Data recovery from a dead Sony Vaio and how disk lubrication can prevent permanent data loss…

Last week, a customer from Dublin contacted us needing data retrieval from their old Sony Vaio laptop. The customer, an architect, recently removed the system from a storage cupboard in his office. Its hard disk contained drawings of a project which he had completed in 2008. Recently, he got the green light for a very similar project. If he could salvage these old drawings (stored in DWG format) along with planning permission files (Word and PDF) from the laptop, he could save himself a lot of time and expedite the planning permission and design process for his customer. Could we recover this customer’s Vaio’s hard disk?

The Vaio laptop running Windows 7 laptop was no longer starting up. The system was completely dead. We opened up the laptop and removed its Seagate Momentus 640GB disk (ST9640423AS). When attached to one of our Windows systems via S-ATA cable, it failed to mount. So, we connected it to one of our data recovery systems to peform a more detailled diagnosis. However, our tests to analyse the platter surface and disk-heads could not even run because the disk was not spinning. Though we did get a succesful identification of the disk’s firmware family and version number. In our clean-room, we opened the disk. The heads were not parked on the disk ramp, but rather precariously positioned in the middle of the platters.

This is not ideal because an adhesive bond can form between the disk-heads and the platter surface. This is known as “stiction” and used to be a big issue for electro-mechanical disks until “ramps” or “parking areas” were incorporated into disk designs. This design change resulted in the stiction problem being more or less eliminated for disks being stored in ambient temperatures. However, in this case, the disk evidently experienced a sudden shut down and the head-disk assembly (the component on which the disk-heads are mounted) never got an opportunity to “park”.

Using specialised tools, we “unstuck” the heads from the platter surface. This procedure needs to be performed extremely delicately. An exertion of force can lead to platter or disk-head damage whilst too little force can result in the disk-heads remaining stuck. Drive Rescue use a number of finely tuned processes and tools to perform this task in the safest possible way.  

Perfluoropolyether – the hard disk super-lubricant

In this case, while the HDA was not in a “parked” position, there is another feature of hard disk design which helps mitigate against stiction events. Manufacturers apply a very thin layer of perfluoropolyether (PFPE) to the platter surface. This “super-lubricant” is a colourless synthetic oil commonly applied to HDD platters because of its durability, chemical inertness and good cohesiveness with the platter’s carbon layer. If a minor scratch does occur, the composition of PFPE exhibits just the right amount of viscosity to replenish the disk areas that have been depleted of lubricant. Its cohesiveness means that the lubricant remains in-situ, even with the constant stress of air-flow that is generated by the slider as it moves over the platters. The qualities of PFPE also mean that it can also prevent the disk-heads forming a strong metallurgical bond with the platters.  

While PFPE might sound like a lubricant that Captain Kirk might use for greasing up the old Starship Enterprise, it is not faultless. At high temperatures, the efficacy of this super lubricant reduces, increasing the risk of tribological events, i.e. the read or write elements that come into direct contact with carbon or magnetic layer on the disk. In this case, however, PFPE seems to have done its job well. (The ambient temperature of the office where the customer stored the host laptop no doubt helped). While the disk-heads and platter had collided, they were joined by only a weak bond. If the bond had been stronger – disk-head or platter damage would have been inevitable. Thus, the need for a full head-disk assembly replacement was negated. The delighted customer was reunited with all his historic work, which was presented to him on an external USB drive. He now had some extra free time in the summer and would not have to backtrack on work he had previously completed.

Drive Rescue, Dublin, Ireland have been recovering data since 2007. We offer a complete recovery service for non-booting, unreadable or damaged disks from Sony Vaio (E, PCG. VGN-Z and VPC-Z) series of laptops. This includes disks such as the Seagate Momentus ST500LT012, ST9640423AS, HGST Z5K-500, HGST Z5K1000 and the Toshiba MQ01ABD050