Seagate “DM001” Data Recovery Methods

CDR – Manchester Data Recovery Services – has noticed a high incidence of failure in the following Seagate 3.5″ desktop drives:

• ST1000DM003
• ST2000DM001
• ST3000DM001

These HDDs are from the ‘family’ of drives with a model number ending, “DM001.” These usually have the Seagate “Grenada” engineering architecture. CDR has observed that frequently the platters on these disks start to degrade and have unreadable sectors. Bad sectors is common a very common sort of disk failure. However, the rate at which these DM001 disks degrade once they have started to fail is alarmingly high. Continued read attempts on a failing DM001 series HDD can quickly lead to a much more serious failure, including firmware failure, head-assembly failure and platter damage. These are described below.

As a consequence of the high rate of degradation it is important to keep a DM001 series disk powered off an seek professional data recovery services. CDR has received a number of DM001 disks in, where owners or PC Shops have left the hard disk reading for extended periods and the end result has been platter damage. This platter damage has then resulted in all data being unrecoverable.  Use of appropriate disk imaging equipment (DeepSpar, PC3000) is essential to avoid unnecessary wear on the failing HDD.

Firmware failure

Due to the large number of bad sectors it is frequent for the HDD’s firmware to fail. Failure usually relates to the bad sectors being assigned to the  ‘Growth Defect List’ (G-List). A typical scenario of firmware failure is when the disk powers on and sounds normal. However, it is not recognised by any computer. In this case it is necessary for key functions of the HDD to be disabled. When powering the HDD on an AceLabs PC3000 the HDD will frequently get to a ‘ready’ state. However, when any command is sent to the HDD it will give a ‘busy’ status and will no longer respond to commands. It is necessary to send commands via a terminal connection and alter the Saved Mode Pages and to disable a number of the functions (see below).

Some cases of firmware failure can be more complex and require more advanced methods to allow the data areas of the HDD to be accessed.

Challenging mechanical failures

For the DM001 series HDD there can be a relatively short period between media degradation and read-write head failure. Failure of the read-write heads is normally indicated by a clicking sound. These Seagate HDDs will usually ‘spin up’, then make a number of clicks, and then spin down. The drive will appear to then be powered off. However, the printed circuit board (PCB) is still live.

Access by terminal connections gives a distinctive output. Below is a screenshot providing the terminal output of a ST3000DM001 with a head-assembly failure.

Typical terminal output form a Seagate DM001 series HDD when the read-write heads have failed

Boot 0x40M
Spin Up
FAIL Servo Op=0100 Resp=0003
ResponseFrame 05C0 0051 03B4 2D40 0008 0000 0000 0000 0FC7 0000 0000 0000 0000 0000 0000 0000 09AA EB88 40A8 2CDC EAA3 BC0F 7850 E686 B707 735E 0000 007F 0000 0000 001F 0004 0010
FAIL Servo Op=0100 Resp=0003
ResponseFrame FE40 0054 03B4 2D80 0008 0000 0000 0000 0FB9 0000 0000 0000 0000 0000 0000 0000 09AA EB88 40A8 2CDC EAA3 BC0F 7850 E686 B707 735E 0000 007F 0000 0000 001F 0004 0000

When replacing the mechanical components of the DM001 series of disks there are a number of challenges. Donor parts can be hard to match due to variations in the pre-amplifier and the head-map. It is not possible accurately determine these by manufacturer label on the outside of the HDD. This means that we frequently have to try a number of different donor drives before a match is found. However, all of our quotations include the cost of up to three donor HDDs.

A common fault discussed

Information on hard disk drive failure can be found on the HDDGuru forum. It is also a place where data recovery professionals discuss matters to HDDs and SSDs that they have in for recovery. The DM001 series is discussed widely, including the requirements and limits of recovery. Inspection of this forum will reveal that the DM001 series HDD is regarded very poorly by data recovery professionals.

Below is an image of a ST3000DM001 which was examined by CDR. Prior to receipt this HDD had been handled by a PC Shop which had made a number of unsuccessful recovery attempts on the HDD, and they reported that the disk degraded during their recovery attempts. In this case there was damage to the top surface of the top platter. This HDD is unrecoverable by any data recovery company. Unfortunately we see many instances of this type of media damage in Seagate DM001 series hard disk drives.

There is a relatively high incidence of media (platter) damage in Seagate DM001 series hard disk drives.

Contact a professional

For the best opportunity of a successful recovery in Seagate DM001 hard disk drives it is worth contacting CDR at the first instance of failure. Please keep the hard disk drive powered off.

The post HDD Failure: Seagate “DM001” series appeared first on Cheadle DATA Recovery Ltd.

Case study: Toshiba MQ01ABF050 – skewed spindle

An unusual failure in a Toshiba  MQ01ABF050 500GB 2.5″ laptop hard disk drive (HDD). The owner of the laptop had fallen down a flight of stairs whilst carrying the laptop. As a consequence the HDD sustained a significant physical shock.

On arrival the HDD emitted a buzzing noise. The most common reason for this is when the read-write heads get stuck to the platter surface, which prevents the motor from spinning. Usually the motor bearing itself is OK. A less common failure is when the bearing itself fails, which prevents the motor from turning at all. These are typical mechanical failures of a HDD.

However, the fault in this HDD was very unusual.

Clean room inspection

When the HDD was opened the head assembly was parked in the landing ramp. It was not possible to rotate the platter. Assuming a motor bearing failure the head-assembly and the landing ramp were removed in preparation of performing a platter swap to a donor hard disk assembly. On removal of the landing ramp it was possible to rotate the platter freely.

There was an initial suspicion that the plastic landing ramp itself had become misaligned or damaged. A donor landing ramp was refitted. The fault in the HDD was replicated.

A thorough inspection of the HDD took place. It became apparent that when the landing ramp was fitted that the platter was not passing freely through it. That is, the landing ramp was pressing against the platter, which prevented the platter from spinning.

Skewed spindle

The physical shock had skewed the spindle of the hard disk drive. When the platter rotated it did so with a small, but significant ‘wobble’. Please view the video below showing the failed drive and this unusual failure of the spindle motor.

Successful recovery

The platter was swapped into a donor hard disk assembly. The platter rotated correctly without any misalignment. The original head-assembly of the failed HDD was used, which had retained full functionality despite the physical shock. It was possible to make a full recovery of the data.

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26/06/2017 – Western Digital 4TB (4000GB) – CCTV Deleted video

Requires deleted / lost footage to be recovered. The drive was part of a CCTV recorder. The data required is part of a legal defence.

In this case, there is the use of a Linux Ext4 filesystem. This presents some challenges for the recovery of deleted files due to updating of the inode structure. Significant amounts of new data have been written to the hard disk drive (in the form of more recent video), resulting in significant amounts of corruption in deleted files. The hard disk drive has good electronic and mechanical functionality. A complete sector by sector disk image was obtained within a few hours.

Hard disk drive details:

Manufacturer: Western Digital (Purple Surveillance Series)

Model: WD40PURX-64GVNY0

Printed Circuit Board: 2060-771945-002 REV A

Result:

The recovery of many hours of working footage, but with corruption in some files due to new data having been written to the HDD. The customer has been given the option to determine whether the correct data they require has been recovered OK before payment.

The post WD 4TB CCTV Deleted video appeared first on Cheadle DATA Recovery Ltd.

27/06/2017 – WD 2TB My Passport – Dropped on the floor

A 2TB (2000GB) Western Digital My Passport Ultra portable HDD was dropped by the customer on the floor. The HDD made some quiet clicking noises and was not recognised by his Apple Mac or Windows computers. From the initial telephone diagnosis of the HDD, it was not possible to determine whether there was a failure of the read-write heads as a result of a physical shock. The most common reason for a mechanical failure of an HDD is a physical shock.

Hard disk drive details

Manufacturer: Western Digital

Model: WD20NMVW-11AV3S2

Printed Circuit Board: 2060-771961-001 REV A

Main processor: 88i9446-NDB2

Motor controller: WD Nautilus A21V599

Diagnosis of the fault

A full diagnosis was completed. In the received state the HDD was not recognised by any equipment or diagnostic equipment. It was necessary to remove the native USB-integrated printed circuit board (PCB) and swap this with an equivalent SATA PCB. Making changes to the ROM code allowed access to the firmware in an engineering (kernel) mode. From here it was possible to assess that the firmware had failed due to a large number of read errors. The drive was suffering from the ‘slow-responding’ firmware fault. This was corrected, and it was possible to initialise the HDD to a state where attempts to read the user data could be made. The HDD was using the Western Digital Self-Encrypting Disk function where the owner of the HDD had applied a password to secure the data. We were able to remove this ‘security’ feature without the need of the original password due to the weakness in Western Digital’s application of the security protocol.

The result

Testing showed that of the eight read-write heads inside the HDD, two had weakened due to the physical shock. However, all heads still had reasonable functionality. It was possible to provide a quotation to the customer for the recovery of the data without having to replace the mechanical components of the drive. The drive is currently imaging on AceLabs PC3000 disk imager. A very good result is expected.

The post WD 2TB My Passport Dropped on the Floor appeared first on Cheadle DATA Recovery Ltd.

28/6/2017 – HDD read/write heads detached

A Western Digital My Passport 500GB was received for recovery. The drive was spinning, but an audible clicking and scratching sound could be heard. The HDD had sustained a physical shock, which had caused failure.

The HDD has a total of three read-write heads assigned to four platter surfaces. Numbered 0, 2 and 3. When the head-assembly was removed it became apparent that read-write head 2 had become detached from the head assembly and was missing.

If a read-write head is missing then it is likely it became stuck on the platter surface at the point of failure. This is problematic, as the metal head assembly is now exposed, and can potentially make contact with the platter surface and cause physical damage to the platter.

Head #2 has become detached from the head assembly. Head #0 is present and shows no visible physical defects.

Hard disk drive details:

Manufacturer: Western Digital

Model: WD5000BMVW-11AMCS4

Printed Circuit Board: 2060-771814-001 REV P1

Result:

On attempting the work it became apparent that there were small but significant, amounts of silver coloured fragments displaced inside the HDD case. These fragments are parts of the platter surface. The donor parts provided some functionality to begin with. The drive would calibrate, but no data was readable. After numerous calibration attempts the donor parts gradually degraded until they were completely unresponsive and have failed.

In this case there is physical damage to the platter surface, known as a ‘head-crash’. It is not possible to recover data in these circumstances.

No-recovery, No-fee

No charges were made to the customer for the work completed, or the donor parts which were used and destroyed during the recovery attempt.

Pictured above, shows the use of metal head-combs as supplied by HDDSurgery, to allow for safe removal and replacement of the head-assembly.

The post Detached read-write heads appeared first on Cheadle DATA Recovery Ltd.

30/6/2017 – ST4000DM000 – Contamination inside the disk

A Seagate ST4000DM000 hard disk drive was received from a Manchester based media company. The HDD was from an external “Backup Plus Hub” USB3 caddy, and had been knocked off a desk by one of the employees whilst he was working on a project. The drive contains many gigabytes of video footage and the associated Adobe Premier editing project files.

On arrival, the HDD was making a buzzing sound. The platters would not spin up. Initial diagnostics suggested that spindle motor was seized as a result of bearing failure, or the head assembly being parked on the platter surface. This is a mechanical failure.

This model of Seagate HDD has a locked diagnostic port, with an encrypted service area. Consequently, certain alterations to the firmware are either very difficult or impossible to achieve at the time of writing.

Above, opened ST4000DM000. Heads are parked on the platter surface. There are silver coloured fragments located in the drive (circled in white).These are likely to be parts of the damaged platter surface. A recovery was possible.

Hard disk drive details:

Manufacturer: Seagate

Model: ST4000DM000

Part Number:

Printed Circuit Board:

Recovery result:

The hard disk assembly was cleaned of contamination. The heads were removed from the platter surface and inspected under magnification. Head #3 showed signs of some physical damage. The head assembly was replaced with that of a good matching disk. The repair of mechanical components was successful and it was possible to initialise the HDD to a reading state. Selective head imaging was completed to read from heads 0, 1, 2, 4 and 5 before read attempts on head 3 took place. This was to minimise the risk that the donor parts would fail to avoid reading the platter which was most likely to be damaged.

This work has taken place today, and the HDD is now cloning with a small number of read-errors. We expect to recover 99.9% of the data OK.

The post Seagate ST4000DM000 4TB damaged platter appeared first on Cheadle DATA Recovery Ltd.

22/7/2017 – ST3000DM001. Pre-opened HDD

This week CDR – Manchester Data Recovery Services – received a 3TB HDD from a media company based in Sale, Cheshire. The drive contained video footage for various projects. The owner of the HDD had described that the drive had been making a ‘clicking’ sound. Knowing this, and that the model of the drive in question was the Seagate ST3000DM001, it was possible to identify over the phone that the drive was most likely to have a failure of the read-write heads. This is a mechanical failure of an HDD and is the most serious type of failure. Consequently, the fees associated with this type of recovery work are at the top end for data recovery services. A full copy of our price list was sent to the customer.

Severe physical damage to the platter, and large amounts of contamination in the filtration pad due to the platter surface having been scraped away by the head assembly. Almost certainly an unrecoverable HDD.

Hard disk drive details:

Manufacturer: Seagate

Model: ST3000DM001

Printed Circuit Board: 100664987 REV A

Receiving the HDD

On receipt of the HDD, it was obvious that the HDD had been previously opened. The manufacturer label on the front of the HDD had been tampered with, and the screw which holds the head-assembly in place was exposed. There was a sticker on the front of the drive which we recognised as that of another data recovery company. The owner of the disk confirmed that the drive had been sent to another company first, but he had requested back on the basis of their quotation.

False advance price estimates and diagnostic tests

The customer had been told in advance by the first data recovery company that the ‘average’ cost of recovery would be about £200. The website of the said data recovery company clearly advertised “no-recovery, no-fee,” and this had been stated to the customer. On receipt of the customer’s disk, this changed. He was provided with a quotation where the total cost was nearly £1000, with approximately £300 upfront, non-refundable fees for donor-parts to attempt the work. They claimed that the chances of successfully recovering the data were about 70%

Scam in action

We opened the HDD and performed an inspection in a clean air environment. It was immediately apparent that the HDD had suffered catastrophic damage to the platter surface. This was visible and is documented in the image. Moreover, there were large amounts of contamination inside the drive as a result of this damage. In a very low proportion of cases it is possible to recover data from disks with minor platter damage. However, to claim that there was a “70%” chance of a successful recovery was false. On this occasion the location and severity of the damage would almost certainly make any data unrecoverable.

Non-refundable fees

It is cases like this are the reason why that we urge customer of data recovery companies to never pay a non-refundable fee for data recovery services. There was clearly little or no chance of a successful recovery in this case. Yet the company made false claims and requested several hundred pounds in fees to attempt work. Work, which we expect was unlikely to take place at all.

In this case Cheadle DATA Recovery Ltd made no charges for the diagnostic tests performed on this HDD.

The post Data Recovery Scam Example – Inform yourself appeared first on Cheadle DATA Recovery Ltd.

28/07/2017 – WD20NMVW – Failed Read-Write Heads

A 2000GB (2TB) portable HDD was being used by a furniture design company to store data associated with their newly designed products, as well as some archive data associated with the business. Their last complete backup of all the data was approximately eight months prior to the failure of the HDD. On diagnosis, the HDD was making a distinctive clicking noise. The read-write heads had failed inside the HDD. This is a mechanical failure of the HDD. The drive required repair to allow access to the data.

Hard disk drive details:

Manufacturer: Western Digital (WD)

Model: WD20NMVW-11AV3S4 (My Passport)

Printed Circuit Board: 2060-771961-000 REV P1

Result:

Donor parts were required to work on this HDD. The cost of these was included in the original quotation. On replacement of the head assembly the HDD initialised well. However, there were a considerable number of read errors on heads #5 and #6. The drive had a total of 1700GB of data on. It became apparent early on that the HDD would not remain stable enough to read the entire HDD.

It was possible to read the Master File Table (MFT) which creates the folder and file name structure. From this, it was possible to filter data with in PC3000 Data Extractor. This allowed a recovery attempt on only data which had been modified since the customer’s last complete back up several months ago. This accounted for just 30GB of 1700GB of data on the HDD.

Targeting only this data allowed for nearly a complete recovery of the critical business files in a relatively short period of time. If the complete drive had required imaging then it would have been likely to take 2 – 3 weeks to complete, even if read-write heads #5 and #6 would stay operational during this extended period.

Return of data

The data was returned to the customer. The customer later on stated:

Amazing service from initial contact to final recovered data. The online updates on progress and the professionalism throughout the process was second to none.We would recommend John at Cheadle Data Recovery as the first point of call for any data loss issues. Thank you for this professional and well informed service.

The review can be found on the CDR Google Maps Listing.

The post WD20NMVW mechanical failure appeared first on Cheadle DATA Recovery Ltd.

23/8/2017 – Seagate 2000GB external HDD – not detected by any computer

A Manchester city centre based Landscape and Ecology consultancy had a considerable number of design files for clients on an HDD which failed. No clicking sounds could be heard from the failed HDD. However, the HDD could not be detected by any Windows or Mac OS computer.

In a phone diagnosis, it was possible to determine that the series of HDD was a Seagate ‘DM001 Grenada’ disk. These are well known in the data recovery industry as a result of the relatively high failure rate and challenging recoveries. Our Seagate DM001 series case study provides information on this. A fixed price quotation was provided based on the suspected fault with the HDD.

Hard disk drive details:

Manufacturer: Seagate

Model: ST2000DM001 / 1CH164-302

Printed Circuit Board: 100687658 REV C

Result:

The HDD had a failure of the firmware. The disk would not initialise fully and would be stuck in a ‘busy’ state. It was not possible to read any data from the HDD, and the HDD would not respond to any commands via the SATA interface.

It was necessary to alter the ‘Saved Mode Pages’ via the terminal connection within PC3000. After this, it was possible to get some access to the HDD and the data. However, read speeds were poor. This was due to a more complicated failure with another module of the firmware, referred to the ‘media cache’. After extensive alterations to the firmware, it was possible to allow the HDD to enter a stable read mode. It took approxcimately four complete days of disk imaging to recover the data.

Of the 1200GB of data stored on the HDD, it was possible to recover all but 2.5GB of data OK. A full recovery of the critical data was made. The 2.5GB of corrupt files were not of significance to the customer. CDR provided an opportunity to the customer to check that the data they required had been recovered via our File List Viewer software.  The customer left a review on the CDR Google Business listing for the work completed.

The post Seagate 2TB Backup Plus – not detected appeared first on Cheadle DATA Recovery Ltd.

Repair of Seagate ST2000LM007 and ST1000LM035

During quarter three of 2016 Seagate started to manufacture a new generation of 2.5 inch hard disk drive. For the previous 4 years to this Seagate had relied on Samsung technology based HDDs in the form of the M8 and M9T series. The most common model being the ST1000LM024 / 25. Seagate acquired Samsung HDDs in December 2011, and used the Samsung 2.5″ disk technology for drive manufacture.

Are these the worst hard disks ever made?

Considering these HDDs from a reliability / data recovery point of view, then we would have so say, from the current experience at CDR, that these HDDs present as some of the least reliable HDDs made. Moreover, they present as some of the most challenging disks we have seen in recent years to achieve a completely successful recovery of the data.

All hard disk drive manufacturers have at some point their history produced a poorly designed HDD which has higher than average failure rate. The IBM 75GXP is particularly noteworthy. However, these new models of Seagate HDD really stand out. Premature failure is a major issue. Many of our customers present these disks after owning them for only a few weeks or months. Secondly, the typical failure found in these HDDs is relatively severe. The HDDs can be highly degraded with bad sectors, and have complex firmware faults. Moreover, in the majority of cases the HDDs arrive with failure of the head-assembly. In short, these disks degrade over a relatively short period compared with other HDDs.

The model number for the two HDDs seen frequently are:

• ST1000LM035 – 1TB (1000GB)
• ST2000LM007 – 2TB (2000GB)
• ST2000LM015 – 2TB ‘Barracuda’ branded HDD

Seagate’s engineering name for this series of HDD is ‘Rosewood’. These ‘Rosewood’ disks are frequently found as portable external hard drives, and OEM branding includes the following:

• Lacie – Rugged Mini LAC301558/LAC9000298, Porche design USB C including Thunderbolt
• Latest Seagate expansion – STEF1000401, STEA1000400, STEF2000401, STEA2000400
• Latest backup Plus – STDS1000900 & STDS2000900
• Maxtor – HX-M101TCB/GMR & HX-M201TCB/GM

Challenges in data recovery on ‘Rosewood’ HDDs

Change to physical design of the HDD

This presents itself immediately. The HDDs are designed with a height of 7mm, but have the ability to contain 2 platters. Previously, the limit of 7mm height HDDs was to contain a single platter. To achieve this it has been necessary to redesign the HDD completely.

The printed circuit board (PCB) now occupies only a small proportion of the base of the HDD. This allows the black metal casting of the hard disk assembly to be extended.

There is no longer a complete lid to the HDD. The top most part of the drive is composed of a partial metal lid. This is very thin compared with previous HDDs. The lid meets to the top magnet of the actuator. For this series of drive the manufacturer label has a critical function. It seals the drive and prevents airflow between the actuator, the lid and the casting of the hard disk assembly. As consequence, when these HDDs are worked on it is critical to reseal the HDD appropriately to ensure that the air pressure within the HDD reaches the correct levels when the HDD is powered on. Moreover, incorrectly resealing the HDD could allow for contamination to enter the HDD.

In Rosewood HDDs the read-write heads (sliders) on the tip of the head-assembly are considerably more fragile than those found in other 2.5″ HDDs. If the heads make contact with the platter surface then there is a very high likelihood that there will damage or misalignment of the head. The change in shape of the PCB has resulted in the pre-amplifier connector now being located very close to the off-ramp. As a consequence the traditional method or removing the head-assembly is no longer possible. Instead, head-assembly replacement requires the read-write heads to be moved over the surface of the platter to then allow for removal of the off-ramp. This is a more challenging operation compared with previous generations of HDDs.

The key changes at a glance:

• 1000GB per platter media density allowing for higher read speed
• Media cache function, to allow faster access of frequently used files
• 7mm “ultra thin” disk height
• Significantly reduced weight and power consumption

Locked diagnostic port

Seagate have locked the ‘diagnostic port’. The diagnostic port (or terminal connection) are accessed by the 4 pins which are located near the SATA data cable connector on the printed circuit board. This port is normally used during work on Seagate HDDs to send commands directly to the HDD and read data from the service area (firmware) when the HDD has failed and is unstable.

To allow access to the diagnostic port it is necessary to alter code found in the serial flash ROM chip. Once complete many, but not all, operations using the diagnostic port can be completed.

Highly degraded media and complex firmware

The platter surface degrades readily, resulting in bad sectors. Functions in the firmware attempt to reassign these. However, due to the large number of defects the firmware enters an inaccessible state.

Typical symptoms include:

• HDD is detected by computer, but computer hangs or pauses.
• HDD is not detected by the computer, but sounds ‘normal’. There are no clicking or buzzing sounds.

The firmware in Rosewood HDDs is more complex than in previous Seagate HDDs. For example performing operations like ‘translator regeneration’ without backing up critical firmware modules can result in permanent data loss. Defects in the ‘Media Cache’ are also particularly problematic. Consequently it is necessary to work with great care when altering the firmware on these HDDs.

High incidence of physical damage to the platter

Finally, and most significantly, there is a higher than average incidence of damage to the platter in Rosewood HDDs. In many cases this is visible when the HDD is opened. For these HDDs there is usually no possibility for a recovery attempt. For HDDs where a recovery attempt is possible we find that donor parts (a head-assembly from a matching HDD) have a high likelihood of being damaged during read attempts on the HDD. Frequently it is necessary to use multiple donor parts to get an adequate result for the customer. Please note that CDR includes the cost of any donor parts in the quotation, and there are never any up-front or non-refundable fees.

Opinions from other Data Recovery Professionals

Data recovery professionals discuss storage devices and recovery techniques in the forum HDDGuru. If you perform a search for the term ‘Rosewood’ or the model number ST1000LM035 or ST2000LM007, you will find a number of posts dedicated to this HDD. The reviews on this series of HDD are generally negative, with most professionals noting the considerable challenges faced whilst working on these disks.

The post ST2000LM007 / ST1000LM035 – Is this the worst HDD ever made? appeared first on Cheadle DATA Recovery Ltd.

21/2/2019 – Seagate 1000GB 7200.12 Barracuda

A desktop HDD provided by an IT Support company on behalf of their customer. The HDD was making a distinctive clicking sound. Quickly it was possible to establish that the HDD has a failure of the read-write heads. To attempt to recover data it would be necessary to replace the failed head assembly. This is a ‘mechanical failure’ for the purposes of pricing.

Hard disk drive details:

• Manufacturer: Seagate
• Model: ST31000528AS
• PN: 9YP154-521 .
• SN: 9VP…
• Firmware: JC4A
• Site Code: TK
• Printed Circuit Board: 100535537 REV A

Result:

Use of a matching donor HDD was required. Seagate 7200.12 series HDDs have a head-assembly which parks on the platter surface when powered off. This means that the read-write heads make contact with a demagnetised area of the platter near the spindle motor. This means that it is necessary to retract the head-assembly off the platter surface for replacement. For this, we use specialist tools manufactured by HDDSurgery. The particular tool used allows for removal of the head-assembly without causing the read-write heads (sliders) to make contact with the area of the platter where data is stored. This minimises the chances of damage to either the read-write heads or the platter.

This method of head-assembly removal is preferred and is the choice of professional data recovery services. Attempts to ‘drag’ the head assembly across the platter to mount on plastic head-combs should be avoided, as there is a greater likelihood of damage to occur, and consequently a lower chance of a successful recovery.

Once the head-assembly was replaced in the failed HDD, it was necessary to import the ‘head adaptives’ from the ROM code. At this stage, the HDD would only partially calibrate. It was necessary to read the firmware via the terminal connection and then make appropriate alterations, including clearing of the G-List.

Once completed it was possible to start reading the data within PC3000 Data Extractor. A full recovery of the critical data was possible.

Detailed technical information for data recovery professionals:

HDD: Pharaoh
Product FamilyId: 3F, MemberId: 03
PreampType: 71 03
Servo FW Rev: B780

• It was necessary to import head-adaptives.
• The HDD would click when powered on but after two minutes would reach ‘RDY’.
• F3 T> access was available.
• Any ATA command would result in the HDD entering BSY.
• Critical SYS files were read via terminal.
• There were read errors in the SMART sys files, and faults with the G-List / Alt-List.
• It was necessary to clear SMART and Alt-list via terminal commands.
• After this direct access via ATA was possible.
• The disk would still occasionally making ‘clicking’ sounds, but when imaged in Data Extractor read very well with few errors.

Error messages in terminal log:

Rst 0x20M
RW: Disc Ctlr Initialization Completed.
(P) SATA Reset

RAW OFF
PASS
RW: Error processing Performance Parameter File: 203C
Rst 0x20M
RW: Disc Ctlr Initialization Completed.
(P) SATA Reset

RAW OFF
PASS
RW: Error processing Performance Parameter File: 203C
Starting LBA of RW Request=05B2C270 Length=FFFFFFFF

The post Head-assembly swap: Seagate ST31000528AS appeared first on Cheadle DATA Recovery Ltd.

Micro-Jogs and the use in Data Recovery

The “Micro-Jogs” of a hard disk drive refers to the distance between read and write head elements calculated by the manufacturer. The values are used to slightly move the centre of read/write heads over the centre of the track for fast and reliable reading and writing. Essentially, the values are used for ‘fine positioning’ of the heads. Micro-Jogs are primarily found in Western Digital Drives.

The Micro-Jog values are calculated during the manufacturing process. These values are stored within the contents of the ROM.

When working on a WD disk we extract the contents of the ROM and check the values of the Micro-Jogs. Once we know the values for the failed (patient) HDD, it is possible to compare these to the values in donor HDDs. Having a good match of the Micro-Jogs in the patient and donor HDDs allows for the best possible compatibility in the head-assembly.

Case Study – When Micro-Jogs were critical to recovery

A Western Digital 500GB WD5000AAKX was being worked on as a result of a failure of the head assembly. The patient’s read-write heads/sliders were severely misaligned. Such severe misalignment can lead to physical damage to the platter surface, which in turn can make data recovery impossible.

Tolerance in Micro-Jog parameters

Typically, any patient and donor HDD should have micro-jog values within 200 of each other, across each of the read-write heads. Values of up to 300 are acceptable, but can potentially be problematic. Differences between head micro-jogs with values higher than 300 usually do cause problems, either with complete lack of functionality, or very poor performance.

Incompatible donor HDDs

Typically when locating a suitable donor Western Digital donor HDD we look for a match on the model number. An exact match on the model number in itself is not critical, but it tells us which engineering revision the HDD is from. In this case the Tahoe LT series. Next, an inspection of the “DCM” configuration, listed on the manufacturer label. In older generations of the HDDs, this used to critical to match parts of the code between the patient and donor HDD. However, we have found that for disks manufactured from 2010 onwards this has become less important. Nevertheless, it always helps to have it match than not.

Given the DCM code on our selection of donors, we decided to use a donor which matched the DCM, family series and firmware revision with that of the patient HDD. However, the Micro-Jogs had a difference of between 400-500. Use of this donor head-assembly allowed for partial calibration of the HDD, but it was not possible to read the user area of the platter. It was possible to read some firmware modules, but physical read errors were occurring. Testing with another HDD with similar micro-jogs to the first donor replicated the symptoms.

The correct donor HDD

Given the above, we looked for donor HDDs with a better match on the Micro-Jogs, even if other parameters (like the DCM) were not a good match. Use of donor with micro-jogs between 0 and 200 for the heads improved matters significantly. With this donor head assembly, it was possible to initialise the HDD fully and read the service area. Moreover, the HDD read the user data area well, with just a small number of bad sectors.

An alternative to a good donor – Micro-Jog averaging

In the case study above, it was possible to locate an HDD with close enough Micro-Jogs. However, in some jobs, it is simply not possible to locate a suitable donor. If this is the case then we can re-program the micro-jog settings in the patient, to match more closely the micro-jogs of the donor. This is known as “Micro-Jog Averaging”. This is performed within PC3000 and can allow for. The results of this can be unpredictable, which is why it is always better to find a donor which has a close match on the patient HDD’s micro-jogs.

Advanced Data Recovery Services

Cheadle DATA Recovery Ltd provides advanced data recovery services and frequently recovers data from hard disk drives which other data recovery companies do not. Each month CDR receives multiple disks which have been opened at other data recovery companies and have been declared as ‘unrecoverable’ due to either lack of appropriate work or donor parts. If you have important data you require recovering please contact CDR.

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‘Sticktion’ – the head-assembly is stuck on the platter surface.

A common fault in the failed HDDs that CDR receives. The customer reports that the HDD is making a buzzing or a beeping noise. It is usually possible to diagnose the HDD during a phone conversation. The buzzing or beeping noise is being emitted as the spindle motor has seized. In 2.5″ HDDs, this is usually because the head-assembly has become stuck on the platter surface which prevents the motor from turning. In 3.5″ HDDs failure of the motor bearing itself can occur. For the purposes of pricing, this is treated as a ‘mechanical failure’ in CDR’s price list.

Below is an image of an HDD that CDR was working on during April 2021. It is a Seagate ST2000LM007 ‘Rosewood’ HDD. These HDDs are notorious in the data recovery industry for a high failure rate and for being challenging to work on. The image below shows one of the reasons why these HDDs can be challenging. The HDD had failed as a result of ‘sticktion’. The image shows the HDD with the head-assembly, off-ramp and top magnet removed. On the top platter surface, it is possible to view the read-write head/slider. This has detached from the head-assembly. This is much more common in ‘Rosewood’ Seagate HDDs than other models of HDDs. Removal of the slider is challenging as it is necessary to perform this without causing damage to the platter surface. It is particularly challenging if the detached slider is on a lower surface of a platter.

Replacement of the head assembly

It is necessary to ensure that all detached sliders have been removed from the platter, or located within the hard disks assembly. Only once all of the sliders have been accounted for can replacement of the head-assembly take place. If sliders remain on the platter, and the head-assembly is replaced, and then powered on, then it is very likely that physical damage shall be caused to the platter surface.

Please do not follow DIY guides on YouTube

Whilst YouTube might have helpful videos on how to erect new shelves or plumb in a washing machine, the videos that DIY-ers post regarding hard disk drive data recovery are usually irresponsible. CDR receives a considerable number of HDDs that have been previously opened. On many occasions, the person who has opened the HDD has made a recovery of data impossible by mishandling the HDD.

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