Help ID an SMD part J3U 9N (Still Looking)

[Tim]

Hi, I have been trying to source out info on this SMD part for several
days now. It looks like a diode or transil device use in the circuit.
The device I have is dead shorted, and another identical device reads as
a diode. It is marked J3U with a 9N below that. Searches on google and
yahoo did not turn up any useful info. I have checked an smd resource
and found simliar device numbers but they where caps.

Or even a schematic of an Acer Travelmate 514 dc convertor board would
give me the info I need, I can't find that either.

Any help would be greatly appeciated.

Thanks

- Tim -

(email is fake, please reply in group)(damn spammers)

 

[legg]

On Fri, 03 Dec 2004 23:11:32 GMT, Tim <tim@tim.tim> wrote:

Hi, I have been trying to source out info on this SMD part for several
days now. It looks like a diode or transil device use in the circuit.
The device I have is dead shorted, and another identical device reads as
a diode. It is marked J3U with a 9N below that. Searches on google and
yahoo did not turn up any useful info. I have checked an smd resource
and found simliar device numbers but they where caps.

Or even a schematic of an Acer Travelmate 514 dc convertor board would
give me the info I need, I can't find that either.

Any help would be greatly appeciated.

Body size is an important part of SMD identification. You don't
mention it.

http://www.marsport.demon.co.uk/smd/smdcode.htm


9N PLVA2662A Phi A SOT23 dual ca 6.2V reg diode
9N CMDZ2L2 CSC I SOD323 zener 250mW Iz 0.5mA 2.2V
J3 ZC831 Zet C SOT23 ZC821
J3 MMSZ5248 Vis I SOD123 zener 300mW 5% 18V
J3 CMOZ20V CSC I SOD523 zener 350mW 5% 20V

RL

 

[Tim]

In article <h732r0dblaulnfihkjmnv0n1ef2djqf7r5@4ax.com>,
legg@nospam.magma.ca says...

On Fri, 03 Dec 2004 23:11:32 GMT, Tim <tim@tim.tim> wrote:

Hi, I have been trying to source out info on this SMD part for several
days now. It looks like a diode or transil device use in the circuit.
The device I have is dead shorted, and another identical device reads as
a diode. It is marked J3U with a 9N below that. Searches on google and
yahoo did not turn up any useful info. I have checked an smd resource
and found simliar device numbers but they where caps.

Or even a schematic of an Acer Travelmate 514 dc convertor board would
give me the info I need, I can't find that either.

Any help would be greatly appeciated.

Body size is an important part of SMD identification. You don't
mention it.

http://www.marsport.demon.co.uk/smd/smdcode.htm


9N PLVA2662A Phi A SOT23 dual ca 6.2V reg diode
9N CMDZ2L2 CSC I SOD323 zener 250mW Iz 0.5mA 2.2V
J3 ZC831 Zet C SOT23 ZC821
J3 MMSZ5248 Vis I SOD123 zener 300mW 5% 18V
J3 CMOZ20V CSC I SOD523 zener 350mW 5% 20V

RL


I believe it is an "I". I appreciate the link and the info. I have seen

this page before (or a clone of it).

I guess the U at the end means something else? I figured the U would be
extra info, and the 9N would be a date code as it is located under the
J3U.

The device really does not match anything listed. This one is about 7 mm
long and 4mm wide. It is similiar to the SOD series, but a lot bigger.

Thanks,

- Tim -

 

[Tim]

In article <foj2r019oa9mg48qeajhctuhufhtsoi8gj@4ax.com>,
legg@nospam.magma.ca says...

On Sat, 04 Dec 2004 03:51:54 GMT, Tim <tim@tim.tim> wrote:

http://www.semtech.com/pdf/sdxx.pdf

Semtech shows a 5U and 6U marking codes for smaller-bodied (SOD323 is
1.2mm wide) smd tvs devices.

DO214AB is SMC >4mm W
DO214AA is SMB <4mm W
DO214AC is SMA <3mm W

Fagor offers tvs @10V in DO214AA marked PN.

http://www.fagorelectronica.com/semi/pdf/producto/p6smb.pdf

Addendum. I believe this to be aa SMC style case (j tabs), but it is
narrower than the spec as it is only 4mm instead of 5mm.

If that helps any.

- Tim -


Still not the same critter. It seems that the ones at the first link do

not come as SMC style, with the pins folded under, but the ones listed
at the second link are close, just shorter.

This thing is in an Acer notebook too, so I'm having a real hard time
getting info on the board itself.

Geez a simple problem with an easy fix, all I gotta do is get one little
part. Sounds simple huh?

Thanks

- Tim -

 

[Tim]

In article <m2f6r05i1ls56ki5e20jbbb5fou5858fe8@4ax.com>,
legg@nospam.magma.ca says...

On Sat, 04 Dec 2004 18:45:29 GMT, Tim <tim@tim.tim> wrote:



Still not the same critter. It seems that the ones at the first link do
not come as SMC style, with the pins folded under, but the ones listed
at the second link are close, just shorter.

This thing is in an Acer notebook too, so I'm having a real hard time
getting info on the board itself.

Geez a simple problem with an easy fix, all I gotta do is get one little
part. Sounds simple huh?

I'd test the other, still-functioning part. You indicated that it
seemed to measure out as a diode, which rules out a bipolar tvs.

This could tell you if it's a discrete schottky, with a lower Vf, or
if it has a breakdown voltage characteristic of a tvs.

If it's a tvs, simply removing it is the first step in restoring basic
circuit function. If its a rectifier, a fair replacement shoudn't be
hard to get from Digikey or a similar source.

Acer seems to offer a fair network of agents willing to supply
replacement subassemblies. The model is also not rare, so perhaps a
scrapped unit is out there somewhere. As they no longer do their own
manufacturing, they may be unable to tell you the exact source for the
actual part, even if it was their policy to do so.

RL

I did contact Ambit, the manufacturer. And ya I can buy another DC
charger board for 55 bucks, but this seems like I should be able to fix
it myself. I did actually power up the board and found that both diodes
have about 20 volts across them. The bad one is dead shorted, and it
looks like the diodes are used to clamp voltages from a coil assembly. I
just want to get this puppie going without jeopardising the cicuit by
simply removing the diode.

- Tim -

 

[legg]

On Sun, 05 Dec 2004 23:50:01 GMT, Tim <tim@tim.tim> wrote:

I did contact Ambit, the manufacturer. And ya I can buy another DC
charger board for 55 bucks, but this seems like I should be able to fix
it myself. I did actually power up the board and found that both diodes
have about 20 volts across them. The bad one is dead shorted, and it
looks like the diodes are used to clamp voltages from a coil assembly. I
just want to get this puppie going without jeopardising the cicuit by
simply removing the diode.

20V across a short? Unlikely.

Desolder both and characterize.

Measure also the vacant locations. Rectifiers contacting a winding
that is grounded will give odd static readings in situ, due to
continuity through the winding. They may both be ok.

RL