iMac fan on even when turned completely off

Discussion in 'iMac' started by 32gb3gwifi, Jul 21, 2011.

  1. 32gb3gwifi macrumors member

    Jan 29, 2011
    Like my title says my new 27" iMac's CPU fan I believe (the one on the left) won't turn off when I shut down the computer. Now on to the clarification, the fans do not run loud. My CPU fan is at a constant 995 to 998 rpm no matter what I am doing. It's completely silent. The whole computer. BUT, when I turn the computer off and put my ear to the exhaust vent I can hear the motor turning. Unless it's something else clicking. But I am 95% sure it's the sound of a motor turning. Now to the question. Is this normal? For the fan to continue to run albeit completely silent even after a complete shutdown and cool down?
  2. Hellhammer Moderator


    Staff Member

    Dec 10, 2008
  3. 32gb3gwifi thread starter macrumors member

    Jan 29, 2011
    ok so i have figured out something else, when i unplug the iMac the sound goes away and as soon as i plug it back in it comes back. but i have noticed that the fan is spinning MUCH slower when its turned off than when i turn it on. it is still completely silent either way but it spins much faster when i switch the computer on. so when it is off it sounds more lick a faint clicking sound.
  4. frankc23 macrumors newbie

    Jul 18, 2012
    I have the same exact problem after I installed an OWC SSD in my 2008 24inch iMac (8,1). I am certain I correctly attached the thermal sensor to the SSD. Now after shut down or during sleep mode, I can hear a fan (I think it's the fan) still spinning -- again, this is AFTER the iMac is fully shut down. I did a SMC reset and the problem still remains. During normal ON operation, the fan is running smoothly (<1200rpm) and is extremely quiet...same as before.

    Did you ever solve this problem? Would love to hear the solution.



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