Spontaneous Corruption

Discussion in 'Macintosh Computers' started by Nermal, Mar 6, 2005.

  1. Moderator

    Nermal

    Staff Member

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    Whakatane, New Zealand
    #1
    I've been having problems recently where files seem to become damaged for no apparent reason. For example, I had a video file which played fine, then tried it again a couple of days later and found that some of the frames were damaged. I've also had BitTorrent downloads fail due to detected corruption, the BT client asks me to ensure that no other apps are accessing the file at the same time. In addition, apps sometimes quit without warning (Word quit itself before, when I wasn't even touching the computer).

    I've tried the usual things like repairing permissions, and I have a suspicion that it's bad memory, but Apple Hardware Test didn't find anything wrong with it (it's Samsung memory, the same stuff Apple uses).

    Any suggestions? I might remove some memory and see whether it helps.
     
  2. macrumors 68000

    Joined:
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    NH
    #2
    Are you using 10.3.8?

    Are your files on an external hard drive?

    If the answer is yes to both, then, I'd say you are in good company...

    I had to re-install several Apps after after updating to 10.3.8. It really screwed up a lot of things for me. The apps run fine now that I've reinstalled them.
     
  3. thread starter Moderator

    Nermal

    Staff Member

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    #3
    I do have 10.3.8, but I don't have an external drive. I've removed one stick of memory and haven't had any problems yet, but of course just a few minutes without problems doesn't really prove anything. If it's still working fine after a few days then I'll put the memory back in and see whether the problems return.
     
  4. macrumors 68020

    daveL

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    Location:
    Montana
    #4
    Intermittent memory errors sounds like a reasonable guess. Could be something with your disk drive, too. Have you checked the disk's S.M.A.R.T. status in Disk Utility?
     
  5. thread starter Moderator

    Nermal

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    #5
    Disk Utility says it's Verified, so it should be OK. It's not an old drive (had it since mid-2004) so it'd surprise me if there's something wrong with it.
     
  6. macrumors 68030

    superbovine

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    Nov 7, 2003
    #6
    have you verified the file is ok on a different computer?
     
  7. thread starter Moderator

    Nermal

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    #7
    It's more than one file. A couple of different video files seemed to corrupt themselves (using different players), and I also had a network copy problem: I copied a large (600 MB) file from another computer onto this one. The resulting file was damaged. I copied it again, and it was damaged in a different place. I then removed a memory module and attempted the copy a third time, and it worked flawlessly.

    I'm now pretty sure that it's the memory at fault. I've investigated a bit, the module I removed is the one closest to the VPU (Radeon 9800 Pro). I have a suspicion that the heat generated by the VPU is causing the memory to overheat, as it's quite warm. Does this sound like a possibility?
     
  8. macrumors 6502

    Joined:
    Dec 10, 2002
    Location:
    WA
    #8
    Are these files downloaded off of the internet?

    If so, you may be having problems with your internet provider. I had some corruption problems with .mac and verizon about a year ago. Any image I sent or retrieved from .mac. was corrupted. They did fix it.
     
  9. thread starter Moderator

    Nermal

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    #9
    I presume you're talking about the video files. No, they're not from the Internet. My connection seems to be fine.

    Still no problems since removing the memory. I'm almost positive that it was the cause of my problems.
     
  10. macrumors 68020

    daveL

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    #10
    Yes, it does. If you have a marginal piece of hardware, excess heat can definitely send it over the edge.
     
  11. macrumors 68000

    slipper

    Joined:
    Nov 19, 2003
    #11
    ohh.. by the name i assumed it was a post about enron or halliburton
     
  12. Moderator emeritus

    yellow

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    Location:
    Portland, OR
    #12
    Try using Memtest OS X to test your RAM. Let it run for a while (hour(s)). It's an excellent product that does a great job accurately testing the limits of your RAM.

    IMO, it's possible a hard drive problem if a static file is being spontaneously corrupted.
     
  13. thread starter Moderator

    Nermal

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    #13
    Thanks, I'll leave that running tonight and see what happens.
     
  14. thread starter Moderator

    Nermal

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    #14
    OK, I forgot to test the memory, but I did remember eventually. It failed. Time to read the warranty on my memory.

    Edit: Warranty only applies to manufacturing defects, so assuming that the heat of my VPU killed it, the warranty doesn't apply :(
     
  15. macrumors 68020

    daveL

    Joined:
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    Location:
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    #15
    But there's no way to know what caused the failure. Get it replaced. The memory vendor isn't going to second guess the cause, unless it looks like someone took a hammer to it or it's burned and crispy around the edges.
     
  16. thread starter Moderator

    Nermal

    Staff Member

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    #16
    Hmm, I just thought of something. If the memory is indeed being overheated, maybe I should test it again without the VPU right next to it :rolleyes:. It's possible that the memory itself is fine so long as it's cool enough. I'd hate to send memory overseas (I ordered online from the US) only to find that there's nothing wrong with it.

    Edit: A quick test didn't turn up any problems. I know that you really need to leave the test running overnight, but it was failing almost instantly before. I currently have the 'bad' memory in the slot furthest from the heat source, I'll use the system for a couple of days and see whether it behaves itself.
     

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