Date   : Thu, 19 May 2005 14:08:35 +0100
From   : Sprow <info@...>
Subject: Re: RAM chips for Model B

In article <1116474621.428c0cfdcc78d@...>,
   Michael Foot <mjfoot@...> wrote:

[snip]

> 1) Faulty RAM.
> 2) Faulty track(s) joining the RAM chips.
> 3) Faulty 74LS51
> 4) Faulty 74LS139

One extra to try, the 74LS273 that isolates the teletext chip from the rest
of the world. On issue 7's it should be socketted, so easy to try, but would
also suggest (since the others aren't socketted) that Acorn had a problem
with them...
Sprow.