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Hole in a transistor

canactech

Jul 7, 2009
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Hi, I have a problem with a RS-232 communication card that goes on an Epson TM-T88IV thrmal printer. There is a SOT-23 transistor with a hole in it so I cannot find the identification number. The circuit is identified as UB-SO1 model M111A, RS232 I/F BOARD, Parts 2116250, set 2116251. The transistor is supposed to be Q1. I need the model number of that transistor to be able to replace it by the same type.

Thank you for your help.

Canactech
 

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
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It's more than probable that something else failed which caused Q1 to pop like that. Do you know if the printer was hit by a mains spike?

Posting clear photos of both sides of the board may help.

Chris
 

canactech

Jul 7, 2009
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Concerning the photos, I've treid to do some but the circuit is very small and the camera that I,ve treid are not able to make a clear photo or you will see nothing because the image will be too small.

Something that can maybe help you is that on the case of a transistor on another card there is two numbers: 14 print horizontally and 16 printed vertically. But it could be only production code so I don't know if it will be usefull.

Thanks.

Pierre
 

CDRIVE

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Sorry but that doesn't help.

Chris
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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There are a couple of things you can try.

Firstly, if you can find a working printer, read the markings from a good transistor.

Secondly, look at all the transistors on the board with the same package and see if there are only 1 or 2 types. If there are, then it *may* be one of these.

Thirdly, post good pictures and see if we can work something out.

when you say
The problem happens after a power cut
, do you mean "happened" or has this occurred multiple times?
 
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