Extreme cpu fan noise on iMac 27" i5

Discussion in 'iMac' started by hallaisen, Jan 11, 2010.

  1. hallaisen macrumors regular

    May 28, 2006

    I picked up an i5 27" from an Apple Store in Toronto today, and was hoping that this would finally be the first time in my life I'd get a problem-free Mac on the first try, but much to my dismay the first thing I noticed when I turned it on was a LOUD noise coming from the lower left side of the computer. It is EXTREMELY annoying, and you can hear it from several meters away. I am currently playing music to try to overpower it, but it is actually ruining the music as well.

    My first thought was that one of the fans is the root of the problem, and a quick test with smcfancontrol confirmed this. The sound is not a wooshing sound, but more like an extremely rapid ticking or maybe even the sound of the fan hitting another component during each rotation. I could locate the exact source of the sound with smcfancontrol, as increasing the minimum speed of the cpufan increases the frequency of the sound. I called Apple, and they said it is most likely a hardware error, and that I'll get a new iMac if I go back to the store where I got it, but it's a 3 hours drive away, and I don't have time to go until two weeks from now. Therefore I want to check out all other options first. Everything else works fine, but the sound just makes me want to punch the monitor as hard as I can, so if there is a way to fix it I would be happy to keep the computer. Anyone got any tips?

    PS. The sound disappears in standby mode fwiw.
  2. djcorrosive macrumors regular

    Feb 22, 2009
    Brisbane, Australia
    turn the fan speeds lower, or just get a replcement, the one i had before i sent it back was perfect (just had dead ram, apart from 1 stick)

    And it was whisper quite, and its summer here and was about 33degrees in my room and it was still quite.
  3. hallaisen thread starter macrumors regular

    May 28, 2006
    Yeah, I'll get a replacement unless I can fix it myself somehow, but it's just annoying to wait 2 weeks to get it replaced. I wanted to get an i7 anyway, but didn't want to wait two weeks to have it shipped, so it's a bit of a disappointment to not have to wait anyway and still not get what I want, and spend another day driving back and forth to the Apple Store.
  4. hallaisen thread starter macrumors regular

    May 28, 2006
    Update: Got my replacement yesterday, and it's perfect so far. The difference is astounding, and I can now use my iMac without noise-cancelling earphones and music to drown out the fan-noise :D
  5. chas0001 macrumors 6502a


    Sep 18, 2006
    Alicante, SPAIN
    I have the same problem too with my 27" i7. Sounds like the CPU fan is hitting something as its spinning. Its really annoying. Its a replacement (bad screen on the original) and I have only had it 2 weeks. Called Apple and they are going to replace it again. I am not that impressed with their Quality Assurance but their customer service is excellent.

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