In misc.survivalism Cliff wrote:
On Tue, 06 Sep 2005 13:32:45 -0700, Jim Stewart
wrote:

I've taken apart dozens and as far as I can
see, they are all vented in some way or another.

Reminds me of GM headlamps ..... the last thing they
did was to install a hole to let the water in.
When it gets enough water sloshing about it will hit the
real bulb & *poof*.

But the drives are supposed to be sealed.

No, they arn't.
Sealing against 1-2PSI of varying air pressure (as you change location)
is really problematic.
If it fails, even slightly, then it may suck in debris, not to mention
the forces of some 30 pounds or so on each side of the drive distorting
it and making it not work.
All hard drives have breather holes of some sort, as that way they can
filter the air coming in, instead of attempting a hermetic seal.