Re: Help with Thunderclock parts ID

[Osgeld <osgeld@cheesefactory.us>]

On Sep 9, 12:44 pm, "Apple2Steward" <n...@none.net> wrote:
> To my horror, I found that my Thunderclock had developed
> corrosion on the legs of several semiconductors, one of which had
> corroded through.
>
> I'm having a trouble identifying a few components for replacement
> and wonder if anyone who is well-versed in such things could
> help.
>
> A D1 there is a diode that has lost its painted-on markings.  It
> is next to R10, a 10% tol. resistor which has (reading from the
> other end) gray - red - black bands (82 ohms?).
>
> The worst transistor at Q3 is marked:
>
> F2N
> 3904
> EBC
>
> The other at Q4 is marked:
>
> ~202/
> 2N
> 3904
>
> (The "~" is actually the two National Semiconductor squiggles one
> above the other).
>
> Am I correct that the two transistors are the same:  2N3904, just
> from different manufacturers (Fairchild and National?)?
>
> What would be a likely replacement for the diode?  Would it be
> necessary to ID it from another Thunderclock or could I meter it?
>
> Any suggestions would be appreciated!!

what color is the diode? its probally just a standard signal diode

gray red black would be 82 ohms

3904 transistors are common place NPN transistors, I think you can
even get them at radio shack, and yea they are the same