My fans are going crazy..

Discussion in 'MacBook Pro' started by mfaye21, Jun 6, 2010.

  1. mfaye21 macrumors regular

    Joined:
    Aug 29, 2009
    #1
    Hi,
    I love my mbp half to death but for the past few days my fans have been going non stop. They are currently at 4965 rpm doing just web browsing. Should I get this checked out?
     
  2. spinnerlys Guest

    spinnerlys

    Joined:
    Sep 7, 2008
    Location:
    forlod bygningen
    #2
    Open Applications / Utilities / Activity Monitor and select to SHOW ALL PROCESS and sort by CPU use.

    Then report back if any process is hogging up the CPU.

    Btw, what is the temperature of the CPU (in Celsius and Fahrenheit)? What application does say that your fans are running at those speeds?
     
  3. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #3
    Things to check
    - reboot & don't start any programs - fans still fast?
    - in Activity Monitor, when you have no programs open the CPU should be mostly idle (about 90% idle), if not you have a rogue process (eg Flash)
    - download iStat Pro and check your temperatures. At idle CPU should be 40-60 C (depends a bit on what model CPU/MBP you have). All other temps should be lower.
    - run Hardware Test on your install DVD. Sometimes a faulty sensor can cause the Mac to go into "failsafe" mode where it runs the fans full speed. HW test would show a failed sensor. Sensors are pretty easy & cheap to replace though!
     
  4. mfaye21 thread starter macrumors regular

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    Aug 29, 2009
    #4
    I am using Istat pro to know. And I didnt really see anything in activity moniter that popped out..
     
  5. spinnerlys Guest

    spinnerlys

    Joined:
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    Location:
    forlod bygningen
    #5
    Again: How hot is the CPU?
    And have you selected to SHOW ALL PROCESSES in Activity Monitor?

    And have you taken the steps Pax recommended?
     
  6. stridemat Moderator

    stridemat

    Staff Member

    Joined:
    Apr 2, 2008
    Location:
    UK
    #6
    Did you sort by all processes and by selecting the CPU header to organise from highest to lowest?

    Should be as the screenshot

    [​IMG]
     
  7. mfaye21 thread starter macrumors regular

    Joined:
    Aug 29, 2009
    #7
    Yes they are still going crazy. I followed PAX's advice. Here is a screenshot of my activity monitor..
     

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  8. McGiord macrumors 601

    McGiord

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    Dark Castle
  9. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #9
    OK so your Activity Monitor screen looks OK.
    What about your temperatures as reported by iStat Pro?
    ... if you could take a screenshot of the iStat Pro temps....
     
  10. mfaye21 thread starter macrumors regular

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    Aug 29, 2009
  11. McGiord macrumors 601

    McGiord

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    Oct 5, 2003
    Location:
    Dark Castle
    #11
    where are you? now is summer time in many areas of the world, so higher temps might be surrounding your mbp. what is your room temp?
     
  12. mfaye21 thread starter macrumors regular

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    Aug 29, 2009
  13. hockey9999 macrumors member

    Joined:
    Mar 11, 2010
    #13
    Did you try resetting the SMC?

    http://support.apple.com/kb/HT3964

     
  14. Works4Me macrumors regular

    Joined:
    Aug 29, 2007
    Location:
    Canada
    #14
    This probably doesn't help the OP, but thanks for the heads up about selecting "All Processes" in Activity Monitor. Some background process in TechToolPro was hogging the CPU (showed 100%). I deleted it, and within minutes, the fans had spun down from nearly 4000 rpm to around 2000, and the temp dropped from about 80 C, to 62-64! So glad to have solved that problem!
     
  15. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #15
    @OP
    Ignoring the CPU, your internal temperatures all seem quite high:-

    Your enclosure base is 35-36 C, much hotter than mine at 28 C
    Your Northbridge is very hot at 53C compared to mine at 35 C
    Your HDD is at 38 C vs mine at 30 C
    Your heatsink is also hot (mine at 43 C)

    I suspect something is blocking the fan vent. Even though your CPU is definitely idle or near-idle the internal temps across the whole computer are quite high. Most of the heat seems to be soaking into the computer internals. This is not the way it is supposed to work. The only hot part inside the MBP should be the CPU and heatsink, then the fan should suck the heat straight from the heatsink.

    I think Apple sets the fan algorithm to try to keep the CPU, the Northbridge, the enclosure and the HDD cool. Each has a threshold temperature. If any of them go over threshold the fan speeds up.

    I suspect the fan is working hard to try to keep the enclosure or HDD cool, not the CPU.

    I would talk to Apple, I think you may have a minor problem. If you are electronics-wise and out of warranty you might want to take it apart and look at the airflow path.
     

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