Still looking for info on a J3U diode.

[Tim]

Well in case you missed the original post, this critter is on a DC
charger board mad by Ambit,(no help from them), in an Acer Notebook (no
help from them either). The board's part number is T62.120.C.01.

I can buy a replacement board, but seeing as the only problem sems to be
this diode, I'd like to fix it. The defective one is shorted, and an
identical one meters as a diode should. I believe this component to be
used as a clamp for DC spikes from a coil.

The component markings are simply a J3U with a smaller 9N beneath that.
I believe the package type is SMC with the soldr tabs formed as "J"
under the part.

Any help would be greatly appreciated...

- Tim -

 

[legg]

On Mon, 13 Dec 2004 03:02:22 GMT, Tim <tim@tim.tim> wrote:

Well in case you missed the original post, this critter is on a DC
charger board mad by Ambit,(no help from them), in an Acer Notebook (no
help from them either). The board's part number is T62.120.C.01.

I can buy a replacement board, but seeing as the only problem sems to be
this diode, I'd like to fix it. The defective one is shorted, and an
identical one meters as a diode should. I believe this component to be
used as a clamp for DC spikes from a coil.

The component markings are simply a J3U with a smaller 9N beneath that.
I believe the package type is SMC with the soldr tabs formed as "J"
under the part.

Have you measured these parts out-of-circuit, yet?

RL

 

[legg]

On Mon, 13 Dec 2004 16:37:22 GMT, Tim <tim@tim.tim> wrote:

Man I been so busy, I lost all track of what I was doing. The defective
one, of course, is dead shorted whether in circuit or out. The other
diode reads as a diode should. A zener should read as near shorted, even
tho it is good right? or is it open, I'm just not sure how a Transil
type device would read, as the only time I had one to test, it read as a
regular diode. I really don't want to stress test the good one, as it
would fail to shorted if it is indeed a Transil device.

I have also seen a different revision of this board with the same part
number, but it had different type of diodes on it, but I still could not
get any info about them, as the supplier did not wish to give out any
info.

What was the forward voltage drop of the good part, when tested?(what
did your meter read)

RL

 

[legg]

On Mon, 13 Dec 2004 16:37:22 GMT, Tim <tim@tim.tim> wrote:

I have also seen a different revision of this board with the same part
number, but it had different type of diodes on it, but I still could not
get any info about them, as the supplier did not wish to give out any
info.

Any designation on the different type?

RL

 

[Tim]

Correction the voltage to ground is 17 volts from either side of the
good diode, but is only 1 of the pads where the shorted one was mounted
(the cathode (band) end) has the 17 volts on it. The drop across the
good diode a 10th of a volt no matter which way it is metered.

- Tim -

In article <MPG.1c281ecb230835429896af@allnews.nbnet.nb.ca>, tim@tim.tim
says...

I read about 20 volts (very stable) across the good diode, and across
where the shorted one used to be. I can't run the notebook for very
long, only about 20 secs or so, because I have to remove the heatsink
plate that keeps the CPU cool to meter the board.

The pic I saw of the other version did not show any part id on it's
diodes. It seems to identical except for the 2 diodes in question. They
are located beside the coil with the 220 on it, 1 vertical on the coil's
left side and 1 horizontal under the same coil. Here's the url of the
other version;

http://www.pchub.com/uph/catf/BigPicture.aspx?iid=10901&PhotPath=
6322326247034375002_ACPOINAACTM515T.jpg

Thanks,

- Tim -

In article <399sr0dc528s25pq62nc4ash9h59libqdj@4ax.com>,
legg@nospam.magma.ca says...
On Mon, 13 Dec 2004 16:37:22 GMT, Tim <tim@tim.tim> wrote:

I have also seen a different revision of this board with the same part
number, but it had different type of diodes on it, but I still could not
get any info about them, as the supplier did not wish to give out any
info.

Any designation on the different type?

RL

 

[Tim]

Man I been so busy, I lost all track of what I was doing. The defective
one, of course, is dead shorted whether in circuit or out. The other
diode reads as a diode should. A zener should read as near shorted, even
tho it is good right? or is it open, I'm just not sure how a Transil
type device would read, as the only time I had one to test, it read as a
regular diode. I really don't want to stress test the good one, as it
would fail to shorted if it is indeed a Transil device.

I have also seen a different revision of this board with the same part
number, but it had different type of diodes on it, but I still could not
get any info about them, as the supplier did not wish to give out any
info.

- Tim -

In article <ebuqr0h3aqmf39csov8pimr4iieb0e1bso@4ax.com>,
legg@nospam.magma.ca says...

On Mon, 13 Dec 2004 03:02:22 GMT, Tim <tim@tim.tim> wrote:

Well in case you missed the original post, this critter is on a DC
charger board mad by Ambit,(no help from them), in an Acer Notebook (no
help from them either). The board's part number is T62.120.C.01.

I can buy a replacement board, but seeing as the only problem sems to be
this diode, I'd like to fix it. The defective one is shorted, and an
identical one meters as a diode should. I believe this component to be
used as a clamp for DC spikes from a coil.

The component markings are simply a J3U with a smaller 9N beneath that.
I believe the package type is SMC with the soldr tabs formed as "J"
under the part.

Have you measured these parts out-of-circuit, yet?

RL

 

[Tim]

I read about 20 volts (very stable) across the good diode, and across
where the shorted one used to be. I can't run the notebook for very
long, only about 20 secs or so, because I have to remove the heatsink
plate that keeps the CPU cool to meter the board.

The pic I saw of the other version did not show any part id on it's
diodes. It seems to identical except for the 2 diodes in question. They
are located beside the coil with the 220 on it, 1 vertical on the coil's
left side and 1 horizontal under the same coil. Here's the url of the
other version;

http://www.pchub.com/uph/catf/BigPicture.aspx?iid=10901&PhotPath=
6322326247034375002_ACPOINAACTM515T.jpg

Thanks,

- Tim -

In article <399sr0dc528s25pq62nc4ash9h59libqdj@4ax.com>,
legg@nospam.magma.ca says...

On Mon, 13 Dec 2004 16:37:22 GMT, Tim <tim@tim.tim> wrote:

I have also seen a different revision of this board with the same part
number, but it had different type of diodes on it, but I still could not
get any info about them, as the supplier did not wish to give out any
info.

Any designation on the different type?

RL

 

[legg]

On Tue, 14 Dec 2004 01:49:35 GMT, Tim <tim@tim.tim> wrote:

I read about 20 volts (very stable) across the good diode, and across
where the shorted one used to be. I can't run the notebook for very
long, only about 20 secs or so, because I have to remove the heatsink
plate that keeps the CPU cool to meter the board.

The pic I saw of the other version did not show any part id on it's
diodes. It seems to identical except for the 2 diodes in question. They
are located beside the coil with the 220 on it, 1 vertical on the coil's
left side and 1 horizontal under the same coil. Here's the url of the
other version;

http://www.pchub.com/uph/catf/BigPicture.aspx?iid=10901&PhotPath=
6322326247034375002_ACPOINAACTM515T.jpg

This will be a schottky rectifier. It will be 30V or less in a laptop
converter. Most mfrs don't go above 3A in this body size. Those that
do intend them for use in low voltage orring situations (below 15V),
not in rectifiers or in chargers.

IR - MBRS340 or 30BQ040

Diodes Inc - B330, B340, SK33, SK34, B530, B540

ST Micro - STPS340S

ON - MBRS330, MBRS340

All are in the Digikey catalog, from US$1.06 to US$4.93 each,
depending on mfr.

RL

 

[Tim]

OK, Thanks, I will source out one of the items you listed and we'll see
if the notebook survives. I am sure it is ok, it does run without the
shorted diode in place.

Thanks again for all your help leggs

- Tim -


In article <lcpur0hhtrlql00vq6duad0nqav9u6vdon@4ax.com>,
legg@nospam.magma.ca says...

On Tue, 14 Dec 2004 01:49:35 GMT, Tim <tim@tim.tim> wrote:

I read about 20 volts (very stable) across the good diode, and across
where the shorted one used to be. I can't run the notebook for very
long, only about 20 secs or so, because I have to remove the heatsink
plate that keeps the CPU cool to meter the board.

The pic I saw of the other version did not show any part id on it's
diodes. It seems to identical except for the 2 diodes in question. They
are located beside the coil with the 220 on it, 1 vertical on the coil's
left side and 1 horizontal under the same coil. Here's the url of the
other version;

http://www.pchub.com/uph/catf/BigPicture.aspx?iid=10901&PhotPath=
6322326247034375002_ACPOINAACTM515T.jpg


This will be a schottky rectifier. It will be 30V or less in a laptop
converter. Most mfrs don't go above 3A in this body size. Those that
do intend them for use in low voltage orring situations (below 15V),
not in rectifiers or in chargers.

IR - MBRS340 or 30BQ040

Diodes Inc - B330, B340, SK33, SK34, B530, B540

ST Micro - STPS340S

ON - MBRS330, MBRS340

All are in the Digikey catalog, from US$1.06 to US$4.93 each,
depending on mfr.

RL