Opinions sought on a way to fix a failed IBM Deskstar HDD

Hello

My 100GB IBM Deskstar ("DeathStar") drive (type IC35L100 series ) packed up
a few days ago. It was being used in an IDE- USB enclosure and basically ,
XP failed to recognise
it as a drive. I tried it in the computer's BIOS which also fails to
recognise it.

Judging by the sound it makes, the heads are tracking across the platters OK
but failing to calibrate or locate track 0. Internet research suggests an
NVRAM failure ( the HDD BIOS may be corrupted).

Having found a potential donor 120GB Hitachi drive (Hit. took over IBM's HDD
business), I plan to get a known working controller PCB with a similar
Machine Level Code (MLC) revision, and substitute it for the board on my
failed drive. I aim to recover some/all data this way. Again, internet
research shows some success ... but only "some".

Questions then:

1) Does anyone know what the NVRAM or BIOS actually does on a HDD that might
change between revisions of the same HDD, or between generically similar
versions of the same HDD?

2) How likely do you think I might be in succeeding, whereby I use a similar
MLC coded PCB but not identical? A daft question I suppose in that the
changes per MLC release may be significant.

It's not a subject I am particularly familiar with so if someone has some
suggestions I'd be happy to learn. Unfortunately, a data recovery company
will charge many hundres of pounds so not viable in this case.

Thanks for any useful tips or experiences you can share; I don't know a fat
lot about the component-level functionality of how a hard drive works so I'm
keen to learn a little.

DDS

Duncan Di Saudelli <not@home.com> wrote
[color=blue]
> My 100GB IBM Deskstar ("DeathStar") drive (type IC35L100 series )
> packed up a few days ago. It was being used in an IDE- USB enclosure and basically , XP failed to recognise it as a
> drive. I tried it in the computer's BIOS which also fails to recognise it.[/color]
[color=blue]
> Judging by the sound it makes, the heads are tracking across the platters OK[/color]

Presumably you actually mean that the heads do move.
[color=blue]
> but failing to calibrate or locate track 0. Internet research suggests an NVRAM failure ( the HDD BIOS may be
> corrupted).[/color]

Its much more likely to be just another deathstar failure that produced a full class action suit.
[color=blue]
> Having found a potential donor 120GB Hitachi drive (Hit. took over
> IBM's HDD business), I plan to get a known working controller PCB
> with a similar Machine Level Code (MLC) revision, and substitute it
> for the board on my failed drive. I aim to recover some/all data this
> way. Again, internet research shows some success ... but only "some".[/color]
[color=blue]
> Questions then:[/color]
[color=blue]
> 1) Does anyone know what the NVRAM or BIOS actually does on a HDD that might change between revisions of the same HDD,
> or between generically similar versions of the same HDD?[/color]

Can be anything that changes between versions.
[color=blue]
> 2) How likely do you think I might be in succeeding, whereby I use a similar MLC coded PCB but not identical?[/color]

Depends on whether there was a substantial change between those.
[color=blue]
> A daft question I suppose in that the changes per MLC release may be significant.[/color]

Yep, and its impossible to predict how significant with a particular pair.
[color=blue]
> It's not a subject I am particularly familiar with so if someone has some suggestions I'd be happy to learn.
> Unfortunately, a data recovery company will charge many hundres of pounds so not viable in this case.[/color]

There are a few that dont charge as much as that.
[color=blue]
> Thanks for any useful tips or experiences you can share; I don't know a fat lot about the component-level
> functionality of how a hard drive works so I'm keen to learn a little.[/color]

The last thing you should be doing is learning on a drive where the data matters.