Identity a SOT-23 transistor marked MO5 or M05

Jonathan Schneider

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Dec 17, 2008, 4:59:10 PM12/17/08

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I'm fixing a laptop and am trying to identify a transistor which I
believe may be popped. Well I assume that's what it is. It has all
three legs connected.

It is SOT-23 and marked MO5 or could be M05 (letter Oh or digit zero).

There are a couple of others onboard and I believe it's part of the
power supply.

Any ideas ?

Thanks,

Jon

Jonathan Schneider

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Dec 17, 2008, 5:25:13 PM12/17/08

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Best guess is not a tranny but a dual zener (like part WOST05C) with
common anodes on the middle pin. Probing others onboard adds credence
to this though I'm very much open to suggestions.

Jon

Michael A. Terrell

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Dec 17, 2008, 8:26:41 PM12/17/08

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They generally use code numbers, not part of the actual number. There
are a couple databses on line like this one to help identify SMD semis.

http://www.marsport.org.uk/smd/mainframe.htm

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Franc Zabkar

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Dec 17, 2008, 9:29:38 PM12/17/08

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On Wed, 17 Dec 2008 22:25:13 +0000, Jonathan Schneider
<j...@jschneider.tenreversed> put finger to keyboard and composed:

I haven't checked all of the following, but they appear to be similar
parts with the same marking code:

http://www.microsemi.com/datasheets/MSC1378.PDF (SM05)
http://www.secosgmbh.com:8081/datasheet/products/TVS/SC-59/SMD03C~SMD36C.pdf
(SMD05C)
http://soft.laogu.com/datasheet/103/PJSMS05_PANJIT_87495.pdf (PJSMS05)
http://www.datasheet4u.com/html/S/M/3/SM36TC_SemtechCorporation.pdf.html
(SM05)
http://www.datasheetarchive.com/pdf-datasheets/Datasheets-40/DSA-791422.pdf
(WOST05C)

- Franc Zabkar
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N_Cook

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Dec 18, 2008, 5:27:02 AM12/18/08

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Michael A. Terrell <mike.t...@earthlink.net> wrote in message
news:qKKdndfuMLRMO9TU...@earthlink.com...

Are manufacturer's allowed to put whatever code they like on devices ?
So is it possible to have 2 functionally different devices (on same
package?) with the same code ?

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Michael A. Terrell

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Dec 18, 2008, 8:09:51 PM12/18/08

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N_Cook wrote:

>
> Michael A. Terrell wrote:
> >
> > They generally use code numbers, not part of the actual number. There
> > are a couple databses on line like this one to help identify SMD semis.
> >
> > http://www.marsport.org.uk/smd/mainframe.htm
> >

> Are manufacturer's allowed to put whatever code they like on devices ?
> So is it possible to have 2 functionally different devices (on same
> package?) with the same code ?

Did you look at the link? It happens, quite often. OEMs don't check
with each other to see if someone else is using the same code. They
don't care, because it is an internal product ID for their use, so
people loading pick & place machines can look at the marking and make
sure they have the right part. Its not THEIR problem if you buy parts
from someone else using the same code.

You have to have an idea what the part does, then look for parts
using that code that would do the job.