Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.csd.uwm.edu!dogie.macc.wisc.edu!uwvax!astroatc!brown
From: brown@astroatc.UUCP (Vidiot)
Newsgroups: comp.sys.ibm.pc
Subject: Re: HELP - Hard Disk Lost.
Message-ID: <2663@astroatc.UUCP>
Date: 22 Aug 89 20:36:19 GMT
References: <1989Aug22.110751.29481@jarvis.csri.toronto.edu>
Reply-To: brown@astroatc.UUCP (Vidiot)
Organization: Vidiot's Hangout
Lines: 59

In article <1989Aug22.110751.29481@jarvis.csri.toronto.edu> laredo@csri.toronto.edu (Jim Alain Laredo) writes:
<Hello there,
<    My friend's PC doesn't recognize the hard disk anymore, any command
<like C:, format C:,etc, would give the error "no such disk" or something
<similar. Fdisk says "no fixed disk present". 
< 
<     What else can we do before giving up and attributing the problem
<to the hardware. And if it is the hardware, where would you think
<the problem is?

I had someone recently call me up to come over and find out why their XT
didn't see the hard disk anymore.  Since they knew I worked on this stuff,
I went over to do the normal checks.  So, here are some things you should
be to find out why there is a problem:

1) Open up the unit and check all hard disk connections.  Make sure that
   two connectors (or one depending on the system) are seated properly on
   both the controller card and on the hard drive itself.

2) Most importantly, you need to find out if the drive is spinning.  Too many
   times a drive will just plain freeze up.  This is what happened to the one
   that I went to go check out.  Take out the drive and reach in there with
   some kind of tool and try to spin the flywheel.  By spin I mean to just
   turn it.  Don't try and make it go real fast.  This idea is to "unstick"
   it.  Hook the drive back up to the PC (if you disconnected it), without
   putting it back in place.  The idea is to look at the spindle after the
   power is turned back on the physically see if it is spinning.  If it does
   indeed start spinning, don't go twisting the unit around alot, as the
   gyro forces may cause some problems.  See if the PC "sees" the drive now.

After these two major checks it still doesn't work, you either have a drive
problem or a controller problem.  Keep in mind that you just can't go and
grab a friend's controller to try out.  Even though the connectors may fit,
unless it uses the same disk writing pattern, the controller can't read the
info on the drive.  The controllers normally should be by the same manufacturer.
For instance, an Omti controller won't work with Western Digital, and vice-
versa.

Sorry if this isn't much, but out of all the PCs that I have worked on, the
checks above will solve most of them.  The only time it hasn't is when we
know for sure that the drive has crashed.  How, because it normally makes
a God-awful noise.  In this case, we take out the old drive, open it up
and do a postmortem.  I have collected a few scratched platters this way.

If everything appears to be ok, as a last resort you may want to try to do
low-level format.  You will have to find the instructions for the hard drive/
controller to be able to do this.  You can also try running debug, from a
floppy disk, and enter the debug command:  g c800:5
Not all controllers all start at c800:5, but will be in the general area.
If you can't get the low-level format to work, you really do have a hard
disk or controller problem.  It will then be time to see your dealer.

For everyone else, keeps these checks in mind.  They may come in handy
some day.  If someone else has some other suggestions, please add them.
-- 
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