Franc Zabkar wrote:
On Thu, 13 May 2010 11:40:28 -0700, "David Farber"
put finger to keyboard and composed:

I use my generic, home made, pc to test and analyze client's hard
drives. The motherboard in my pc is an ECS NFORCE3. It's never given
me any problems. When I hooked up the test drive in question (lots
of knocking noises) on the second IDE channel, the pc booted, the pc
speaker beeped once (normal for this pc), but it just froze after
that. I rebooted and tried to go into the setup menu but that didn't
work either. I gave up on the test and removed the drive I was
checking. But now, the same problem occurs. The pc powers up,
speaker beeps, and it freezes there. If I press "delete" to enter
setup, it just hangs without going into setup. If I remember
correctly, immediately after removing the test drive, I was able to
get to the bios menu but it said no drive was installed. I used the
internal clear CMOS jumper to reset the bios but the outcome was the
same. Now, I am not even able to get that far. If I put in any other
drive, I am able to access the bios menu and the drive is recognized
correctly. I was not having any problems with the drive before
adding the test drive on the secondary IDE channel. I can feel the
motor humming when the machine is powered up. I've tried switching
between "cable select" and "master=on, slave =off," that didn't
help. There are no clicking or foreign noises. I was hoping to
purchase a used drive of the same model and swap out the controller
boards. My question is, how close of a match do these boards have to
be? So far I have found the same drive model number and firmware
code, but a different HDA p/n. Anyone have any luck doing a swap
like this? Is there some identifying data on the hard drive platters
themselves that would cause the drive to "disappear" like this? I
did try the drive in another pc. It gave a similar error, "Drive not
detected," and asked if I wanted to bypass the detection process.

Thanks for your reply.


If the drive spins up but is not detected, then the fault is most
likely inside the HDA (head/disc assembly). However, I have seen cases
where a bad IDE cable produces the same symptom. That said, if you
decide to replace the circuit board, be prepared to transplant the
serial EEPROM (flash) chip from patient to donor. On newer models this
chip stores unique drive specific calibration data.

See the following article for help in identifying the components.

HDD from inside Main parts:
http://hddscan.com/doc/HDD_from_inside.html

The following article explains why drives have "adaptive" data.

HDD from inside: Tracks and Zones. How hard it can be?
http://hddscan.com/doc/HDD_Tracks_and_Zones.html

Essentially the reason is that no two heads are physically identical.
HD manufacturers try to fit as much data as possible onto each
platter. To do this, they take advantage of any head that performs
better than the average.

For example, some heads will have a better frequency response than
others, which means that you can cram more bits on each track. This
technique is called Variable Bits Per Inch (VBPI).

Giant magnetorestive (GMR) heads use a separate element for writing
and another for reading. The separation between these two components
varies from head to head. Once again manufacturers optimise data
density by implementing Variable Tracks Per Inch (VTPI).

Each HD therefore needs to be calibrated to account for VBPI and VTPI,
otherwise the drive doesn't know where to find the tracks, or the data
within the track. When a drive powers up, it needs to retrieve the
bulk of its firmware from a reserved area (System Area) on the
platters. If it can't read these data, then it clicks. This is what
usually happens after you swap a board without transferring the
calibration information.

- Franc Zabkar


Great info Franc. However I'm glad I didn't open the drive. That certainly
would have ruined it for good.

As it turns out, the drive suffered a "clipping" problem. See my post a few
messages after this one in response to Chris Oates.

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA