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I feel that my question is probably too wide, I'm willing to focus my question more if needed and possible. Please comment.

I have a hard-drive (2.5" Toshiba) which was installed in a notebook. The notebook fell from a table (on the side) while running. Since then the disk makes the click-of-death-sound and is no longer recognized either by the system or when attached to a SATA-USB-adapter on another PC.

In the past, for another hard-disk with the same symptoms, I did/tried a transfer of the hard-drive-heads from a working disk to the non-working one. I was unable to make the broken disk work again - the click-of-death remained. The data was lost.

At that time I only transplanted the hard-drive heads. I was as careful as possible. I saw that the heads of the broken drive were visibly damaged. The donor-drive was the same model, but not the same creation date.

When done, I let the disk run while being semi-open. I saw what created the click-of-death: it's the heads running over the whole disk and then returning abruptly onto their parking position - this is when it is clicking. The controller instructed the drive to do it again and again. It was surely looking for some "known-data".

Now, for my current broken disk, I have a working model of the same revision and date ready to be a donor. But I'm unsure - this time I really would love to get back the data.

What causes the controller to scan the disks again and again? What is it looking for?

Why does replacing a physically damaged head not help?

Is there some kind of calibration stored on the PCB which is adapted for the heads?

Transferring the heads was relatively easy. Was it too easy? Did I probably break something, even though I was really careful?

psmears
  • 549
Patrick B.
  • 3,128

1 Answers1

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The "click of death", in hard drives, isn't a single specific problem. It's a symptom which is often displayed by a failed hard drive -- the "click" is the sound of the drive resetting the heads after it fails to read data from the disk. This can be for any number of reasons: it can happen if the heads or the amplifier circuitry on the arm are damaged, if the receiver on the logic board is not working properly, if the disk is missing calibration data, if the drive is not spinning at the right speed, if the drive is failing to read its firmware from the disk... it can really be the result of almost any fault.

Do not try to transplant heads between drives. This was sometimes possible in the past, but tolerances in modern hardware have shrunk to the point that it's no longer possible to remove and replace the heads by hand. You will damage the heads, and the surface of the disk, if you attempt to do so.

If you believe that the mechanical components of your hard drive have been damaged, and you want to recover the drive's contents, contact a professional drive recovery service. Anything you do will only make the damage worse, and may render it unrecoverable even by a professional.