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.
The new Seagate HDDs are found both in laptops and portable external HDD (Seagate Backup Plus, Expansion Portable).
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
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)
and seen less frequently
- ST2000LM015 – 2TB ‘Barracuda’ branded HDD
Seagate’s engineering name for this series of HDD is ‘Rosewood’.
Challenges in data recovery on ‘Rosewood’ HDDs
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.
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.
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.