The first action your computer undertakes when it switched on is the Power-on self-test (POST) during which the BIOS (Basic Input/Output System) will identify all the attached components, including add-on cards and installed hard disk drives. When a failure of a hard disk drive occurs one of the most commonly seen messages which appears on the screen will be “Drive not recognised” or similar.
When this occurs, there is a physical problem with the drive, often due to a failure of the drive controller. On some drives, it may still detect a hard disk drive, but report back with a different identification string and a reduced capacity. Such failures require data recovery by a professional data recovery company, such as DiskEng, who have the expertise and knowledge required to recovery your fails.
BIOS Fails to See Hard Drive
Once the obvious potential issues have been eliminated, such a cable fault and plugging it into a different socket, it is almost certain that the fault is present on the drive controller board. It is important that if you open the case, that proper anti-static precautions are taken to avoid damaging the sensitive electronics.
Even though the drive is not appearing in the BIOS, repeated attempts could potentially cause further damage to occur to the hard disk drive. It is therefore important not to prolong any fault diagnosis, as any additional damage could make the data recovery process more complicated.
Hard Drive Appears as Different Device in BIOS
Many Western Digital hard disks use an initial drive identification string, such as “WDC ROM MODEL-HAWK” not seen during normal operation. However, when this string or a similar one appears during boot time or in the BIOS, it indicates a failure of the drive controller board.
When such a failure has occurred, no amount of rebooting or swapping of cables will bring the drive back to its normal operating conditions. Each reboot can potentially cause further damage, so it is essential to power the computer off and send the drive for data recovery.
Failure of Hard Drive Controller Board
The importance of the hard drive controller board is often overlooked, but serves several important functions, which all be performed correctly for the disk to remain operational. It is responsible for controlling the speed at which the platters spin, controls the positioning of the read/write heads and acts as the input/output interface between the drive and the host computer.
If it fails in any of these tasks, the drive may either completely fail or behave erratically. Damage to the controller board is most commonly caused through heat build-up or power surges, both of which can damage any component, such as the power regulator or firmware. The data will then become inaccessible, requiring professional data recovery services to gain access the files.
