What causes a hard drive to be not recognized by the BIOS ..

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Did you use the diagnostics from the manufacturer? It may detect the drive
when the BIOS doesn't

The BIOS does an ATA Identify, which will fail if the drive firmware doesn't
load, or takes too long because of read retries. It also reads the MBR, but
that shouldn't prevent detection.

"Will Dormann" <wdormann@yahoo.com.invalid> wrote in message
news:WTCdc.6453$ng1.5196@fe2.columbus.rr.com...
> I took a look at a "dead" hard drive for a friend today. It's not being
> recognized by the BIOS anymore.
>
> Once or twice the drive was recognized OK, and during those times the
> diagnostic software I used indicated that the drive had a bad sector 0.
>
> Is the information that a drive presents to a computer's BIOS stored
> somewhere as data on the platters somewhere? (I was thinking that the
> information was in the firmware of the drive) Could this be a case
> where the drive developed enough bad sectors, and because they happen to
> be in the sector 0 area, it's not being recognized by the BIOS?
>

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

Will Dormann <wdormann@yahoo.com.invalid> wrote in message
news:WTCdc.6453$ng1.5196@fe2.columbus.rr.com...

> I took a look at a "dead" hard drive for a friend today.
> It's not being recognized by the BIOS anymore.

> Once or twice the drive was recognized OK, and during those times the
> diagnostic software I used indicated that the drive had a bad sector 0.

> Is the information that a drive presents to a computer's BIOS
> stored somewhere as data on the platters somewhere?

That varys with the drive. Some of the maxtors do fall back to
a different report when the drive cant read the platters anymore.

> (I was thinking that the information was in the firmware of the drive)

Yes, but not always all the information.

> Could this be a case where the drive developed enough
> bad sectors, and because they happen to be in the
> sector 0 area, it's not being recognized by the BIOS?

Its more likely in your case that the logic card has an
intermittent fault and thats why it sometimes responds
to the ATA identify command issued by the bios and
sometimes it doesnt and so doesnt get listed by the bios.

You can also get that effect with a bad cable too.