MBP Freezes When Lightly Repositioned: TEST YOURS

Discussion in 'MacBook Pro' started by Sherman90, Jan 16, 2009.

  1. Sherman90 macrumors newbie

    Joined:
    Jan 7, 2009
    #1
    I'm wondering if this is unique to system.

    Here is the test:

    1. Load up any movie that is ripped to your hard drive - i.e. DIVX etc.
    2. While playing, lift the laptop in the air a few inches and let it drop gently to your lap. You can also try to firmly "tap" the bottom/front/right of the MBP (where the hard drive is) for the same result.

    Does the movie freeze? Stutter? Mine does.

    I'm led to believe that either my particular HD is overtly-sensitive, improperly installed or defective, or else that the HD is generally too exposed in the Unibody design. I wouldn't find this problematic except that movies freeze and stutter with often the slightest movement while the notebook is on my lap.

    Please post your results.
     
  2. acfusion29 macrumors 68040

    acfusion29

    Joined:
    Nov 8, 2007
    Location:
    Toronto
    #2
    Why would you even drop your laptop, even if it's gently.

    The reason it skips is cause the movie file is constantly accessing data from the source in order to keep showing the picture, so if you bump the harddrive of course it's gonna skip.
     
  3. DoFoT9 macrumors P6

    DoFoT9

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    Jun 11, 2007
    Location:
    Singapore
    #3
    hard drive would be over-sensitive im guessing.

    mine doesnt freeze when i tap it hardly. (yes thats right, i tap it hard all night long haha jks)
     
  4. jjahshik32 macrumors 603

    Joined:
    Sep 4, 2006
    #4
    No problems like that whatsoever and running an intel x25-m SSD drive here. :D
     
  5. mikes70mustang macrumors 68000

    mikes70mustang

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    Nov 14, 2008
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    US
    #5
    wow, seriously. this should be named, "hey i try to ruin my hard drive u should too.
     
  6. kousuke18 macrumors regular

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    Aug 25, 2008
    #6
    lol XD no moving parts ftw.
     
  7. maclover001 macrumors 6502a

    maclover001

    Joined:
    Mar 25, 2008
    Location:
    Vancouver, Canada
    #7
    It's a legitimate question. Especially if you use your computer in the car, or have a severe case of parkinsons :D

    I don't have a unibody MacBook to test, but my SR MacBook doesn't do what you described with an mp4 file from iTunes.
     
  8. DoFoT9 macrumors P6

    DoFoT9

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    Singapore
    #8
    JEALOUS!
     
  9. Sherman90 thread starter macrumors newbie

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    Jan 7, 2009
    #9
    I've owned 4 laptops prior to this MBP and never experienced this before, so I'm prone to think it's not me: it's either the design or the hard drive.

    Just to clarify: I am talking about lifting the laptop up and placing it back down on your lap without the neurotic fears of a converted hardcore materialist.

    I'm handling a notebook not a newborn baby with an iron deficiency.
     
  10. pj- macrumors member

    Joined:
    Oct 31, 2008
    #10
    It's the sudden motion sensor locking the hdd so the head doesn't collide with the platters. That's what it's supposed to do
     
  11. Sherman90 thread starter macrumors newbie

    Joined:
    Jan 7, 2009
    #11
    Does it happen on yours PJ? Did you test it?

    That's what I thought might be happening: I would still consider it a design flaw if it's so overtly sensitive (as mine is).
     
  12. NewMacbookPlz macrumors 68040

    NewMacbookPlz

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    Sep 28, 2008
    #12
    This is what I'd go with.
     
  13. acfusion29 macrumors 68040

    acfusion29

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    Nov 8, 2007
    Location:
    Toronto
    #13
    It's normal. It happened to me and I have a Alu. MacBook with a 5400RPM Seagate Harddrive.
     
  14. pj- macrumors member

    Joined:
    Oct 31, 2008
    #14
    Yeah I can hear the click when I shift mine sometimes. Why shouldn't it? If there's a chance that the hdd could get damaged, I'd rather it be super sensitive than make sure my divx videos play back without interruption. Besides, when my computer is moved enough to trigger the sensor, usually I'm focused on something other than what's on the screen, so what do I care if it freezes for a second?
     
  15. okrelayer macrumors 6502a

    Joined:
    May 25, 2008
    #15
    design flaw or not, you dont typically juggle your laptop while your watching a movie do you?
     
  16. iVeBeenDrinkin' macrumors 65816

    iVeBeenDrinkin'

    Joined:
    Oct 17, 2008
    #16
    I just threw mine through a seven story window and the movie did not stutter at all.
     
  17. macbookproFTW! macrumors newbie

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    Apr 16, 2008
    #17
    this same thing happens to me in a penryn mbp its just the hard drive sensor telling it that its falling and stops itself
     
  18. one1 macrumors 65816

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    Jun 17, 2007
    Location:
    Chattanooga, TN
    #18
    The above poster is correct on the HD sensor, however this drive should be reading ahead and buffering at least ten seconds to allow the HD to recover. This read ahead technology is in EVERYTHING, including ipods from as far back as the beginning. I remember them mentioning it as an actual feature in the earlier HD ipods. It was their skip protection.
     
  19. squaros macrumors member

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    Feb 25, 2008
    #19
    That's a big window
     
  20. aiterum macrumors 6502

    aiterum

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    Nov 17, 2007
    Location:
    United States
    #20
    help i dropped mine gently into a cement mixer what do i do now
     
  21. maclover001 macrumors 6502a

    maclover001

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    Mar 25, 2008
    Location:
    Vancouver, Canada
    #21
    I remember seeing a thread a couple months back about a guy who threw his iPhone out a 20 story just to test out his new case. Of course the thing was totaled.
     
  22. iVeBeenDrinkin' macrumors 65816

    iVeBeenDrinkin'

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    Oct 17, 2008
    #22
    My MBP was totaled but, the movie continued to play the whole way down.
     
  23. LemmycautioN macrumors member

    Joined:
    Sep 29, 2008
    Location:
    Seattle
    #23
    That is most likely the sudden motion sensor that grabs your HDD's actuator arm so that the disk doesn't get gouged. This is what causes the stutter in data read. If you want to turn it off this would solve the problem - if you consider it to be a problem - but if you drop it too fast or tap it too hard you will hurt your disk.

    open up a terminal window
    type: sudo pmset -g
    in the second line, across from the sms (sudden motion sensor) you'll see a 1, this means that it's on.
    now type: sudo pmset -a sms 0
    type the first command again to see if it's worked, the 1 across from the sms should now be a 0. Now that the sms is off your data read won't study, but as I mentioned early you could hurt your drive since the sudden motion sensor exists to protect the drive.

    To turn the sms back on run the same command but replace the 0 with a 1. sudo pmset -a sms 1
    You can check to see if it's on or off by using the sudo pmset -g


    ps. also only do this if you're running 10.4 or 10.5, the commands for earlier os x releases is a little different I think
     
  24. Luftwaffles macrumors regular

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    Nov 25, 2008
    Location:
    Kansas City, MO
    #24
    As others have stated, your sudden motion sensor is probably tripping and locking the drive mechanism for safety reasons.

    That said, I think for the sake of the scientific method the OP should post the specs of the machine in question, so people with *similar* machines can see if theirs suffer the same symptoms. A systematic and structured approach is beneficial to determining the exact cause.
     
  25. GGJstudios macrumors Westmere

    GGJstudios

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    May 16, 2008
    #25

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