It used to be that when a board failed you could just buy another drive with the same firmware and swap the board and your drive would *possibly* work. Whole side businesses have sprung up marketing boards on eBay and Craigslist. The chances of this working on current drives is about zero.

Modern drives are calibrated to extremely fine tolerances. The manufacturers do this to squeeze every last bit of performance out of the hardware.

One way they do this is by calibrating each head, 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 across the platter.  Because of this 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 drive’s firmware.
These values are called ‘adaptives’ and are unique to each drive – so swapping a board wont work.

In order to swap a board you have to reprogram it, fix it or swap the chips. This requires special expensive equipment and knowledge to properly recover the data.

This entry was posted on Tuesday, May 18th, 2010 at 7:04 pmand is filed under Guide. 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.