The most common hardware problems are a bad controller, a bad
drive motor, or a bad head mechanism.
1. Can the BIOS see and identify the hard drive correctly? If
it can’t, then the hard drives on board controller is bad.
2. Does the drive spin and maintain a constant velocity? If it
does, that’s good news. The motor is functioning.
3. If the drive surges and dies, the most likely cause is a
bad controller (assuming the drive is cool). A gate allowing
the current to drive the motor may not be staying open. The
drive needs a new controller.
4. Do you hear a lot of head clatter when the machine is
turned on and initialized (but before the system attempts to
access the hard drive). Head clatter would indicate that the
spindle bearings are sloppy or worn badly. Maybe even lose and
flopping around inside.
5. There is always the possibility that the controller you are
using in the machine has gone south.
1. If the drive spins, try booting to the A> prompt, run Fdisk
and check to see if Fdisk can see a partition on the hard
drive. If Fdisk can see the partition, that means that it can
access the drive and that the controller electronics are
functioning correctly. If there is no head clatter, it may be
just a matter of disk corruption which commonly occurs when a
surge hits you machine and overwhelms the power supply voltage
regulator. It commonly over whelms the system electronics
allowing an EM pulse to wipe out the master boot record, file
allocations table, and primary directory. Fdisk can fix the
master boot record and Norton Disk Doctor can restore the FAT
and Directory from the secondaries.
2. The drive spins but Fdisk can’t see it. Try the drive in
another system and repeat the test to confirm that Fdisk can’t
read through the drives onboard controller. If it sees it in
another system, then your machines hard drive interface is
bad. You can try an upgraded or replacement controller card
like a Promise or CMD Technologies (there are others) in you
machine after disabling the integrated controller in the BIOS,
but if the integrated controller went south, it may just be
symptomatic of further failures and you’d be wise to replace
the motherboard. Trying the drive in another machine also
eliminates the variable that your machines 12 volt power
output being bad
3. If you get head clatter but a constant velocity on the
drive motor (no surging), you might try sticking the hard
drive in the freezer for about 12 hours. This is an old trick
from back in the days of the MFM/ESDI driver era. This can
cause the drive components to shrink enough to make the track
marker align with the tracks. We don’t see that kind of
platter spindle wear much anymore, but back in the old days,
the balancing and bearings weren’t as good. Still, under the
right circumstances, it might help. It would depend on how old
the drive is and how many hours of wear have occurred. You
have to be quick to get your info off the drive when it works.
Back then, the drives were much smaller, so there wasn’t so
much to copy. So, go after the important data first.
4. The drive doesn’t spin. Either the onboard controller is
bad or the motor is bad (assuming you did try the drive in
another machine). It’s time to hit the net and local
independent shops to see if you can locate another drive of
the same make and model that’s good. Since the drive is
probably an older drive and no longer in distribution, your
best bet is to find an identical used drive. If you know
someone with the same make and model, you might be wise to try
and persuade them to sell you their drive with an offer of
providing them with a free upgraded drive. If you can locate
an identical drive, start with the controller replacement …
this is the simplest and least invasive. If swapping the
controller doesn’t produce the desire result, you can tear
into the drive and swap the motors. While you have both drive
opened up to accomplish this, scrutinize the platters, heads
and armatures. You might even hook the drive up and power it
from a system with both drives attached. This way, you could
see anything that deviates between the actions of both drives
when they are initialized. Swapping patters is unlikely to
produce any positive result. They are a balanced system like
the tires on your car and I suspect that the balance will be
different for each drive as will other variables.