Date   : Sun, 01 Oct 2006 21:07:05 +1300
From   : Michael Foot <mjfoot@...>
Subject: Re: One more BBC B to fix

Hi,

In message <$c58DJAT2qHFFwxe@...>
          Mike Tomlinson <mike@...> wrote:

> 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?

Yes I have since they are both socketed. The current VIDPROC is a VTI one
so I assume in the past the original VIDPROC was replaced with the current one.

Do you think the fault is caused by a video circuit problem? Do you think
it's more likely to be IC related, connection related or some other component?

Thanks,

Mike.

-- 
Michael Foot <mjfoot(at)paradise(dot)net(dot)nz> *
http://homepages.paradise.net.nz/mjfoot/
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