Data loss is one of the worst possible imaginable catastrophe that can effect a business establishment or individual PC users. People encountering such a problem immediately try out various recovery programs. Before any attempt is made at possible data recovery, the user should first identify if data has been lost due to a physical or a logical damage.
Physical damage can occur when computers fall down, are damaged by water or excessive heat. The extent of the damage can only be ascertained by data recovery experts. People commonly believe that natural disasters cause the maximum physical damage. But, on the contrary, just 1% of the physical damage to a computer occurs due to nature’s fury.
Symptoms of Physical Damage to the Hard Drive
- If the system BIOS, or other disk utilities software such as Windows, etc. cannot access the hard drive it is a dead drive.
- Apart from inaccessibility, a dead drive will also not spin, or make unusual noises when the power is switched on. If a clicking noise is heard, it is the hard disk scratching the magnetic surface of the platters. This is referred to as a head crash. A damaged disk span produces a similar noise, for the read head tries to read from the damaged surface. Failure to read produces repeated attempts and thus the noise. 6% of the physical damage is caused by bad sectors that turn data unreadable.
- Loose components, or defective spindle and read write head also cause unusual noises. The computer should not be used in such circumstances.
- Physical damage also leads to the logical structuring of the file getting altered.
A physical damage to the hard drive leads to a loss of productivity, threatening the very survival of a business establishment. 40% of entrepreneurs said that computer-related problems and loss of productivity for three days harmed their business greatly. Over 15% said that they can afford to manage without access to data for just a day. And, for 4% of the users just one hour of data inaccessibility is enough to cause serious problems.
As data is so vital to the functioning of an organisation, computer users often create a backup for all their data. But even backup files get affected by a range of physical problems. Data is lost when the metallic surface of the CD-ROMs get scratched. Tapes might break with time.
Individual PC users often find it difficult to retrieve data that is lost due to a physical damage. Hard disks have to be opened in class 100 clean rooms.
Data Recovery Companies
Data recovery companies open the hard drives in class 100 or even class 10 clean rooms.
- They replace the damaged components
- The damaged Printed Circuit Board (PCB) is removed and replaced by a matching PCB from a good hard drive.
- If the read/ write head is damaged it is replaced by a matching part from another drive.
- Hard disk platters are removed from the damaged drive and reinstalled.
- Physical damages sometimes lead to a logical damage. These companies also logically restructure to enable data recovery. Once this process is complete the files come in a usable form.
Problems Faced in Physical Data Recovery
- Data recovery from the damaged hard drive is dependent upon the extent of the damage. Extreme heat demagnetises the disk beyond the point of data retrieval.
- Shocks unbalance the platter. They either vibrate vertically or horizontally. Vertical vibration causes a head crash and horizontal vibration leads to the read head unable to track properly. When the magnetised surface is intact, data can be retrieved from the platters by not requiring them to spin. The entire surface of the disk is scanned and data recovered. But this is an extremely time-consuming and expensive procedure.
- Successful data recovery is also dependent upon the type of drive. The hard drive after being assembled is conditioned to work in perfect coordination with the read write head and platters that are actually being used in the computer. So if a particular component is damaged it is not always possible to find an exact replacement. Even if the parts have the same component number replacement is not always a possibility.
- The electronic circuit board often poses problems. When proper matching circuit board is not available, it has to be laboriously soldered.
Whenever the computer user faces a problem it has to be ascertained whether the damage is physical or logical. Physical damages require the expert handling by data recovery companies and if criminal damage is suspected then Computer Forensics may be required.