G07 Convergence, what is good enough?

plgDavid

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Hi

After a capkit and B+ pot repair, I'm pretty happy with my G07/Chassis, except from the color alignment. Before I start messing with the rings (I'm scared of making it worse), let me show you the pictures (from pengo self test) see attached.

The blue is particularly off. But is it a scenario that is tolerable in the sense that there is more chance that i might screw off the convergence completely?

Also is there any video or in depbt text that shows the effect of moving those rings around?
The best I've found was :
"The furthest set move the red/blue in relation to eachother.
The second aligns this combination to the green.
The third is for color purity.

Rocking the yoke will either turn horizontal lines from a smiley or sad line into a straight one,
or expand one of the colors outwards or inwards along the vertical axis.
You should have a grid if you are gonna rock the yoke.
In fact you should get a grid up for any of the adjustments to get them half precise.
(...)

Green should never move.. you are aligning everything onto the green.
You should use a red/blue (magenta) grid for the first rings,
then a white or yellow grid for the second set adjustments. "


Thanks a lot for any inputs!
 

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After a capkit and B+ pot repair, I'm pretty happy with my G07/Chassis, except from the color alignment. Before I start messing with the rings (I'm scared of making it worse), let me show you the pictures (from pengo self test) see attached.

The blue is particularly off. But is it a scenario that is tolerable in the sense that there is more chance that i might screw off the convergence completely?
I don't think your monitor is half-bad. If you're motivated then give it a shot. Although I was afraid for a long time, it's easier than people say and these old monitors are usually in pretty bad shape to begin with.

You should test with a different screen. You want something that can generate a full-screen grid or dots with variable colors. The colorbars you show are mainly for brightness and color adjustment. If Pengo doesn't do it then wire-up some JAMMA board that has better monitor test patterns.

Degauss the monitor fully. Mark a line before you release the screws; if all else fails you can use the line and put the rings in their original position. Adjust according to the recommendations online. You can probably do better than the photos.
 
You should test with a different screen. You want something that can generate a full-screen grid or dots with variable colors. The colorbars you show are mainly for brightness and color adjustment. If Pengo doesn't do it then wire-up some JAMMA board that has better monitor test patterns.

Degauss the monitor fully. Mark a line before you release the screws; if all else fails you can use the line and put the rings in their original position. Adjust according to the recommendations online. You can probably do better than the photos.

Thanks,
I do have a few other boards (including full white grid tests), but I liked the fact that the pengo one showed straight colors as well.

Two questions from your answer:
"Mark a line before you release the screws" ... the convergence rings only budge if you release that 'key thing'? wont that unlock the full Yoke?

"Adjust according to the recommendations online", do you have a specific link? I didn't see a go to site for this. Only the very technical version in the G07 service manual.
[EDIT], I just read it again and yes the clamp must be loosened, and probably the "nail polish" must be removed .. gulb.
 
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I'm a novice and i found the adjustment to be friendly enough once i found the right write-ups that explained it clearly.

draw a marker line across rings so you know where it was when you started and easy to get back to.

from my monitor manual it had a picture of the starting point of the convergence rings.
from rear view, the starting point for adjustment being
2 together at 10 oclock
2 together at 2 oclock
2 together at 9 oclock
2 together at 3 oclock

then in a document called
http://personalpages.tds.net/~rcarlsen/cbm/converge.txt
i learned that you need to work in "ring pairs."
--when tabs together the magnetic fields cancel each other out
--separating the tabs moves the beams in a horizontal direction which affects the vertical lines
--rotating the tabs together moves the beams in a vertical direction affecting the horizontal lines.
 
"Mark a line before you release the screws" ... the convergence rings only budge if you release that 'key thing'? wont that unlock the full Yoke?
You'll see there are two pieces. The yoke has one lock, the rings have a separate lock. If you mark a line on the rings then you can always give-up and get them back to the starting configuration.

"Adjust according to the recommendations online", do you have a specific link? I didn't see a go to site for this. Only the very technical version in the G07 service manual.
The G07 manual is kind of terse. I'm sure everybody can provide good links, but here's one that might explain the big picture: http://wiki.arcadecontrols.com/wiki/Monitor_convergence_tutorial If I remember correctly your goal is:

1. Purity: each beam hits a single color evenly with no splotches of other colors. you'd use a solid red, solid green, and solid blue screen for this.
2. Convergence: each beam illuminates the same pixel. you'd use a crosshatch grid (or field of dots) for this and check that the beams line-up both in the center of the CRT and at the edges. they recommend certain color combinations so you compare red-blue, blue-green, red-green, etc.
3. Repeat #1 and #2 since these adjustments are all inter-related
4. Color balance: each beam illuminates to the correct brightness. you'd use color bars for this.
 
Thanks for all your help!

Also I know the G07 has a degaussing coil, but is it pertinent to buy a separate one to be sure the "native" one does its job correctly? The colors look the same on all sides of the screen however, so I dont know if it needs it.
 
Yes. The built-in coil triggers momentarily to correct for small problems. If you use a handheld coil then you can do a better job removing any magnetic field (metal frame, etc) that might affect your adjustments.
 
Yes. The built-in coil triggers momentarily to correct for small problems. If you use a handheld coil then you can do a better job removing any magnetic field (metal frame, etc) that might affect your adjustments.

Ok! Will start with this and attack the rings after. Will post results when i get the device.
Thanks
 
Here is another picture (1942 test mode hatch)

Seems only the blue is off and its worse in the bottom right corner.
 

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Since it's good in the center, don't mess with the magnetic rings.

To shift the colors around on the edges, you can try tilting the yoke slightly. That's called dynamic convergence and that's what the rubber wedges are for.

If it's pretty good around the edges except for one area, then I think it's time for the little convergence tabs on the strips of cardboard.

Kerry
 
hmmm, wasn't me. but i never knew about those things. i need some. my monitor has fresh caps and looks pretty good in the center but i can't get the outside converged. maybe that would do the trick.
 
Take a look at this video I made...

Is there a trick to that? I can never seem to do it properly. I can usually get everything but one or two corners converged, but when I go to the strips it never works that cleanly.
 
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