February 22nd, 2018, 5:16
February 22nd, 2018, 11:58
February 22nd, 2018, 12:20
abolibibelot wrote: But here (and in Scott Moulton's talk) it's described as a quite straightforward operation which doesn't require any special material or software, and could indeed work if the failure comes from a scratch on the drive's system area – kinda contradictory informations.
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February 22nd, 2018, 13:49
February 22nd, 2018, 14:25
February 22nd, 2018, 16:18
Hot Swap would be pointless because you would have the translator loaded from the donor drive in the RAM so you wouldn't be able to properly retrieve data. You can do that to TEST only. If the heads still "click" and the drive doesn't read anything at all (you can't scan a single sector with victoria) and/or you can't read SA modules with something like a free DEMO of WDMarvel then most likely the head(s) are gone.
If i were to put a limit on drives that you can still open for some short time outside of a HEPA 100 clean room and still recover some of the data i would say 80 GB drives and only if you don't have a huge amount of dust particles on the air and if the dust particles are not going to get "stuck" to the platter like humidity and stuff that will be grudded to the platter. If it's just some particles of "dried" dust those will most likely "fly way" from the platter as soon as it starts to spin. If you live in a place that is very dry and have no humidity you will have more chances. But only with 3.5 drives that are 80 GB or smaller and also if they don't have special "problems" like Quantum drives or some older WD drives that will loose the head alignment if you unscrew the lid as it holds the head assembly as well.
February 22nd, 2018, 17:51
February 27th, 2018, 8:59
February 27th, 2018, 11:46
February 28th, 2018, 5:40
Repair process, best guess: Drive is opened in clean room, and actuator assembly and platters are removed.
New actuator assembly from suitable donor drive is installed, with the suspension assemblies of the heads for any surfaces deemed beyond recovery removed.
All critical system data is read from the drives most intact System Area, and pushed into drive RAM, modified to "hide" any missing heads to allow automatic initialization tests to pass while preserving zone table and translation mapping. This mapping is unique to every drive, and is generated during the drives assembly. It cannot be replaced with data from another drive without causing catastrophic data corruption. Once drive reports state "Ready", changes can be made to the drives RAM state to disable all of the drive self-repair functions which will hinder imaging. Imaging can then be attempted from the drives undamaged platter surfaces in accordance with the zone mapping.
And after that (assuming the imaging went reasonably well), the data has to be checked to see what (if any) of the original file structure remains, and repairs made where possible. Given that your drive has 2 platters, with all 4 sides in use (best guess, it is possible your drive is a "mule" unit, basically a cut down 1TB drive with 3 platters), and the zones (amount of data drive writes to one surface continuously before moving up the stack)are roughly 100MB, we can say that a single badly damaged surface will destroy any files over 300MB in size. If all surfaces are in reasonable good shape, then a very good recovery is certainly possible. But that possibility gets smaller with every click it makes.
So the next step, as Kuno-san noted, is to disassemble the drive in clean room and inspect the heads under a microscope.
If the OP wants to try to figure out the cause and extent of the failure (but not really concerned about recovery), then I say, have at it.
People who are not in the business think that people who are are being unreasonable, haughty, greedy -- you name it -- when we discourage client interventions. You haven't seen the abortions that we receive nearly every day from clients who "watched a video" and made their drives [needlessly] unrecoverable.
If your PCB have an EXTERNAL ROM chip you should be able to read it with a CHEAP external programmer and a SOIC 8 clip like this :
Regarding that model just go buy an identical drive, remove the heads of that drive and place them back !!! I'm talking about removing the heads of an exact same drive and place the NATIVE heads back. Now try to read the sectors of the drive. Most likely you will not be able to do so and you did ruin the drive.
And we are not even talking about head compatibility and the fact that heads have their own micro-jogs settings that are stored on ROM module, etc .... We are talking about removing the heads from a drive and use those heads tha are calibrated for that drive on it's own drive. Now if you figure out that it've very hard to do so imagine tryng to do the same but with diferent set of heads that are not calibrated for that specific drive, that might not even be compatible, etc.... Try it. But do yourself a favour and buy a drive to test with first. When you decide that you can do a head swap with some confidence then try to get another drive of the same model and swap the heads from one drive to the other, then practice. After some attempts and some heads destroyed let's say 50 or 100 times you can move to the drive with data that you want to recover. Untill you manage to do the head swap procedure on a drive that you don't care about don't even think in doing it on the drive with the data you want to recover.
February 28th, 2018, 10:11
abolibibelot wrote:and at which point the hard disk drive technology may be declining to the point where I couldn't even turn the acquired expertise into a sustainable activity !
February 28th, 2018, 17:25
February 28th, 2018, 17:27
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