Date   : Wed, 27 Feb 2008 08:50:40 -0600
From   : jules.richardson99@... (Jules Richardson)
Subject: Dead BBC B ... FIXED

Bob Devries wrote:
> Well, dunno what was wrong, but I reseated some of the chips, and it now 
> works great. Must have been a bad connection somewhere.

Possibly just dirt/corrosion on the IC legs or associated sockets. My "top 
five" checks for any dead machine are typically:

1) Visual inspection for dirt / corrosion / conductive contaminants etc.
2) PSU (test in isolation with a dummy load)
3) Check all capacitors for shorts / high-ESR
4) Re-seat any socketed chips (& check for damaged pins)
5) Check for CPU reset, clock, and any bus activity

... the first three I'll do on any machine that hasn't been powered up in a 
long time; 'blindly' turning an old machine on can really do some damage!

I've not found many bad solder joints in old machines (displays are another 
matter!), but it does happen occasionally. The BBC seems pretty immune (the 
PCBs and solder work are good quality), but I've known the PCB tags where the 
PSU cables connect to break once in a while.

cheers

Jules