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Re: gEDA-user: ngspice shot noise



On Tuesday 04 October 2005 12:50 am, Gene Heskett wrote:

> >> Virtually on the same day they sent us tens of thousands
> >> 2N2907 transistors, labeled as such.  Days later when none of
> >> the thousands of boards out of production worked correctly we
> >> discovered that in those 2N2907 cases where really 2N2222
> >> dies.

> >For those who don't recognize the numbers .....  2N2097 and
> >2N2222 are not interchangeable.  2N2907 is PNP.  2N2222 is NPN.
> >Oops.
>
> Tell that to the nincompoops on the production lines.  I've had to
> replace one with the other several times in brand new stuff.

How would the production people know?  The part called for in all of their 
documentation called for 2N2907's (PNP).  The part was marked just like they 
had always been in the past, 2N2907.  What was inside the 2N2907 package was 
the 2N2222 (NPN).  They don't have X-Ray vision to see inside the package, 
don't think it would help if they did.  Testing every part before it goes on 
a board is not a practical solution in a production environment either.