Seagate Data Recovery
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It is widely acknowledged that recent models of Seagate 7200.11 series of hard disks have a serious problem with the firmware. There is more detailed information about this problem
available in our Seagate 7200.11 Firmware Problem page.
Common problems where we recover data from Seagate drives are
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Failures in Seagate Hard Disks
A common problem with Seagate drives usually comes after the drive has been accidental knocked or dropped. The next time the drive is accessed it no longer responds.
Our analysis of the problem has revealed that the Fluid Dynamic Bearing (FDB) systems fail resulting with seized bearings. On some of the older drives we found that the bearings were seized when the spindle came into contact with the cover plate for the motor removing small amounts of the cover material (steel). Because the oil in FDBs has magnetic properties and steel is magnetic (can you see where this is heading?) these particles become absorbed into the oil and eventually wedge in between the spindle and the spindle casing resulting in a seizure.
To perform data recovery from drives with seized motors is not easy. It involves the removal of the platters from the drive and setting them into a new housing. The heads then have to be reset, lid and electronics replaced and only then can the recovery status be evaluated.
Platter replacement requires specialist equipment, a minimum of a class 100 clean air system and a very high level of skill and experience in the data recovery engineer performing the work. It is also critical that horizontal and vertical platter alignment is maintained. Data on modern hard disks is written 'through' the platter stack. This means for example with a 4 surface drive (2 platters = 4 surfaces) you may have a file, the first few thousand bytes (or data block) are stored on the first platter surface, the next block on the second surface and so on. So if the alignment is out even a few microns, then the alignment is lost and the drive will be unrecoverable.
Other Firmware Problems
Seagate firmware is accessed in a different way to most other hard disks and is done through a Serial interface on the drive. This is mainly meant for factory testing and refurbishing purposes so unless the engineer is fully conversant with Seagate specific instructions, a potential recoverable drive becomes totally useless. For example there is a Factory command named 'REPAIR' this sounds just like the perfect command to fix the firmware on a drive. It does exactly the opposite. Yes, it does 'repair' the drive, but with irretrievable loss of all the data. It the equivalent of a low level format and completely wipes the drive of all data - including the system area.
During the height of the 7200.11 problem, there was website that posted a method on how to do fix the problem using a serial interface, however there was no explanation of what the commands actually do. And we saw several cases where technicians had attempted recovery but failed. In some cases, they had actually made the problem worse. On newer drives, the fix does not work as Seagate became aware of the site and changed the access method so as to avoid errant command being sent to the drive - we have circumvented the new access modes and can still recover data from Seagate Hard Disks.
Seagate Hard Disks with Electronic Failure
Seagate hard disks have a method of circuit protection on the electronics of the drive. If for example the board detects an over-voltage or spike on the 5v or 12v rails, a component
called a threshold voltage suppressor will blow. Resulting with a dead drive. A TVS is a diode that offers parallel protection to circuits, by either breaking the circuit or creating a new one away
from the circuit it is protecting. Again, another website says to remove the failed TVS and you can access the data. This can in some cases work, however, you need to look at the circumstances
that caused the failure in the first place. If it is a problem in the power supply in the computer, then removal of the TVS can result with a bigger failure as the circuit is no longer protected.
If the TVS that has blown is the one protecting the head stack for example, removal may result with damage occurring to the head stack, again resulting with a bigger problem that is more
difficult to recover the data from. The cause could also be another component failure that results with an over-voltage, so changing the power supply could also have a detrimental effect.
Warning: Do not remove TVSs on the circuit board, doing so puts the data on the hard disk at risk because the circuit protection becomes disabled. This can result in serious damage to
the hard and can also present a fire-hazard !!
Whatever has happened to your hard disk, then consider the value of the data, the cost to replace it (if it is replaceable) then get 2 or 3 quotes for data recovery before commencing any work your self. Data recovery has never been cheap as the equipment needed to do the work is expensive, for example, to equip a single data recovery machine can cost from 5,000 GBP upwards. We have over 20 recovery machines, clean air equipment and advanced electronics benches.
Head Failures
It is the heads that read and write the data, these are precision devices that float over the surface of the platter and respond to magnetic flux patterns. If the heads fail, then data is no longer accessible. The only method of recovery is to remove the old head stack and replace it with a new one. This requires a set of identical heads to the original.
In many cases, it is not the actual heads that fail, but the head preamplifier. This is a tiny electronic device that is attached to the head stack, on older drives it is possible to replace the head pre-amp circuit and use the original heads to recover the data, however, on modern drives the pre amp is not easily accessible and so the only way to recover data is from an identical set of heads.
This is another highly skilled process, the replacement must take place in a minimum class 100 clean air environment and anti-static procedures need to be adhered to throughout the process.
Our Clean Rooms are constantly monitored for particle contamination and results recorded for Audit and have Anti-Static stations that too are monitored for earth bonding.