Hallo
one friend just plug the 4 pin power connector in the wrong way to her
hard disc.
It seems that the part which is used to protect the over voltage has
been burn-off.
I am gonna change the part which is "physical" broken and back up her
data.
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?
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.
On Mon, 17 Nov 2008 13:00:54 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:
>one friend just plug the 4 pin power connector in the wrong way to her
>hard disc.
>It seems that the part which is used to protect the over voltage has
>been burn-off.
>I am gonna change the part which is "physical" broken and back up her
>data.
>
>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?
Tricky business :-)
But on the bright side: If the part is indeed an overvoltage
protection device (which I doubt) going into 'permanent
protection mode' (i.e. short circuit) you could simply cut one of
it's wires.
As the drive is likely to be toasted anyway, this will either get
the drive working for a while or will otherwise do no further
harm.
On 18 Nov., 21:39, bok...@zonnet.nl (Gerard Bok) wrote:
> On Mon, 17 Nov 2008 13:00:54 -0800 (PST), "borat.gunter"
>
>
>
> <borat.gun...@googlemail.com> wrote:
> >one friend just plug the 4 pin power connector in the wrong way to her
> >hard disc.
> >It seems that the part which is used to protect the over voltage has
> >been burn-off.
> >I am gonna change the part which is "physical" broken and back up her
> >data.
>
> >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?
>
> Tricky business :-)
> But on the bright side: If the part is indeed an overvoltage
> protection device (which I doubt) going into 'permanent
> protection mode' (i.e. short circuit) you could simply cut one of
> it's wires.
> As the drive is likely to be toasted anyway, this will either get
> the drive working for a while or will otherwise do no further
> harm.
>
> --
> Kind regards,
> Gerard Bok
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 Tue, 18 Nov 2008 13:23:57 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:
>On 18 Nov., 21:39, bok...@zonnet.nl (Gerard Bok) wrote:
>> On Mon, 17 Nov 2008 13:00:54 -0800 (PST), "borat.gunter"
>> <borat.gun...@googlemail.com> wrote:
>> >one friend just plug the 4 pin power connector in the wrong way to her
>> >hard disc.
>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.
The principle is easy.
You have your +12 volt which is used for the motor only.
(Correct me if I'm wrong.) You won't hurt the motor circuit with
5 volt.
And you have your +5 volt for the logic. 'Logic' are the parts
that will usually explode rather spectacular if exposed to
voltages over 7 or 8 volt.
>I was thinking that the burn component were a fuse-like thing, which
>would be sacrificed in order to protect the parts behind.
That would make sense. Were it not that such a circuit would add
a dime to the manufacturing costs :-)
>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.
It would require both a fuse and a pretty big zener type diode.
Practically, this goes by the name crowbar and is implemented
using a fuse, a zener diode and a thyristor. Common in a PSU but
I've never seen them on harddisk controller boards.
>Any schematic reference would be really helpful.
Sorry. The most recent schematics on harddisk I have at hand are
probably 20+ years old.
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.
I have been busy. Now i wanna give a feedback to my previous question.
After reading you guys's suggestion. I decided to resolder the diode
which came from another new harddisc.
And it works out, which means the diode does protect the circuit
afterward, of course my friend has to sacrifice her new harddisc.
I have no idea what kind of type diode can be used. I suggested her to
look after a used one on ebay, so that her new one can be "repaired"
as well.
For now she is more than happy for having her baby photos again.
Thanks for your guys.
On 19 Nov., 01:10, kony <s...@spam.com> wrote:
> On Tue, 18 Nov 2008 13:23:57 -0800 (PST), "borat.gunter"
>
> <borat.gun...@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.
On Thu, 18 Dec 2008 07:47:39 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:
>Hello folks,
>
>I have been busy. Now i wanna give a feedback to my previous question.
>
>After reading you guys's suggestion. I decided to resolder the diode
>which came from another new harddisc.
>
>And it works out, which means the diode does protect the circuit
>afterward, of course my friend has to sacrifice her new harddisc.
>
>I have no idea what kind of type diode can be used. I suggested her to
>look after a used one on ebay, so that her new one can be "repaired"
>as well.
>For now she is more than happy for having her baby photos again.
>Thanks for your guys.
>
What specs are required for the diode depends on where it
is, in which subcircuit. If it were only polarity
protection on the power input, just about anything that's
the right physical size would work.
if it's in a switching regulation circuit, an ultrafast
silicon or schotty would be desired.
Schottky would be the best, most compatible choice, since
the main limit in this use for schottky is their lower
voltage but there is no high voltage on a hard drive that
would exceed the typical schottky voltage ranges.
Therefore, pick a schottky that is the same physical size so
it can be soldered onto the pads where the old one was, and
rated for over 12V which almost all are. With that size and
the lowest voltage you can find above 12V, it should also be
capable of enough current.
Potential sources for it include Digikey, Mouser, Allied
Electronics, Newark, et al. Digikey would be among the most
expensive since they have a minimum order fee which AFAIK is
still $5, more than double what the diode probably costs.
You might also find one at an electronics surplus 'site
somewhere but not so much with surface mount parts. You
might also ask at a local electronics repair shop as they
might have some. Places like Radio Shack are not likely to
have any.
here comes the question again. What I am pretty sure is i need a 5v
not a 12v diode. plus SOD as a must.
But other parameters I have no idea at all. I have no idea how big the
current flow to the subcircuit. and
how big should the capacitor be for esd reason.
Is there anyway that I can learn how to decide this. How does the pcb
designer make their choice? It has to be some rules, or tutorials. or
we just know it.
Best
Borat
On 18 Dez., 17:20, kony <s...@spam.com> wrote:
> On Thu, 18 Dec 2008 07:47:39 -0800 (PST), "borat.gunter"
>
>
>
> <borat.gun...@googlemail.com> wrote:
> >Hello folks,
>
> >I have been busy. Now i wanna give a feedback to my previous question.
>
> >After reading you guys's suggestion. I decided to resolder the diode
> >which came from another new harddisc.
>
> >And it works out, which means the diode does protect the circuit
> >afterward, of course my friend has to sacrifice her new harddisc.
>
> >I have no idea what kind of type diode can be used. I suggested her to
> >look after a used one on ebay, so that her new one can be "repaired"
> >as well.
> >For now she is more than happy for having her baby photos again.
> >Thanks for your guys.
>
> What specs are required for the diode depends on where it
> is, in which subcircuit. *If it were only polarity
> protection on the power input, just about anything that's
> the right physical size would work.
>
> if it's in a switching regulation circuit, an ultrafast
> silicon or schotty would be desired.
>
> Schottky would be the best, most compatible choice, since
> the main limit in this use for schottky is their lower
> voltage but there is no high voltage on a hard drive that
> would exceed the typical schottky voltage ranges.
> Therefore, pick a schottky that is the same physical size so
> it can be soldered onto the pads where the old one was, and
> rated for over 12V which almost all are. *With that size and
> the lowest voltage you can find above 12V, it should also be
> capable of enough current.
>
> Potential sources for it include Digikey, Mouser, Allied
> Electronics, Newark, et al. *Digikey would be among the most
> expensive since they have a minimum order fee which AFAIK is
> still $5, more than double what the diode probably costs.
> You might also find one at an electronics surplus 'site
> somewhere but not so much with surface mount parts. *You
> might also ask at a local electronics repair shop as they
> might have some. *Places like Radio Shack are not likely to
> have any.
On Thu, 18 Dec 2008 13:34:09 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:
>Hey Kony,
>
>I really appreciate your answers and advices.
>I uploaded 2 pictures of the 2 harddiscs, in case somebody wanna take
>a look.
>http://picasaweb.google.de/borat.gunter/Harddisc#
>
>I just looked after "schottky diode 5v'" at digikey.com.
>http://search.digikey.com/scripts/Dk...hottky%20diode
>
>here comes the question again. What I am pretty sure is i need a 5v
>not a 12v diode. plus SOD as a must.
>But other parameters I have no idea at all. I have no idea how big the
>current flow to the subcircuit. and
>how big should the capacitor be for esd reason.
>
>Is there anyway that I can learn how to decide this. How does the pcb
>designer make their choice? It has to be some rules, or tutorials. or
>we just know it.
>
>Best
>
>Borat
A diode's voltage rating is the maximum it is guaranteed to
withstand. Unless it is a zener diode you want the voltage
rating to be above the voltage at that point in the circuit.
By knowing the circuit, that is how they chose the component
value to use.
Since you have the diode from another hard drive circuit
board, get out a magnifying glass and read the codes off of
it and either go to the manufacturer's website or search for
them here to find out it's specs: http://alldatasheet.com/
yeh.
that was what i did at the beginning,
VU GP804 AE is on the package.
but I didnt find anything similar to this decription.
That is the reason why I was digging deeply in order to figure out
which component it is.
Otherwise it would be too simple. ;-)
On 19 Dez., 01:41, kony <s...@spam.com> wrote:
> On Thu, 18 Dec 2008 13:34:09 -0800 (PST), "borat.gunter"
>
>
>
> <borat.gun...@googlemail.com> wrote:
> >Hey Kony,
>
> >I really appreciate your answers and advices.
> >I uploaded 2 pictures of the 2 harddiscs, in case somebody wanna take
> >a look.
> >http://picasaweb.google.de/borat.gunter/Harddisc#
>
> >I just looked after "schottky diode 5v'" at digikey.com.
> >http://search.digikey.com/scripts/Dk...t=1376383&keyw....
>
> >here comes the question again. What I am pretty sure is i need a 5v
> >not a 12v diode. plus SOD as a must.
> >But other parameters I have no idea at all. I have no idea how big the
> >current flow to the subcircuit. and
> >how big should the capacitor be for esd reason.
>
> >Is there anyway that I can learn how to decide this. How does the pcb
> >designer make their choice? It has to be some rules, or tutorials. or
> >we just know it.
>
> >Best
>
> >Borat
>
> A diode's voltage rating is the maximum it is guaranteed to
> withstand. *Unless it is a zener diode you want the voltage
> rating to be above the voltage at that point in the circuit.
> By knowing the circuit, that is how they chose the component
> value to use.
>
> Since you have the diode from another hard drive circuit
> board, get out a magnifying glass and read the codes off of
> it and either go to the manufacturer's website or search for
> them here to find out it's specs:http://alldatasheet.com/
On 19 Dez., 01:41, kony <s...@spam.com> wrote:
> On Thu, 18 Dec 2008 13:34:09 -0800 (PST), "borat.gunter"
>
>
>
> <borat.gun...@googlemail.com> wrote:
> >Hey Kony,
>
> >I really appreciate your answers and advices.
> >I uploaded 2 pictures of the 2 harddiscs, in case somebody wanna take
> >a look.
> >http://picasaweb.google.de/borat.gunter/Harddisc#
>
> >I just looked after "schottky diode 5v'" at digikey.com.
> >http://search.digikey.com/scripts/Dk...t=1376383&keyw....
>
> >here comes the question again. What I am pretty sure is i need a 5v
> >not a 12v diode. plus SOD as a must.
> >But other parameters I have no idea at all. I have no idea how big the
> >current flow to the subcircuit. and
> >how big should the capacitor be for esd reason.
>
> >Is there anyway that I can learn how to decide this. How does the pcb
> >designer make their choice? It has to be some rules, or tutorials. or
> >we just know it.
>
> >Best
>
> >Borat
>
> A diode's voltage rating is the maximum it is guaranteed to
> withstand. *Unless it is a zener diode you want the voltage
> rating to be above the voltage at that point in the circuit.
> By knowing the circuit, that is how they chose the component
> value to use.
>
> Since you have the diode from another hard drive circuit
> board, get out a magnifying glass and read the codes off of
> it and either go to the manufacturer's website or search for
> them here to find out it's specs:http://alldatasheet.com/
I did it first. But the info on the package was not so useful.
it is "VU gp802 AE"
I googled around, found nothing about this
On Fri, 19 Dec 2008 06:07:52 -0800 (PST), "borat.gunter"
<borat.gunter@googlemail.com> wrote:
>> Since you have the diode from another hard drive circuit
>> board, get out a magnifying glass and read the codes off of
>> it and either go to the manufacturer's website or search for
>> them here to find out it's specs:http://alldatasheet.com/
>
>I did it first. But the info on the package was not so useful.
>it is "VU gp802 AE"
>I googled around, found nothing about this
Use an ultrafast silcon, 8 amp rated diode. You'll have to
measure it's size and compare that to what digikey shows in
it's search fields. Voltage rating doesn't matter, they'll
all be rated higher than the 5V, even 12V, present on this
point in the circuit.
Schematic of Hard disc pcb 
Linear Mode
