Date   : Sun, 11 Apr 2010 19:32:35 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: Dead beeb - easy tests

> My London based beeb has decided to pack in this weekend. Symptoms are
> continuous beep at switch on, Caps lock on from start shift lock comes on
> after 1/2 second.
>
> Tried swapping 6522s no difference.
>
> No cursor on screen but I think the processor is doing something as the
> shift lock ceases to come on if 6502 or LS245 are removed.
>
> Any ideas of simple tests without any test gear...if not it will have to
> come back to civilisation where I can show it to a scope...

Swapover the link at S25, that changes it to 16K, and swaps the RAM bank 
used for zero page, sometimes that shows up a RAM fault. Removing the LS245 
will make it a-la-dodo, as it needs that to interface to the RAM, so try 
swapping that out if the 1MHz bus one is socketed.

Mark.