Bryan,

In your hard drive is (in simple terms) a spinning disk impregnated with
magnetic media where the data is stored.  The data is retrieved via a
read/write head that is positioned in response to commands from the CPU.
The disk spins very fast; typically 4000 - 8000 RPM.  This high speed
allows the read/write head on your hard drive to "fly" over the spinning
disk on a cushion of air.

As you know, air density decreases with altitude.  At some point the
density decreases such that the air cushion supporting the read/write head
is insufficient allowing the head to contact the disk.  As you can
imagine, at those speeds the likelihood of physical damage to both the
disk and head is very high.  BTW, this is where the term "hard drive
crash" comes from; the head "crashes" into the disk.

For most crashes, even if you don't break anything severely enough to
cause an immediate failure you'll almost certainly have bits and pieces of
metal bouncing around inside the hard drive's case.  Enough damage (from
either the initial crash, or from the metal bits rattling around) and the
disk is trash.

In your case I suspect you damaged an area on the disk containing data
needed to boot the system, but not the head.  By reformatting and
reloading all the data you were able to recover.  I wouldn't be surprised
if you have intermittent problems with this hard drive in the future (due
to the debris inside the case), especially if the system is moved
frequently.


Mark & Lisa Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com



Posted for <bjburr@mwheli.com>:

  Matt,

  Why does the hard drive die.