Re: Apple III ram problems

["Stefan Miganowicz" <nrsdpms1@tiac.net>]

Machine Fixed!  It turned out to be an IC chip on the motherboard and the
lamp was burnt too.  Thanks for the help!!


Stefan
Rubywand <rubywand@swbell.net> wrote in message
37A90671.EF666C65@swbell.net">news:37A90671.EF666C65@swbell.net...
> Stefan Miganowicz writes ...
> >
> > I was working fooling around with my Apple III.  It was working a couple
of
> > years ago, but the keyboard doesn't work.  I just got another Apple III
for
> > parts, and I took out the keyboard and put onto the one that worked
before.
> > Now it says Diagnostic RAM when I start it.  I swapped out the RAM card
that
> > was connected on the motherboard, and put another one.  It still said
the
> > same thing, so I think a chip is gone on the motherboard.  Before I swap
> > every chip out to find the bad one(I have another motherboard with
corrosion
> > on it),
>
>      The Apple III-- at least the early releases-- was famous for having
chips
> pop out of their sockets. Whether or not your Apple III is one of these,
after
> so many years, it's a good idea to assume that some socketed IC's have
pins
> which are not making good contact.
>
>      Try scootching up and re-socketing each IC-- this should wipe off
corrosion
> and reestablish good pin contacts. If you find any gross corrosion-- like
the
> pins are black-- you should probably wipe the pins with fine sandpaper to
remove
> the black coating. (Do this in a low static environment.)  An alternative
> recommended by George Rentovich is soaking the IC's in a shot glass of
Tarnex.
>
>      Before removing any IC, it is helpful to mark the IC and its socket
with a
> dab of whiteout. This helps to prevent re-inserting the IC backwards.
>
>
>
> > could someone tell me what chips are the RAM chips on the
> > motherboard.  And a wierd pattern comes up and the manual says it is
> > supposed to tell the bad chip, but all it looks like is a test screen.
>  ....
>
>      Don't know anything about the Apple III motherboard layout. Any RAM
is
> likely to be a set of 8-32 same-numbered IC's in rows of 8. When viewing a
> diagnostic screen which is supposed to indicate "bad RAM", look for any
markers
> which indicate position on an 8x4 (8x1, etc.) grid.
>
>      One place you may be able to get helpful Apple III info is Washington
Apple
> Pi. Their URL is http://www.wap.org/info/ .  Good luck with getting your
'III
> going!
>
>
>
> Rubywand