Hard Disk Failure:

Hard Disk Failure occurs when a hard disk drive malfunctions and the accumulate data cannot be accessed. It may happen in the course of normal operation due to an internal or external factor.

Disk failure varies and the most common is "Head Crash" where the internal read and write head of a device touches a platter or magnetic storage surface often grinding away the magnetic surface. Head hover just micrometers from the platters plane which makes such collision a common one.

This sort of crash usually invites severe data loss and unprofessional data recovery attempts results further damage to the remaining data.

Hard drive also includes other controller electronics i.e., semiconductors, valves or electronic circuits, and major components such as Platters, Spindle Motor and Head Actuator. Failure of any these devices may cause a hard disk failure.

Factors causes disk failure are numerous, yet most common are power surges, voltage fluctuations, electronic malfunction, physical shock, wear and tear, corrosion, exposure to high magnetic waves, sharp impact, high temperature exposure etc.

The phenomena of hard disk failure is raising higher and higher; as to increase the read and write speed, today we have latest hard disk rotating amazingly faster and this immense revolving speed generates massive centrifugal force, a single adverse cause in the course of normal operation can cause severe hard disk failure. 

Hard Disk Data Recovery:

Hard disk data recovery is the process of recovering the trapped data from the damage hard disk device, when it can not be accessed in normal circumstance.

Several Techniques are used to retrieving data from damaged hard disk and techniques vary accordingly. It can be done by moving disk drive to a working CPU, or may have to open the disk drive and replace parts such as read/write heads, arms and chips and sometime the platters have to be removed and placed into another drive.

Physical damage can not be repaired by the general users, as it requires clean and dust free lab environment, in addition proper hardware and technical expertise; where under microscopic examination with proper tool and techniques, the damage drive is put on to observation for data salvaging.