Re: Apple ][+ keyboard problem, please help!

[Rubywand <rubywand@swbell.net>]

Wayne Stewart writes ...
> 
> Vince Briel wrote ...
> > I have an Apple ][+ that I have had for a while and was working fine
> > last month, now the 1,2,a,s return and space bar keys stopped working.
 ....
> 
> There's only two likely possibilities. One side of those particular switches
> are on the same circuit which end up at pin 36 of your AY3600. It might just
> be a bad connection so you might try removing and replacing your keyboard
> encoder board. Also while you have the encoder board off lift up and scrunch
> down the AY3600 chip. Might be marked KR3600 0r something.
> If it's not oxidized connections then possibly it might be a bad AY3600.
 ....

     Didn't know the AY3600 was ever used in a II+. That explains why the KB
diagram in the Apple II Reference Manual doesn't match the symptoms described
by Vince. There would be nearly no way for just 1, 2, A, S, SPC, and CR to
suddenly go bad with the MM5740 encoder.


Rubywand