Data Recovery: its easy, just swap a board….

Auto Date March 24th

I read this advice the other day on a forum. A guy had a dead hard drive and the suggestion was to go on Ebay and buy a same model drive and swap the board. At one time that would work but those days are long gone.

It used to be that when a board failed that you could just buy another drive with the same firmware and swap the board and maybe your drive would work.  The chances of this working on current drives is about zero. Modern drives are calibrated to extremely fine tolerances. The manufacturers are squeezing every last  bit of performance out of the hardware. One way they do this is by calibrating each head and drive and platter at the factory. You see not all heads read and write  with the same sensitivity. Platters do not have the same magnetic coercivity evenly everywhere. So the manufactures build the drives and then they run a bunch of tests  to determine how much voltage each head needs for each part of the platter to write and read. All this information is stored in tables and saved in the drives firmware.  These values are called ‘adaptives’ and are unique to each drive – so swapping a board won’t work. In order to swap a board you have to reprogram it or fix it. This requires special expensive equipment and knowledge.

Oh… and the other problem is finding a board with a matching firmware revision. Manufacturers change their firmware constantly. It even differs by country and head amplifier chip.

hmmm... fried brain.... Marvel chip on a Western Digital

hmmm... fried brain.... Marvel chip on a Western Digital


This entry was posted on Wednesday, March 24th, 2010 at 1:48 pmand is filed under Products. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

  • http://www.aitsavemyfiles.com/ Chris – Armor-IT

    Hi,

    I disagree with the “0″ chance but agree in general. There are very few chances of simply swapping boards. However, even with performance stats as they are, one can often either perform a live swap and retrieve a great deal of data or if you're gutsy enough attempt a palette swap which has similar issues but really guarantees you only get one shot.

    Frankly, there are enough companies now with pick and place machines that as long as the firmware is intact, you can usually get a firmware chip moved from the dead board to a donor PCB board for a couple hundred bucks. This effectively “clones” the original board. Still with any recovery method there are risks.

    Like I said, in general I agree but there are alternatives, I wouldn't be so quick to dismiss the mentioned article, unless of course the drive in question was a Seagate 7200 series in which case a full firmware transplant will definitely be required.

  • Bob

    does that meen that the platters cannot be taken out of the hd and put into a cd/dvd/ player to recover the data on it.

  • koreyb

    No, different technology. Hard drives use magnetization of platters optical media (like CDs and DVDs) uses pits and lands read by lasers.

  • http://www.aitsavemyfiles.com Chris

    Hi Bob,

    Transplanting platters can be done in most cases but it's extremely delicate and requires specialty tools and can only be safely done in a clean room. This is why some types of data recovery are so terribly expensive.

  • http://www.rushpcb.co.uk/ PCB Manufacture

    This requires special expensive equipment and knowledge.Optical media (like CDs and DVDs) uses pits and lands read by lasers. This is why some types of data recovery are so terribly expensive.

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