Re: Apple ][ motherboard and trace restoration

["Luke Forat" <iceman@nospamdigidude.homeip.net>]

    Phil,

    your track drawing reconstruction looks ok to me. In any case, based on
the schematic, pin 11 of the 74ls257 is connected to pin 2 (Dsr) of the
74ls194 shift register located in A10 (which also comes from pin 11 of A2 a
quad 2 input nand gate which output is set to high to pullup). So you can
check it out with a tester in Ohms (1K scale will do fine) simply by
connecting one lead to the edge of the ripped off track making certain you
can get to some copper under the green enamel and the other lead on pin 2 of
A10 or pin 11 of A2. This will verify if that's your track.

    Luke

-- 
"Namachari" <lord_philip@mac.com> wrote in message
1137585425.856451.135360@g14g2000cwa.googlegroups.com">news:1137585425.856451.135360@g14g2000cwa.googlegroups.com...
> Hey guys,

> My best guess is that there was once a trace line that goes from pin 11
> that then dissapears under the keyboard socket and from there I have
> know idea (possibly to the IC at A2???). I have tried to look at the
> schematics in my copy of the RED book, but I'm no electronics wizz and
> I can't see any indication of pin 11 being attached to anything.
> For those wanting to help, I have made a little web page showing the
> trace line in question:
>
> http://homepage.mac.com/lord_philip/PhotoAlbum21.html
>
> The red lines are the trace lines that I am fairly sure are correct.
> The purple line is the one I am unsure of. Is this correct?
>
> Thanks for everyones time.
>
> Phil
>