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Hard drive repair (longish)

Discussion in 'Electronic Repair' started by PlainBill, Mar 25, 2005.

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  1. James Sweet

    James Sweet Guest

    Absolutely *do NOT* try this, at best you'll render the drive completely
  2. Asimov

    Asimov Guest

    "Dan" bravely wrote to "All" (25 Mar 05 09:33:04)
    --- on the heady topic of "Re: Hard drive repair (longish)"

    Da> From: Dan <>
    Da> Xref: aeinews

    Da> I'm sure there's some reason this is a stupid idea, but what if he
    Da> were to remove the disks from the old drive & carefully insert them
    Da> into a working drive? Maybe he could pick up a used example of the
    Da> one that has failed at a local used pc place & give this a try. I've
    Da> always supposed that something along these lines must be what done by
    Da> those places who obtain data from drives which have been in fires, run
    Da> over, etc., no?

    No, he could never align the radial position of the disks properly again.
    What those data recovery places do is to install their own control
    circuitry, motor drive, and heads onto the existing platters without
    disturbing their alignment. Their control heads can separately
    microstep between tracks to get the most reliable pickup.

    One trick nobody here mentioned is to put the failing drive into the
    freezer for an hour or so, then start it up cold. Apparently this can
    sometimes give one last chance at making a backup.


    .... Isn't Fourier and it's applications a bitch!
  3. Franc Zabkar

    Franc Zabkar Guest

    I used to service the old Control Data BK7 series disc drives. These
    had removable disc packs with 10 platters. An undetected overnight
    head crash would leave you with a drive full of metal debris and 20
    disintegrated heads. In those days the flying height of a head was
    about .0001", so the thickness of a fingerprint would have been enough
    to cause head-disc interference, at least according to CDC's tech
    notes. I've also seen a Seagate tech note that likened hard disc
    technology to a Jumbo jet flying at supersonic speed 1m above the
    ground, counting the blades of grass as they passed underneath.

    - Franc Zabkar
  4. NSM

    NSM Guest

    You could practice first by performing your own vasectomy, and then
    reversing it. After that you might like to try hard drive servicing without
    a clean room.

  5. philo

    philo Guest

    try slaving the drive to a a machine with an existing XP or NT-based OS
    and see if you can read the data
  6. PlainBill

    PlainBill Guest


    I've already tried setting the drive size manually without success.
    Part of the problem lies with the way LBA-48 seems to work. The drive
    parameters (C - H - S) are set to the maximum values (65,535 - 16 -
    255) and then the drive is apparently queried by the BIOS and reports
    the full capacity. One of my systems with a bios that supports LBA-48
    does not allow me to set parameters manually, the other still errors

    On the other hand, your idea of using the capacit limit jumper is
    something I never even thought of. I'll be giving it a try and
    reporting success or failure.

    If all else fails, I've got a few old expansion cards here. I've
    decided that I will give myself some practice removing and
    reinstalling SMT ICs on a scrap board before trying the real thing.

    Thanks for the advice.

  7. PlainBill

    PlainBill Guest

    Not a bad analogy. I also like the one: A hard drive head is a
    little airplane flying around above your data, looking for a place to

  8. PlainBill

    PlainBill Guest

    I could give it a try before trying anything potentially destructive,
    but I'm not optomistic. The new drive (and the old hda with the new
    electronics board) spins up as soon as power is applied. The old
    drive, (and the new hda with the old electronics board) won't spin up
    under any circumstances.

  9. PlainBill

    PlainBill Guest

    This has been reported to work on drives with unreadable sectors. In
    this case, it's a dead electronics board. Still, it's worth a shot if
    the board has a crack which will close if cooled down.

  10. PlainBill

    PlainBill Guest

    Mike, let's see if we can get on the same page here. I have a drive
    with a bad electronics board - won't spin the drive motor. On that
    board is a memory device which contains information for the bad

    I have a second drive with a good electronics board, and a memory
    device which contains information for the good drive. If I move the
    good electronics board to the bad drive, the bad drive now spins up,
    but is not useable - presumably because the memory device on the good
    board contains the wrong information.

    One possible option is to move the memory device from the bad board to
    the good board. That way IN THEORY the good board now contains the
    information for the 'bad' hda. I see two problems with this. First
    of all, the soldering is at the limit of my ability. Second of all,
    does the memory device contain information related to the board

    Alternatively, if it were possible to read and save the information
    from each each device, then write it back, I could avoid soldering.

  11. Dan

    Dan Guest

    What a clever idea. Unfortunately, I had mine done years ago, so I'll
    need another subject. I've got my rusty tin snips & oven mits; drop
    your pants, wise guy.

    So how DO data recover services work their magic on disabled/damaged hdd's?

  12. philo

    philo Guest

    but you originally said that the old drive
    with the new board on it DOES spin up...
    if that is so...then even if seen incorrectly in the bios...
    if you slave it to an existing OS...the data should still be readable
  13. James Sweet

    James Sweet Guest

    I would start by getting a datasheet for the memory device from the
    manufacture's website and see what's required to program it. If it's not
    socketed though I'd be very hesitant to muck with the new drive, I still
    think it'd be a better idea to find someone who can replace the motor driver
    chip though.
  14. James Sweet

    James Sweet Guest

    I've got a couple dead DiamondMax drives right here, they both go click
    click click and won't read.
  15. James Sweet

    James Sweet Guest


    I opened a 20MB (yes megabyte) drive once simply because it was 12 years old
    and of zero real value and it continued to work for quite some time though
    gradually developed some bad sectors. I suspect newer larger capacity drives
    are a LOT more sensitive though, this thing used an actual stepper motor to
    position the head assembly. It was fascinating to watch it read and write
    though, I still have it on display on my bookshelf though a while back I
    rotated the platter and it ripped one of the heads off the arm, oops.
  16. James Sweet

    James Sweet Guest

    Of course the "ground" is also quite a lot more level than any field of
    grass you'd find on earth but it's interesting none the less.
  17. James Sweet

    James Sweet Guest

    Forgot about that one, I've had some luck with it, though in this case it's
    highly unlikely since we know the motor controller is fried. The freezer
    trick mostly just works with drives that spin up but can't read reliably.
  18. James Sweet

    James Sweet Guest

    They do something conceptually similar, but they put the platters in their
    own special (and *very* expensive equipment) in a clean room environment.
    The read/write heads they use can be manually controlled to read the data, a
    hard drive's onboard controller and mechanics are just not capable of this.
  19. James Sweet

    James Sweet Guest

    Remove with a heat gun (mask surrounding components with something). To
    reinstall, put some liquid flux on the pads, and dip the chip pins in it as
    well. Put a small dab of hot glue or double sided tape on the bottom of the
    chip, carefully align it and stick it in place, then form a ball of solder
    on the end of the iron and carefully drag it across the pins while keeping
    the ball fed with fresh solder. With some luck the flux wil keep the solder
    from bridging and the chip will neatly be soldered down. I always thought
    it'd be super hard to solder this stuff but it turned out it was easier than
    I thought.
  20. Asimov

    Asimov Guest

    "Sam Goldwasser" bravely wrote to "All" (25 Mar 05 21:57:18)
    --- on the heady topic of "Re: Hard drive repair (longish)"

    SG> From: Sam Goldwasser <>
    SG> Xref: aeinews

    SG> Yes, but in a relatively clean office environment, they won't die
    SG> instantly.

    You can have a cleanroom environment by installing a hepa filter with
    a boxer fan blowing air into a box large enough to work in. The
    positive air flow keeps any external dust from falling in the box.
    Be sure to run the fan for a while and vacuum the interior very well.
    It is rudimentary but better than nothing. Don't forget the hair net!


    .... Techs would rather pee on an electric fence for the light show
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