it all back together and put the screen back on, the fans after about 15 mins of use on the iMac (using nothing but the internet) the fans MAX out and are as loud as it gets.. when i say loud, i mean it.

(This is the first time i have ever 'changed' anything on a Mac)

Does anyone have any ideas how to fix it? Here's what i thought, but i though i would ask the pro's before i attempted anything.

1. Open the iMac again and make sure the temperature cable is connected to the hard drive correctly.
2. Get 3rd party software that will control the speed of the fans. (This way worries me simply because i have read online that people can't install it and it messes up the speeds of their fans etc)
3. Well.. there is no number 3, does anyone have any ideas?

Thanks
-iMacBoy

 

[LostSoul80]

Try resetting the SMC. http://support.apple.com/kb/HT3964
You can also try with my signature, and absolutely don't worry about it messing up things.

 

[iMacBoy]

Try resetting the SMC. http://support.apple.com/kb/HT3964
You can also try with my signature, and absolutely don't worry about it messing up things.

That link took me to apples 404 page?

Ill try the link in your sig but i would like the try other ways before turning to software to sort it out.

Thanks!

 

[mmomega]

If everything is connected properly and the fans are still blowing at max then the temp sensor may just not be working correctly.

You can use this app as a short or long term fix. I've used it on both of my iMacs after replacing the HDD's with SSD's.

http://exirion.net/ssdfanctrl/Site/SSD_Fan_Control.html

 

[simsaladimbamba]

That link took me to apples 404 page?

Intel-based Macs: Resetting the System Management Controller (SMC) (Apple Support Site)

If the first link does not work, as the Apple Support Pages are bit funky these last weeks:
Intel-based Macs: Resetting the System Management Controller (SMC) (PDF from that Apple Support Page about resetting the SMC)​

 

[Exirion]

If everything is connected properly and the fans are still blowing at max then the temp sensor may just not be working correctly.

You can use this app as a short or long term fix. I've used it on both of my iMacs after replacing the HDD's with SSD's.

http://exirion.net/ssdfanctrl/Site/SSD_Fan_Control.html

http://exirion.net/ssdfanctrl

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