18 Apr 2004, 11:42, TOM WALKER (1:123/140), wrote to MIKE ROSS:

Hi TOM.

 ->>  DD> I disagree. Some of the PCs we have at work have the drive 
 ->>  DD> mounted circuit side up.
 
 ->> I am surprised because upside down is the most common interdiction 
 ->> in manufacturer's warnings. These usually read mounting on either 
 ->> side is ok except upside down. Do you know why upside down is 
 ->> warned against?
 ->>  Mike

 TW>  I suspect Bearing Design is the limitation on orientation.

I doubt that.  The bearings are pre-loaded, so any orientation will still
be less than the tension of the pre-load.  

My 'best guess' would be the location of the filter inside the housing
which is _supposed_ to trap any particles that happen to get loose inside. 

Drives with a domed cover (are there still any like that?) would have the
filter BELOW the dome (and therefore BELOW the platters), and probably
shouldn't be run upside down.  Drives with a flat cover have the filter on
the side wall at a tangent to the platters and probably would make no
difference which way they were mounted.

     Good luck...  M.

--- Msged/386 TE 06 (pre)