Late 2009 iMac fan always full speed

Discussion in 'iMac' started by deafgoose, Oct 21, 2011.

  1. macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #1
    Here are the iStats of my iMac.

    [​IMG]


    Even after turning off my iMac all night long, the fan speed will be very high after I boot up.

    I have another iMac (same model) that is always quiet. WTF?

    I tried using smcFanControl but it does nothing.
     
  2. macrumors Westmere

    GGJstudios

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  3. simsaladimbamba

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    located
  4. deafgoose, Oct 21, 2011
    Last edited: Oct 21, 2011

    thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #4
    Yes I have tried SMC reset. No luck. Even when I put it in sleep mode, my fan stays on. :(

    It seems to be my Optical Drive Fan that is running at 4,348 rpm.

    That is what it says in smcFanControl v2.3

    [​IMG]
     
  5. macrumors 68040

    666sheep

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    Dec 7, 2009
    Location:
    Poland
    #5
    It could mean that optical drive thermal sensor gone bad. Run AHT in Extended mode. If I am right, you should get an error code related to this part.
     
  6. thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #6
    I can't run AHT.

    I have a late model 2009 iMac running OS X Lion.

    Apple discontinued AHT. :rolleyes:
     
  7. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #7
    You could try this?

    And if that doesn't work, you probably still have your Mac OS X 10.6 Snow Leopard DVDs around to run AHT.
     
  8. deafgoose, Oct 21, 2011
    Last edited: Oct 21, 2011

    thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #8
    I was able to get into AHT mode using the Snow Leopard Application install DVD. The extended test was taking way too long. I will do it tonight before I go to bed and post up the results in the morning.

    :)
     
  9. thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #9
    Update:

    I got a temperature sensor error after completing the AHT.

    4SNS/1/C0000008: T00P--124

    My iMac is out of warranty. What can I expect to pay to have it fixed by Apple?

    Could I just purchase the sensor and replace it myself?

    [​IMG]
     
  10. macrumors 68040

    666sheep

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    Location:
    Poland
    #10
    If you feel comfortable to open up your iMac, then yes, it's doable. You need to remove glass and LCD. Sensor is bundled with cable AFAIK (ask seller before buying to be sure), for 21.5" you need part number 922-9214, for 27" it would be 922-9229. It costs few dozen bucks.
     
  11. deafgoose, Oct 22, 2011
    Last edited: Oct 22, 2011

    thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #11
    Is there software that I can use to adjust the fan speed for the optical disk drive?

    I keep reading that smcFanControl is the best program but the minimum fan speed for my ODD is 4,000rpm? WTF?

    [​IMG]
     
  12. thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #12
    I just got back from an appointment at the Genius Bar armed with all the information I need to order the replacement sensor.

    Turns out they wont let me order it. They need the serial# of my iMac and they also need to do their own test before their system will let them order the part.

    This wont work because I use my iMac for my online business and cannot be without it. WTF?

    So at this point, my only option is to install software to slow down this fan. The only problem is I cant find anything that has control over the ODD fan.
     
  13. macrumors 68040

    666sheep

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    #13
    I'm afraid that no software is able to control this fan when its sensor gives wrong info to the logic board (i.e. fan is working in kinda "emergency mode").

    You can order part here: http://www.macpartsonline.com/imac-parts.html and replace it yourself if you feel skilled enough.
     
  14. deafgoose, Oct 22, 2011
    Last edited: Oct 22, 2011

    thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #14
    Thanks but there are no sensors for sale on that website for a 21.5" iMac

    http://www.macpartsonline.com/imac-parts/imac-aluminum-21-5-inch.html?type_part=105

    If I can find the part, I can replace it myself no problem.

    Edit: Where is the sensor located exactly? I need to figure that out before I order the parts.

    These are my choices:

    661-5172 - Optical Drive
    922-9130 - Optical Drive Data Cable
    922-9120 - Optical Fan
    922-9214 - Optical Temp Sensor Cable
     
  15. macrumors 68040

    666sheep

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    #15
  16. thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #16
    Thanks sheep! You have been so helpful to solve my problem. I really appreciate it.

    I sent them an email asking if the temp sensor is included with the cable. :)
     
  17. macrumors regular

    Joined:
    Jun 8, 2009
    #17
    Sorry to resurrect an old thread, but what ever came of this? I had a strange experience last night with the fans going full blast. But mine corrected by putting it to sleep, leaving it that way while I watched a movie and then when I returned and woke it up, it was fine.
     
  18. thread starter macrumors regular

    deafgoose

    Joined:
    Oct 20, 2011
    #18
    I replaced the optical disk drive temp sensor cable and it solved my problem. :D
     
  19. macrumors newbie

    Joined:
    Nov 12, 2011
    #19
    This solved my problem of fans constantly on high in Snow Leopard. Thanks!
     
  20. macrumors 68000

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    Location:
    Asheville, NC
    #20
    There are a LOT of different things that can cause the fans to go full blast, but it ultimately boils down to the system either thinking that something is overheating or the system not knowing the temperature and running the fans to be safe.

    From the OP's iStat picture, it was clear that the optical drive temperature sensor was acting up, since it wasn't in the list of temperature sensors. Granted, it could still be the logic board itself not seeing the sensor correctly.
     
  21. macrumors newbie

    Joined:
    Jan 31, 2013
    #21
    Not, to rekindle an old discussion, but I have a similar problem with Mountain Lion on an Early 2009 iMac.

    I have iStat Menus installed and when the fans go berserk, I notice that half of the temp sensors go "missing" (they have a "-" in place of their temp). If I reset the SMC, I have a 4/5 chance that the system will return to normal for a period of time, but the sensors and fans will eventually go haywire even if I don't use the computer much.

    I just reset the SMC, so I can't take a screenshot, but I'll add one the next time it happens.

    Is there a way to get the hardware test to burn onto a CD? I cant find the original system disk, and I cannot get it see the supposedly online version from the apple support page.

    What are people's opinions on tools like TechTool Pro, Drive Genius and the like? What happend to the TechTool Deluxe that used to be available for AppleCare?

    - Adrian
     
  22. macrumors newbie

    Joined:
    Jan 31, 2013
    #22
    Screenshots! (It happened again after 30 min of minimal usage..)

     

    Attached Files:

  23. adriandlm, Jan 31, 2013
    Last edited: Jan 31, 2013

    macrumors newbie

    Joined:
    Jan 31, 2013
    #23
    Follow-up:
    After another SMC reset (I hate working with those loud fans), the problem came back after 30 min, but this time it happened gradually. The CPU Heatsink sensor showed "-" first, and on its own. And only the CPU fan went to 100%. Then after 10-15 min, half of the other sensors went kaput in iStat and all fans went on full drive.

    Also, I found my old iMac system disks! The AHT showed no problems on the quick test, and I will run the extended test overnight, as it says it will take a long time.

    (If anyone still reads this discussion, I'd love so help!)

    - Adrian

    Edit: Extended test results (unfortunately, theyre bad)
    Code:
    Alert! Apple Hardware Test has detected an error.
    4SNS/1/40000000: TCOH- 131.000
    What should I do?
     
  24. macrumors 68000

    Joined:
    Sep 10, 2008
    Location:
    Asheville, NC
    #24
    I don't know what the code means, but you could Google it. No software tool is going to fix your issue, since you have a hardware problem. Tech Tool Pro is a complete waste of money, and Drive Genius is almost a complete waste.

    Anyway, the reason your fans are going nuts is specifically because the temperature sensors are going offline. The options are that it's either the SMC going bad or that one (or more) of the temperature sensors are going bad. Yes, despite the fact that multiple sensors are going offline, it's still possible that it's only one. Beyond that, knowing which one is the problem boils down to trial and error. Unfortunately, they intentionally put different connectors on them all so that people can't confuse the system by plugging them into the wrong jack on the logic board, so that also rules out moving them around. Someone is going to have to swap in known-good parts and see what happens.
     
  25. macrumors newbie

    Joined:
    Jun 10, 2013
    #25
    Running Fans May be faulty 1TB Seagate Hard Drive

    Faulty Seagate 1 TB hard drives caused this fan problem on some iMacs. Apple is still replacing them. See this article: <http://blog.macsales.com/15165-apple-extends-imac-hard-drive-replacement-program>
    and Apple's page: <http://www.apple.com/support/imac-harddrive/>
    Hurry, their support could end any time.
     

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