Information recovery from a faulty hard disk is a priority direction of my activity. I have got a huge, without false modesty, experience in the given area. The significant part of available assets is spent for purchase of modern software and hardware, allowing to carry out complex operations, purchase of serviceable stores I have not had yet, for completion of available spare parts set, and further studies of internal hardware and software disc structure.
A modern hard disc is a rather complex piece. As a matter of fact, it is a miniature computer having its own central processor, operative memory and operational system. The hard disk system is much more complex, than it might seem at first sight. The basic components which should be noted are a printed circuit board, hermetical unit and the store microprogram. Very often the storage malfunction turns out to be a complex one.
For example, a thyristor effected the computer power unit and has broken down a spindle engine control system chip and the magnetic head assembly of the Hitachi hard disk. Thermal breakdown is visible, so the client says the following: Please, recover the HDD information and replace the burned-out controller. I start malfunctions diagnosis. Soon I see, that together with a burned-out chip on the printed circuit board the processor and the NV-RAM chip (a so called ROM) is burned-out as well. NV-RAM contains not only a head card, but also adaptive information, i.e. displacement which the store takes into account after switching on, before start of microprogram search in the disc service area. Thus, NV-RAM chip program content turns out to be unique. I have to use specialized software and spend a lot of time to fit necessary displacement.
Besides that, system case power unit impulse at the moment of a hard disk failure has burnt out not only the printed circuit board, but also preamplification/commutation chip, located inside the hermetical zone of the head assembly.
Accordingly, to get access to the information from such a storage, I need:
- to find (buy) a suitable serviceable printed circuit board;
- to find (buy) a suitable serviceable "donor" disk to diisemble the magnetic-head assembly and to rearrange it to the "patient" (opening of hermetical unit should be carried out only in the so-called "clean room", a special box filled with dust-free air, where I work using special gateways - oversleeves);
- to fit the necessary NV-RAM displacement, to get access to a service zone and recover original burned-out chip content.
Noboidy expects, that after magnetic-head assembly change the storage will run as a new one. All HDD components are assembled at the factory and have micro tolerance, fine tuning to which occurs as a result of factory self-testing at the final stages of conveyor assembly. Magnetic-head assembly change, even from the disk whose series number differs in one digit, leads to access to working area, though extremely unstable.
For successful copying the information in that case I have to apply specialized software, sector-by-sector copying, various reading algorithms and so on. Certainly, simple change of printed circuit board in the above described case is not enough.
I guarantee confidentiality of all client information recovered. The workstation is not connected to the Internet and only I have physical access to it. As soon as confirmation of the client information reception is gained all the user data are irrevocably deleted of the working computer.
In the conclusion I want to warn of nonprofessional manipulations.
I want to tell you a small story: once a client came to me with a failed hard disk Maxtor IDE 80Gb. He needed to recover information. At switching on the disk I heard unwanted sounds, unusual for normal running and the storage initialization. Even without opening the hermetical unit, just on the basis of my experience, I assumed physical infringement of read-write head positioning actuator which lead to such a gnash.
Unfortunately, the disk was brought to me after multiple non-professional trials of data recovery.
Because of repeated attempts to run the storage and read some data from it the situation was cardinally worsened. All the hermetical zone was covered with metal dust. There were deep scratches on the plates. In such a case not only cost of the information recovery increases in several times but all the procedure becomes under threat of impossibility.
P.S. In section of articles materials about the current problems in information recovery from hard disks are replenished regularly.
If your hard disk failed, or you deleted necessary files, or a spiteful virus spoiled file system - I am at your disposal. I shall do my best to help you.
A. Makarov aka Robin from Sherwood