Date   : Mon, 04 Oct 2004 11:11:29 +0200 (CEST)
From   : "Carsten Brasholt" <carsten@...>
Subject: Re: Electron Sync problem

Thank you!

The composite video output is fine, so I'll just have to examine the
circuit board.

I used the same RGB cable as on my beeb, so this should be working as well.

Cheers,
Carsten

Jules Richardson
>
>> Whenever I connect the machine to my monitor, which works fine on my
>> Beeb,
>> The display rolls - There's nothing I can do on the monitor that will
>> make
>> it stop.
>
> Same cable or different? Sounds like total loss of sync, which could be
> cable (not if you've ruled it out on your beeb obviously), connector
> (not making contact, or broken joint on the PCB), or further back in the
> video chain. I'd rule out the former two first!
>
> Do you have a monitor with a phono input? If so, hook the Electron up
> with that from the video out and see if it works. If it does, then it
> would suggest a problem with IC14 (74LS86) or PCB track / solder joint /
> RGB cable.
>
> The only thing upstream of IC14 on the sync line is IC19 (74LS08) which
> might have failed and would knock out sync to all video outputs. Further
> back from that it's the main custom chip, in which case it's Game
> Over...
>
> Check LK3 has a jumper on it too; of it was left without one it could
> mess things up.
>
> cheers,
>
> Jules
>
>