SCSI Disks

[Mike Bilow]

A James Lewis wrote in a message to Mike Bilow:

 AJL> I dont know of any problems specifically with those drives,
 AJL> however micr[ao]polis (IMHO) went out of business for a
 AJL> reason, I have had so many of their drives fail that I would
 AJL> never buy one again.... However I understand that there was
 AJL> a particular period where their drives were very bad and
 AJL> that drive sounds older than that.... Newer ones should have
 AJL> been better too..... Anyone else had a 4221 fail... 

 AJL> Mine was so bad that under examination the platters could be
 AJL> moved in directions other than round!!!!!

I suppose there's no harm in explaining this, given that Micropolis is no
longer trying to sell drives.  What I was told from an authoritative source was
that one of Micropolis' contractors falsified QA test results on spindle
bearings, and these were used in some of the 3.5-inch drives, including the
3243 and 4221.  The out-of-tolerance spindle bearings would cause the drives to
run hot, which increased spindle bearing wear in a vicious circle.

Newer production runs of the 3.5-inch drives used good spindle bearings and did
not fail as readily.  Since Micropolis was leading the industry with a
five-year warranty, they certainly would have had no incentive to try and cut
corners on their quality.

None of these problems ever affected the 5.25-inch drives such as the 1991.  In
fact, to this day, we have never had a 5.25-inch Micropolis fail.

The secret to longevity in all Micropolis drives is to make sure there is a
huge supply of cooling capacity.  Mounting kits are available which allow a
3.5-inch hard drive to be placed in a 5.25-inch bay, with fans pointed directly
onto the drive.  An example would be the US$25 Model AS-12 from Jinco
("http://www.jinco.com").  There are also products such as the FanCard which
can be inserted into a full-length ISA slot to provide overcooling; these are
available from Dalco ("http://www.dalco.com") and other sources.
 
-- Mike