I'm not sure but it seems like you've tried to connect it in USB again, with the Seagate Expansion enclosure, as opposed to directly connecting it in SATA (or if not possible, at least through a
standard external enclosure, not the native Seagate one – there may be something corrupted at that level, at least you need to rule that out).
To others : what happens when a HDD is used through an enclosure having that special kind of formatting I mentioned, automatically translating 512 bytes sectors into 4KB sectors (visible to the host machine), and the controler somehow gets corrupted ? Would it be consistent with what is observed here ? Is it possible to fix through software-only means, by manually correcting the partition table, or MBR, or something ? I myself bought a used 3TB ST3000DM001 (bad, I know – I only got movies on it) in a Seagate Expansion enclosure, I don't quite remember the specifics, but when I opened it and connected the drive directly in SATA, the partition was no longer recognized, I had to re-format it in SATA to be able to use it (it was empty at that point). Could it be something similar ? I could make some tests if that can
really help.
As it's been said earlier, you should try to connect it through SATA with a “reasonably current” desktop machine (less than 5 years to be on the safe side), running with an operating system which is natively compatible with 3TB+ storage units (Windows Vista at least, Windows 7 preferable, any current Linux distribution – the one I now use for recovery purposes is
the one custom-made by the author of HDDSuperClone, based on Lubuntu, containing that tool plus ddrescue 1.22, otherwise stripped-to-the-bone but you get those two excellent tools in one convenient and ready to use package, without unnecessary clutter like a gazillion different screensavers that I saw in Knoppix...).
Earlier you showed a screenshot where the actual name of the HDD appeared (ST3000DM001) : that was “promising” (even if that's still far from a victory, there can be many intricacies, some of which would be puzzling to me...). If you manage to get it recognized under Windows, but still get a 0 byte capacity and no drive letter, first check the SMART parameters (CrystalDiskInfo, HDTune...), then if all is fine, open the whole drive with an hexadecimal editor (WinHex if you can, or HxD which is free) and post a screenshot of what you see. If you get that far, you can then clone it or image it to another 3TB, preferably 4TB HDD (you can do that with WinHex or HxD
if the drive is stable and doesn't have bad sectors or other SMART issues), and
then either try to fix the HDD “
in situ” (having a backup if it fails) or analyze the clone/image with good recovery softwares (R-Studio is an efficient and versatile commercial one, reasonably priced ; TestDisk is a free but powerful tool which can fix partitions in certain cases, while its companion program Photorec can “carve” files in “raw” mode, as a last resort, when no file system information could be retrieved). DO NOT run chkdsk, or accept to “fix” the drive, if prompted to do so, at least not unless you've made a clone/copy of the drive in its current state. (But it's possible that I've missed some key details which clearly indicate that you won't get that far, as other undoubtedly competent people have said, I don't want to give you false hope...)
Quote:
What if the zero track is bad? Then a dead hard drive?
From what I could gather, if
only the “zero track” or “System area” is damaged, then a “live PCB swap” could be attempted, using a functional unit with the exact same reference – BUT I've been warned against that very procedure in
another thread, so let's pretend that I didn't write this !
Also, if the SA was damaged, the HDD would probably be clicking, apparently you don't hear anything abnormal so I would say that it's unlikely to be the cause here.