From: bob@kc2wz.bubble.org (Bob Billson)
Newsgroups: sci.electronics
Subject: HELP: spinup problem with Micropolis 1325D hard disk
Summary: why doesn't my 1325 like to spinup?
Keywords: help hard disk
Date: 5 Nov 92 16:57:46 GMT
Organization: Color Computer 3: Tandy's 'game' machine

Hi net.world, I need your help!

I have a Micropolis 1325D hard disk (MFM, 71 meg).  Back in August when we were
having our usual hot summer days, the 1325 start acting "weird".  The
temperature got up to 95 degrees (F) in the room where I keep the computer.  Up
to this point the 1325 has be very reliable.

On the first day of the hot spell I turned the computer on, the hard drive
began to spinup; just as it reached the point where the heads would unpark, it
started spinning down...uh oh!

After killing the power, I checked the hard drive (it is external) and cable
connections.  Everything appeared okay, power supply was working properly.
Try again...same symptoms.  After about 30 seconds the hard drive started to
spinup and again just before the heads unparked, it slowed down.  This cycle
repeated twice before the hard drive stopped trying.  Hmmm... The drive was
was quite warm though NOT hot enough to indicate some component was on the edge
of failing.  Hmmm....

I then recalled similar symptoms the previous summer during a hot spell. I 
solved it by removing the cover and blowing a muffin fan on the drive.  I tried
this trick again and after a half hour the drive worked.  It continued working
without any problems.  Because the temperature in the room was still very
warm, I left the fan on the hard drive.

I turned the computer off that evening.  The next day, which was hotter, the
problem turned up again.  This time the fan didn't help...uh oh.  I needed to
get at some info on the disk--what to do?  Out of desperation I disconnected 
the hard drive, wrapped in a plastic bag (to prevent condensation on the drive 
itself) and put the package in my refrigerator.  I figured this would cool
down the hard drive sufficiently.  After 10 minutes, I hooked everything
back up and it worked.  The next day the hot weather broke and the system once
being normal.

A few weeks ago, the symptoms returned.  This time cause is more mysterious.
The room is at 70 degrees (F), so that is not the problem.  Letting the drive
"cool off" overnight does NOT solve the problem.   Putting the drive in the
refrigerator gets it working again.  I figure there must be a component
somewhere which is getting ready to fail.  Spraying some component cooler
around the boards has not isolated the defective component.

Does anyone have any suggestions what the problem is?  Right now I leave the
hard drive on all the time.  So long as I do this, I have no problems.  I 
would like to be able to turn my hard drive off occasionally. :-)  So long as
problem is not inside with the platters, I am reasonably sure I can fix it...if
I knew where to look.  Suggestions?

Thanks for the help.

      Bob
-- 
  Bob Billson, KC2WZ                          | internet: bob@kc2wz.bubble.org
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  "Professional ear piercing--while you wait!"  --sign in local jewelry store
Newsgroups: sci.electronics