On Mon, 17 Nov 2008 13:00:54 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:

>Hallo
>one friend just plug the 4 pin power connector in the wrong way to her
>hard disc.

She must have tried very hard to do this, since the power
connector is keyed and should not easily be inserted
backwards.


>It seems that the part which is used to protect the over voltage has
>been burn-off.

I suspect there is no overvoltage protection, that the
damaged components are related to some other function.


>I am gonna change the part which is "physical" broken and back up her
>data.

Your best bet would be to find a controller board from the
same drive, a board with even the same bios, and swap the
entire board.


>
>i wrote down the label on the component as
>AE VU
>GP804
>it has only 2 pins.
>
>I googled around, did not find the part datasheet.
>has anyone idea or reference of the schematic which is used for the
>hard dics pcb power protection?

When 12V was placed on the 5V subcircuits, it probably
caused overcurrent that damaged those components. The GP804
is probably a fast recovery rectifier (diode) which, if it
has actually failed (which you can test with a multimeter)
it would be because a downstream part consumed enough
current that the diode failed as a result, that the
downstream part(s) are also most likely damaged.

In other words you could try replacing this 8 amp fast
recovery diode with another one but it probably won't solve
the problem. If you replace the diode it need not be the
same exact GP804 part number, any fast recovery 8A silicon
diode with the same package size should work, since they're
all rated for higher voltage than would be present on a hard
drive.

If you made a high resolution scan of the hard drive PCB,
indicated on the picture which component it is, compressed
into JPG to reduce filesize, and posted it on an image
sharing site and linked to it here, someone might be able to
confirm my suspicion that it's a diode.