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I lost a couple hours to an oddity, thought I'd pass on a heads up.  


Centari
(@centari)
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I have a batch of 2N2222 transistors that were packaged backward. (TO 92)  I was setting up a simple switch circuit which was not working correctly.  I spent much time double and triple checking my math, as I'm not great at math, but it all checked out.  This lead to bumbling and fumbling as well as a bit of fussing.  Nothing was making sense.  I finally pulled the transistor and put it in my tester, only to find out the package was backward.  The emitter and collector were reversed.  I put it back in the circuit, in a manner which should have been backward, and everything worked like it was supposed to.  China bargains are nice, up until they're not so nice.  😆 They still work like they should when backward. Packages marked.  Thought I'd pass it on to possibly save someone else some time....


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hstaam
(@hstaam)
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Thanks for sharing.

This never happened to me, though I had my fair share of fake transistors made in China.

hj

hj


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codecage
(@codecage)
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2centari

Thanks for the post!  I have a bad of 200 2N2222s that I haven't gotten into yet, but will soon for a project to build several boards and to be provided in a kit of parts for those wanting to assemble their own boards, so this is good to know.  I'll definitely test each one before including one in those kits!

SteveG


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Centari
(@centari)
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I tested half of the 100 I have, all were the same, which makes sense.  They are produced in batches, then sold in bunches from the batches. If you check a dozen to 20, and they all test the same, its safe to assume they are all the same. (good or bad)


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Sean451
(@sean451)
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What kind of device would you use to test a transistor?

--->Sean

(◕(' 人 ') ◕)


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Centari
(@centari)
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Topic starter  

sorry for the crap pictures.....

2021 02 13 134610

Cheap tester from E-Bay, does transistors, capacitors, inductors, and such.

2021 02 13 134639

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