non-stop fans

Discussion in 'MacBook Pro' started by otro.tiago, Jun 21, 2010.

  1. otro.tiago macrumors newbie

    Joined:
    Jun 21, 2010
    #1
    Hello there. i have a problem and maybe you can help me.


    i'm having problems with my fans. they never stops running at high speedy. always at 6k rpm, bove of them. the temperature of my mac is really ok, now it's 44 celcius. in brazil it's winter time, there is no sun in my mac!

    just after turn it on, the fans start at this speedy and never stops. the noise is making me problems, cause i'm audio engenering and i cannot record anything with the fans like that. they should calm down.

    i tried to reset smc, i tried to use fan control softwares, i tried to right down into the terminal lines to determine the maximal speedy, but nothing worked.

    in two days i'll record a professional orchestra, and the maestro is going to pee on me if this noise remains.

    do you have any idea to help me?


    thank you very much


    tiago de mello
     
  2. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #2
    You may have a faulty temperature sensor. Your Mac includes 6 or so sensors monitoring the hard disk, the metal case, etc. If the sensors start giving bad readings, the Mac can go into "fail safe" mode where it runs the fans at full speed to protect against possible damage.

    If you run the Hardware Test software included on your install DVD it should show up whether there is a faulty sensor. Sensors are cheap and quite easy to fix - but you might need a professional to open up your Mac to do it.
     
  3. AlphaDogg macrumors 68040

    AlphaDogg

    Joined:
    May 20, 2010
    Location:
    Boulder, CO
    #3
    if the computer does not feel warm to the touch, it would probably be a malfunctioning temperature sensor. if you need a quick fix, just download smcfancontrol and lower the fan speeds to around 3500rpm. after you record a professional orchestra, you can take it in to be fixed. here is the link for smcfancontrol: http://www.eidac.de/?p=134

    edit: ignore this post, i just read that you tried fan control software... pardon my ignorance :eek:
     
  4. iSpoody 1243 macrumors 6502

    Joined:
    Jun 29, 2008
    Location:
    Australia
    #4
    maybe there is allot of dust built up in the fans/heatsink.
     
  5. AlphaDogg macrumors 68040

    AlphaDogg

    Joined:
    May 20, 2010
    Location:
    Boulder, CO
    #5
    you didnt mention what mac you have, and how old it is. I recently took apart my 2.5 year old white macbook, and i was faced with cakes of dust. I removed this dust, reapplied thermal paste to the heatsink/cpu and now it runs about 25ºC cooler.
     
  6. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #6
    Dust might be a problem, but I doubt it. OP's CPU temperature is only 44 C which is quite cool so the air flow looks pretty good. The CPU would need to be a lot warmer to get the fans to 6000 rpm if the fan control feedback loop was working properly.

    I expect a sensor failure is much more likely.
     
  7. otro.tiago thread starter macrumors newbie

    Joined:
    Jun 21, 2010
    #7
    Thank you for replies.

    The iStat reads eight temperatures in the hardware, and all of them are about 19 to 43 celcius. my install cd is in another city. with me i have only the installation of leopard snow, is it possible to use this cd to do the hardware test? i tried to reboot pushing 'd', but nothing happened...


    i have cleaned up the hardware, there is no dust, and i have reapplied the thermal paste. yes, there is possibility that i did it wrong, but the fan was roaring before doing that, and now it is ok, but it doesn't stop.

    and yes, the mac is cool in touch.

    oh, my mac is a Macbook Pro 2.33 Ghz, 4GB of Ram, and 3 and a half years of hard use.
     
  8. xi mezmerize ix macrumors 6502a

    xi mezmerize ix

    Joined:
    May 24, 2010
    Location:
    Maryland, USA
    #8
    I too have felt the wrath of urine from an angry maestro...:eek:
     
  9. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #9
    You say the fan doesn't stop.... they never stop on Macs, they idle at about 2000 rpm. Is yours at 2000 or 6000 rpm? 6000 is wrong, 2000 is OK.

    On some Macs there are one or two sensors which iStat does not "see". In particular there is one on the heat sink near the fans which iStat does not report. If this sensor is faulty the fans will run at >6000rpm.

    Read this thread, the OP had a similar problem and we diagnosed it to an unplugged Heat Pipe sensor.
    http://forums.macrumors.com/showthread.php?t=887619

    I think you need the original install disks to diagnose this problem. Can someone send them to you? Or can you get to an Apple store?
     
  10. otro.tiago thread starter macrumors newbie

    Joined:
    Jun 21, 2010
    #10
    OK, here it is: it's fixed.

    You were completely right: the cable of the heat sink's sensor was broken. it was kind smashed, kind smelted, very serious damage. Then, i took my tools and solded it... very bad, indeed, but the minimum to get it work.

    then i turned on the computer and here it is: now, both coolers running até 2000 rpm, at 49 degree. Before, it was 6000 rpm.

    Well, thank you for telling the problem would be in one heat sensor. And hope help people with future problems.

    Yours

    Tiago de Mello
     
  11. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #11
    Glad you fixed it. I'm sure your soldering will hold up well. If not I expect it's only a few $ for a new sensor.
    Hope the maestro is happy now.
     

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