Date   : Tue, 14 Apr 2009 00:35:42 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: Easter Disaster

Hi.

Suspect the RAM first, the custom ICs are usually bomb proof. The only thing 
I've had go with regularity on Master boards are the RAM or the VIAs. If 
you've got a spare 41464, try piggy it onto each RAM chip in turn (only 2 
are used for the main RAM, the other 2 are SWR, but I can't remember which 
ones with the diagram not infront of me) then turn the power on, see if it 
makes a difference. If not, you may well end up as others have said, break 
out the soldering iron and the scope.

Mark.

----- Original Message ----- 
From: "Ian Wolstenholme" <bbcmailinglist@...>


I was measuring somewhere on the motherboard.  I know I did the Teletext
chip at one point because a screenful of random Teletext characters 
appeared.
Apart from that I don't remember anything unusual happening.  I've measured
the power connector voltages since the disaster and they are giving the 
correct
readings.  I've also measured most of the chips and they all seemed to be 
giving
5V or thereabouts, with the exception of the 26LS30 which was giving me 
about
9V.

There aren't any socketed chips so all I have been able to remove are the 
MOS
ROM and the keyboard, which I have tested in another machine and they are
working.

I left it on for a few minutes with the speaker unplugged and some of the 
chips
were getting warm like the vidproc and Teletext chip, but some others, which
I can't just recall offhand, were stone cold.  Which is good - warm or cold?

Best wishes,



Ian