Re: One other G08 Monitor question

If you are talking convergence, adjusting the yoke can help.

If what you have is a problem called "keystoning", though,
the problem is likely to be a shorted winding in the yoke.
This would look like the top width being smaller than the
bottom (or a similar effect from any edge to the opposite
edge). Since it's this particular monitor it could also be
caused by the deflection IC, it looks like they are doing
pincushion correction with that IC.

Since a DC offset somewhere could be compensated for
with the centering pots (but couldn't be compensated for
as far as pincushion correction goes), I'd be checking for
any DC problems. Are the +9.1 and -9.1 volt supplies
within their 5% tolerance (no more than .455 volts off)?
If you look at the X and Y drives from the game board
do they appear to have zero offset? (That's a little tricky
to test---feed both into a scope in XY mode and adjust
scope gains/centering for a good picture. Then set the
scope inputs to ground and make sure the dot is centered.
Turn the scope inputs back on and look for the picture to
be offset in any direction. If it is, the board can be the
problem. If it looks OK the monitor is the problem).

Matt Rossiter - Verio Southern California wrote:

> Well - I've actually got this thing completely fixed and looking pretty
> good. I'm just doing some fine adjustments to it. My question is this....
>
> On my Space Fury - I put the game into service mode where it will draw you
> a rectangle with three colored stripes in the center to adjust centering,
> convergence purity, etc. Well, my rectangle looks more like a trapezoid.
> My suspicion is - someone at the factory got lazy when adjusting the
> deflection yoke and didn't put the wedges in with the exact same preciseness
> that I would have if I was doing it. So I guess I might have to pull the
> wedges off and do the adjusting myself. I've done this with several other
> monitors and it's a big pain.
>
> Anyway - the question is - could there be anything else that is causing
> the picture to pull to the right? It's not so noticeable during game play
> except that some of the convergence goes out in the corners (Which bugs me
> of course).
>
> Thanks
>
> Matt
Received on Thu Dec 17 01:32:49 1998