When your computer is powered up the motherboard undertakes a Power-on Self-Test (POST) in order that the BIOS (Basic Input/Output System) can identify all the attached components. Should the hard disk drive not be identified, it may be due to a physical failure of the drive controller board or another component. Should the drive be detected but show a different capacity or identification string, it clearly indicates a failure on the controller board, which will require data recovery.
Hard Drive Not Found by BIOS
The first action is to check that the data and power cables are checked as well as different ports on the motherboard or mass storage controller card. It is important that proper anti-static precautions are taken before you open your computer, as failure to do so may cause additional component failures. In rare cases this will resolve the problem and the hard disk drive will reappear.
Should the hard disk drive still fail to be found by the BIOS, it is most likely that a failure has occurred on the drive controller board. In this case the computer should be powered down, as repeated attempts at booting the computer may potentially cause further damage, which could make the data recovery more complex than necessary.
Device Identification is Different in BIOS
Following the failure of the controller board, many drive models, such as Western Digital hard disk drives will be detected by the BIOS with a default device identifier string such as “WDC ROM MODEL-HAWK.” In the majority of cases when this occurs, the data stored on the disk is undamaged and be retrieved through data recovery. Should you see this type of identification string, you should power the computer down as repeated attempts to boot the computer will not resolve the failure, and may potentially compound the problem further.
Hard Drive Controller Board Failures
The hard disk drive controller board is a multifunction component, which must undertake several tasks correctly in order for the disk to operate properly. These functions include acting as the input/output interface between the hard disk and the host computer, controlling the read/write heads, applying the correct power to the motor, in order that it spins at the correct speed. Should any of these functions not be performed correctly it may lead to erratic behaviour, which if allowed to continue unchecked, could lead to further problems and even data corruption.
Damaged due to a power surge or from a build-up of heat are the most common hard disk drive controller board failure mechanisms. The damage resulting from these can cause a failure of any component, such as for example the firmware, power regulator and maintenance area. Once a failure occurs on the hard drive controller board, the data is rendered inaccessible, and attempts to reboot the computer may result in additional damage. The computer should therefore be powered down and the failed drive sent for professional data recovery.