PCjr Monitor Color Convergence Adjustments

[tempest]

I did something stupid.

Somehow the color convergence on my IBM PCjr monitor has become off. The bottom was perfect, but the top half of the screen was off. Figuring I had nothing to lose I started adjusting the rings on the yoke (thankfully there's some white glue that sort of tells you the general area they should go), but no matter what I do I can't seem to get it right. I come close, but it's never right. I have the rings back to where they were originally (as far as I can tell from the white glue marks) but it's worse than it was originally. Are there any tips for adjusting the rings? Maybe something that tell me which rings affect what. I think my main problem is that it's not just a matter of adjusting the distance between the 'tabs' on each set of rings, but the position of set of rings in relation to the other sets of rings seems to also make a difference (makes sense given I'm screwing with magnetic fields). So there are a ton of things that can be adjusted and at the moment I'm just sort of randomly moving things in hopes of getting it right.

I can post of pictures of what it looks like now if that helps.

 

[tempest]

The more I look into this the worse it seems to get. On the startup screen (the one with the IBM logo and the color bars) I can see that the blue bar on the far left appears to be a few pixels lower than the rest and the there are one or two others (magenta for example) that are one pixel or so higher than they should be. Maybe this indicates a bigger problem than the magnet rings?

 

[T-R-A]

Sure it doesn't (or didn't at first) just need(ed) degaussing?

 

[tempest]

I don't know, maybe? I tried using a magnet to sort of degauss it but it didn't seem to do anything (maybe I need a more powerful magnet?). Here's a picture of what it looks like using the PCjr diagnostics:

http://atariprotos.com/temp/pcjr_3.jpg
http://atariprotos.com/temp/pcjr_4.jpg

 

[tempest]

Well, today I learned about something called Dynamic Convergence. Basically I had to grab the yoke and move it up and down to get the colors to align. Lo and behold it's MUCH better. It's pretty much perfect now other than some minor red convergence issue in the upper right (VERY minor).