On Tue, 18 Nov 2008 13:23:57 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:


>I have asked my friend to take a picture. will follow up
>But I am curious about the schematic part of such circuit. How does
>the subcirciut work. No only in oder to fix it, more like the
>principle.
>I was thinking that the burn component were a fuse-like thing, which
>would be sacrificed in order to protect the parts behind.
>
>After discussing with my co-worker I think the hardware vendor would
>pay more attention or effort on fuse-like component, since the
>connector alone is really hard enough to connecte in the reverse way
>which my friend did. I can't do that on my pc ;-(
>
>Any schematic reference would be really helpful.
>Thanks

On a hard drive, such a diode would typically be used right
after the power socket for polarity protection, or in a
power regulation circuit along with a transitor(s) and
inductor. Either way, "IF" the diode has failed it is
usually a sign that far too much current has passed to parts
beyond it in the circuit.

If you don't have the proper physical size or surface
mounted replacement diode, you could probably find something
with leads at a local electronics shop or repair center, or
cannibalize a randon switching PSU (like a wall wart brick
style) to get a suitable diode with leads and tack it down,
soldered onto the PCB temporarily just to see if the drive
works at all... but I would hook it up alone to a worthless
old computer power supply, not in a valuable system and not
with the data cable connected for the first attempt to see
if it starts smoking or popping chips... the PSU itself may
not even be able to turn on or really I mean stay on because
of the drive being too badly damaged.