Why mechanical failure causes HDD being undetectable by bios or OS ?
Could someone please explain why in the case of *mechanical* failure HD
becomes sometimes undetected by BIOS and/or the operating system (e.g. win xp
If it was an electronic failure then such behaviour would be obious, but why
the same happens with some mechanical failures? When electronics is working in
my opinion it still should be detected by bios and/or the system (win xp or
linux), but often it is not.
I could recover about 80% of the data from my HDD (which apparently has a
mechanical failure - plates spin up and down, heads create bad noises) if only
the disk could be seen by the system all the time. But often during copying of
the data heads hit with a loud sound so badly that sometimes even the plates
stop rotating, and the disk then dissapears from the system. It is then very
difficult to make it detectable by the system again, sometimes the sytem can
detect it but only after several minutes of copying it freezes and then
Recently, I was unlucky, and even after several dozens of retries it's still
undetectable by the system.
Could you please advice what to do to make the disk detectable by the system
all the time?
What causes that it is not detectable although the failure is in mechanics not
BTW, if someone has the same disk model (Quantum Fireball ST64A011), please
let me know.