1. Firmware Corruption / Damage to the firmware zone Hard disk firmware is the information that is used by the computer that allows it to correctly interact with the hard disk. If the firmware of a hard disk becomes corrupted or unreadable the computer is often unable to correctly interact with the hard disk. Frequently the data on the disk is fully recoverable once the drive has been repaired and reprogrammed. 2. Electronic Failure Electronic failure usually relates to problems on the controller board of the actual hard disk. The computer may suffer a power spike or electrical surge that knocks out the controller board on the hard disk making it undetectable to the BIOS. Usually, the data on the hard disk has not suffered any damage and a 100% data recovery is possible.
