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From: silverio@brahms.berkeley.edu (C J Silverio)
Newsgroups: comp.sys.mac,comp.sys.mac.hardware
Subject: Drive Noises and such...
Message-ID: <1989Nov21.012836.1292@agate.berkeley.edu>
Date: 21 Nov 89 01:28:36 GMT
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Reply-To: silverio@brahms.berkeley.edu.UUCP (C J Silverio)
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Julian Vrieslander writes:
  I do notice that the drive will occasionally exercize its swing arm when
  there is no read/write going on.  Every few minutes there is a very brief
  sound, as if the arm makes one stroke and stops (I have not timed it).

I've had a lot of experience with hard disk drives, so I know this
noise well. It is often called "thermal realignment" and is NORMAL for
many brands of drive. Because of the precise tolerances on tracks, the
drive will seek a few tracks every few minutes, to recalibrate its
servo mechanisms. Reason: as the drive warms up, the distance between
the tracks increases.

Really folks, don't be so paranoid.