Tuning pots on the neck board.. guide?

[JoeB]

Is there a good guide, written in plain english with lots of pictures and examples, on how to tune the pots on the neck board for optimal correct video output??

I'm especially interested in tuning by WG 7000 series 25" monitor.  I'm pretty good at tuning all the pots on the remote board and pots on the chasis.. but the picture can still be better.

Can I tune it while the monitor is running? is there a way to find the sweet spot? Any help would be highly appreciated.

[Ken Layton]

Generally it's best to have a test pattern of all 4 colors (R-G-B and white) in a 'staircase' pattern displayed on the screen at the same time while adjusting the trimpots on the neck board. Street Fighter 2's built-in monitor test pattern in the game's test mode is perfect for doing this.

Set all the DRIVE pots at their mechanical halfway point. These are VR202 (Red), VR204 (Green), and VR206 (Blue). Now adjust the CUTOFF controls VR201 (Red), VR203 (Green), and VR205 (Blue) until each of their staircase patterns extend equally across the screen about half thru their range. As you adjust you'll see the white change from yellowish to white . You may need to adjust black level (brightness) and contrast too.

If you look in the k7000 manual you'll see that the factory suggests using an oscilloscope for best colors. I do ok by just using the Street Fighter 2 board for adjustments.

[exibar]

Use the Nokia test pattern generator to help you set everything up.  You can download it at retrogaming.com I believe.

[JoeB]

Ken.. you're the man!  

I played around with the pots on the neck board.. and WOW.. does it ever look sweet now!  The blue isn't running, and I can tell the difference between blue and purple in puzzle bobble!!

Everything looks very very good!

Now.. I did notice one small problem (after playing with the Nokia calibration tool) the red gun is about 1/2mm to the left of the rest of the guns.

Is there any info on the web on how to set convergence properly on this WG 7191?  WG was "kind" enough to remove all their tech docs for this monitor from their web site.  

[Ken Layton]

The convergence is well documeted in the K7000 manual at www.mikesarcade.com (the 7191 is considered a k7000 series)

Wells hasn't had anything on their site pertaining to the old models in a long long time.

[JoeB]

WOW!

That's a serious procedure!  By the looks of things, I need to do dynamic realignment (if I'm not mistaken) since I notice the red beam only on the right most side of the screen.. it only is visible when the whole screen is white!

When playing, it all looks good.  I might just leave (I assume there's no harm done, right?)

Also.. where the heck can I find those wedges!?

[Ken Layton]

Bob Roberts sells the rubber wedges as does Wells-Gardner's parts dept.