Date   : Sat, 30 Sep 2006 18:46:59 +0100
From   : Mike Tomlinson <mike@...>
Subject: Re: One more BBC B to fix

In article <6ef7606e4e%mjfoot@...>, Michael Foot
<mjfoot@...> writes

>I've got an Issue 4 Model B here which won't start up. The best I can get it to 
>work is in 16k mode (jumper 26 south). In this setup, most of the time when 
>switched on a random configuration will occur. Usually the RGB output is 
>completely white and the Caps LED comes on then goes off. Usually, but not 
>always, I can press Ctrl-Break after this and different LEDs will light up and 
>sometimes the RGB output goes black. Also, on only a small number of occassions 
>the machine will boot to a prompt but then lock up a few seconds later.

Have you swapped out the VIDPROC and ic14 (74LS245)?  If the VIDPROC is
the Ferranti one, does it have the heatsink?

If ic14 is not socketed, try piggybacking it (put another one on top,
hold it down with a finger so the pins make contact with the pins on the
soldered one) and switch on.

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