Such failures usually make the disk unrecognizable in BIOS system. Service area is the zone that contains microcode/firmware of the disk. This zone usually represents cylinders on the platter of the disk which are specifically assigned to microcode. The other part if microcode is located on PCB. Disks, when encountering these problems, usually register to system with fabric aliases.
- Maxtor : N40P, ATHENA, CALYPSO, ROMULUS, SABRE
- Seagate: Disk registers with system BIOS, but blocks the system or reports disk size as 0GB.
- Westen Digital: WD-ROM-0GB
You should bear in mind, If there is no PCB or mechanical failure (HDA), but the disc is still undetectable in BIOS, the most common cause is a failure of parts or whole of service area (UBA).
