Date   : Sat, 13 Aug 2011 21:24:15 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: Advice on restoring a dead Beeb?

>> This is a pretty common failure mode. Unfortunately, almost anything
>> could be responsible. Can you let us know what advice you have followed
>> so that we know what you've tried or eliminated already?
>
> Is there a step-by-step guide for this available?

I have a new updated concise service manual available on fleabay:

http://cgi.ebay.co.uk/250872488872

>
> There are, IIRC, a number of small gotchas - for example you can't try
> starting the Beeb without its keyboard......

Yes you can, remove the System VIA and the motherboard should boot to the 
BASIC prompt if all is well - the only other thing you'll lose beside 
keyboard control if you do that is the sound, as the System VIA controls the 
sound and speech chips as well. Once you get the board to a state of booting 
to that point, then you can refit the System VIA and work any faults from 
there.

> Ditto. I've yet to experience a ROM (or, for that matter, EPROM) failure
> that wasn't my own fault - like plugging it in upside down, or
> quick-programming that didn't quite "take".

Those Hitachi Mask ROMs that are the most common are usually very reliable, 
I've not had one fail on me on a BBC Motherboard, although I have seen Mask 
ROMs fail in other applications.

Mark.