The
most common problems originate from corruption of the master boot record, FAT,
or directory. Those are soft problems which can usually be taken care of with a
combination of tools like Fdisk /mbr to refresh the master boot record followed
by a reboot and Norton disk doctor or Spinneret.
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 onboard 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.
a.
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.
b.
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 your 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.
c.
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.
d.
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.
If
the info is all that important to you, I would seek some professional and
experience technician in your locality who makes his living from servicing and
building computer systems ... not just selling them. If you have had much
experience salvaging information from bad hard drives, your likelihood of success
is low. In the case of soft corruption, all utilities have their
eccentricities. Often times, Norton Disk Doctor will go too far (if you let
it). It's wise to just let those utilities small steps and then have a look at
the drive and see if you can copy it off. Norton will go so far as to rename directories
and files, and even delete them or break them up into fragments which are useless.
