Re: WG6100 Problems (Please Help).

        That's what I'm doing. On my last try, I put heatshrink tubing
over the whole shebang (except for the two ends, of course) to make sure I
wasn't getting intermittant contact of the "center node" of the
back-to-back zeners.

        Still no dice.

Joe

On Tue, 19 Oct 1999, Rodger Boots wrote:

> It all depends what you mean by "back-to-back zeners". You
> should have one lead of each (either both cathodes or both anodes)
> connected together (NOT to the board) and the remaining leads
> connected from the input to ground.
>
> If you have both leads of both parts connected to the board there
> isn't going to be enough signal left to do very much.
>
>
> jwelser@ccwf.cc.utexas.edu wrote:
>
> > On Sun, 17 Oct 1999, John Robertson wrote:
> >
> > > Have you installed the over-deflection safety circuit? This is the zener
> > > diodes on the inputs to the monitor and are designed to limit the beam
> > > deflection to the maximum the transistors can handle. This info is about
> > > 1/8th of the way down, titled:
> > >
> > > Atari Color X-Y Display Deflection PCB
> > >
> > > This might save the monitor from further blow-ups caused by the logic board.
> > >
> > > John :-#)#
> >
> > I asked this question of the list a month or so ago, and didn't
> > get an answer, but John's message has prompted me to ask again....
> >
> > Has anybody gotten this to work, in practice? In theory, I know
> > that the back-to-back Zeners on the inputs should work, but in practice (I
> > have tried installing this on 3 or 4 different monitors -- Wells Gardner
> > and Amplifone) all this "upgrade" gives me is a solid spot-killer LED on
> > an otherwise working deflection board. If I remove the back-to-back
> > Zeners everything works fine again. Putting the Zeners on either channel
> > causes the problem.
> >
> > Am I missing something? Beofre someone suggests it, yes, I did
> > put the zeners together correctly...
> >
> > Joe
>

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Joseph J. Welser jwelser@ccwf.cc.utexas.edu
Design Engineer -- Crystal Semiconductor Corporation
Ph.D. Student in E.E. -- University of Texas at Austin
Work: jwelser_at_crystal.cirrus.com http://www.crystal.com
P.O. Box 17847; Austin, TX 78760
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Received on Tue Oct 19 07:53:32 1999