occasional chirp in hard drive - macbook pro 13

Discussion in 'MacBook Pro' started by joaomario, Jul 17, 2011.

  1. joaomario macrumors newbie

    Joined:
    Aug 7, 2009
    #1
    Hi. I've got a macbook pro 13 2010 model with a 250gb stock hard drive.
    i've recently noticed that when i carry my laptop around the house (whilst on) and casually put it down on the sofa or other cushioned surface i hear a little chirp which i believe is coming form the HD.
    has anyone noticed this on their computers? I'm not exactly easing it down gently but not throwing it down from a great height either. I'm "dropping" it from about 5-10cm(2-4inches) or so. One edge of the notebook contacts the surface first and then the rest touches down on the sofa. I think i'm being gentle with it but the chirp is concerning. Do you think it's the drive heads scratching the drive platter? It's happened a few times now. does anyone else have this happen to them, can it be something else?

    more importantly: is there a hard drive utility out there that can scan the hard drive and determine if i've damaged/scratched it? it can be on osx or windows as i have both on my mac. I've already "verified" my drive with osx's disk utility without problem but i want a better scan.
     
  2. appleguy123 macrumors 603

    appleguy123

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    #2
    Nothing is wrong. It's the sudden motion sensor that prevents your hard drove from failing during a drop.
     
  3. ZZ Bottom, Jul 17, 2011
    Last edited: Jul 17, 2011

    ZZ Bottom macrumors 6502a

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  4. joaomario thread starter macrumors newbie

    Joined:
    Aug 7, 2009
    #4
    hi appleguy, thanks for your response. are you certain? does the sudden motion sensor really sound like a chirp (or squeek)? i thought it would sound like a click instead, as the head parked....can the sudden motion sensor activate so quickly and for such a slight drop?

    is there any app i can use to check drive just to be sure?

    You're response was/is much appreciated.
     
  5. Lennyvalentin macrumors 6502a

    Lennyvalentin

    Joined:
    Apr 25, 2011
    #5
    Answer A: don't deliberately drop equipment containing harddrives - ever. Particulary not onto hard surfaces. A harddrive is a precision instrument with incredibly tight tolerances that aren't allowed to cost very much, meaning they usually work quite well, and if you're unlucky it's going to fail spectacularly. Best not provoking Murphy by dropping it, nothing good will come out of it even in the best of times. :p

    Answer B: the head assembly actuator is actually a voice coil, similar to what you find in a speaker. The chirp you hear is almost certainly not the sudden drop sensor per se, but rather the sound of the voice coil responding to the sensor's indication you're dropping the laptop, retracting the heads off the spinning platters onto the head-ramps, to prevent damage to the drive.

    The sensor is most likely a MEMS accelerometer, they're very sensitive and reliable solid-state CMOS devices (like a microchip). It might not actually be mounted in the macbook, many modern harddrives have these devices integrated directly, as they're so sensitive they can measure and help compensate for the vibrations from the drive's spindle motor, or the spindles of adjacent drives. This improves tracking, speeds up seeks and reduces seek errors.
     
  6. appleguy123 macrumors 603

    appleguy123

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    #6
    Yes, every MacBook Pro I've ever used has done this. A chirp is exactly how I'd describe it. And it acts over the slightest movement.
     
  7. joaomario, Jul 17, 2011
    Last edited: Jul 17, 2011

    joaomario thread starter macrumors newbie

    Joined:
    Aug 7, 2009
    #7
    Wow, thank you chaps for both of your thorough and reassuring responses. I was worried I could be damaging my hard drive and the consequences of my actions would come to haunt me as drive failure in the future. After appleguy's confirmation that he hears the same chirp himself and Lenny's detailed technical explanation of how these drives work I feel very much at ease.

    I'm grateful to you people who read these forums and invest their time for other people's benefit.
     
  8. MJNBGA macrumors regular

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    Mar 26, 2011
    Location:
    New Zealand
    #8
    Oh yes,I get this in my 2011 13 incher. Quite normal. :)
     

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