CurtPalme.com Home Theater Forum

RickNa · Joined: 04 Mar 2010 Posts: 45 Location: Rome, NY

New tubes, replaced yokes, adjusted the DY yoke to get them properly leveled, that's all ok.

However, I cannot get the green tube extremes (corners, sides) focused. I am able to focus the center but at the extremes
the lines on the patterns are fat. I've done the zones with the ME pattern and there doesn't seem to be anything I can do to alter the bluntness of these areas. I adjusted the schlemping (sp?) screws and they seem to have no effect either.

The red tube looks good. I am having problems with the blue tube as well but that one hasn't been replaced yet.

Are there any other yoke adjustments that might affect this problem beyond the frontmost DY yoke?

Any insight would be great, I've had this setup in focus in the past so I don't know why I can't get the green tube to focus correctly. I've gone through the steps in the manual but to no avail.

Put up a picture and the center area looks pretty good but the outsides are definitely blurry.

Thanks,
Rick

**Curt Palme** · Posted: Sun Jan 15, 2012 7:34 pm Post subject:

This can be mechanical or electronic. Put on sunglasses and see if the tube face is in focus. I'll bet it is. If so, then you need to turn the large screws above the lenses on the front of each tube mounting assembly. Gray in color I believe, and they are multiturn screws. That shifts the shimming between the tube and the lens assembly.

If the tube face is blurry, make sure you have the focus yoke connectors plugged in. You probably need to go into the focus menu and tweak the astig settings (2 pole and 4 pole settings in the focus menu) for each area.

RickNa · Joined: 04 Mar 2010 Posts: 45 Location: Rome, NY

You were right (of course). I was able to get good focus on the green but it was through alot of experimentation. I just couldn't figure out which way to adjust the screws that adjust the zenith and then I'd occasionally over adjust some parameters and I'd get the EBH error and it would shut down. Luckily I knew how to recover from that.

I had it all set and then went to watch something and I wasn't happy with it - went back in and the focus was all screwed up again and I had to start over. Now I've saved the focus and registration data by holding the memory key down for 5 seconds.

Is that all I have to do to ensure the adjustments aren't lost? Is there anything else I should do?

I don't want to go through this process again until I get the new blue tube. The blue tube didn't focus very well and when I look at the CRT image, it too is a little fuzzy, I presume that's simply because the tube is worn.

Even with that, I couldn't get the red as good as I'd like. But for now it will have to do. My eyes are buggin' out after all day with this.

I wish there was someone here that does this, it's a pain to do. In Seattle, I had a guy but in upstate NY, I don't think there would be anyone close enough. If, per chance anyone knows someone in this area that can do convergence on a G90, let me know.

Rick

**Curt Palme** · Posted: Mon Jan 16, 2012 10:21 pm Post subject:

No, the focusing really doesn't change on EM focusing sets much as the tubes age. I looked at an 18,000 hour G90 last year (!), and although the tubes were rated a -1 out of 1 to 10, they still focused OK.

A big key with these sets is the astigmatism. If the defocused dots aren't round, then you'll never get good focus. Use the 'all' adjustment in the middle setting to defocus the dots in the focus adjust mode. Make sure as you go from defocused to focused and back to defocused that the dots stay round. If they go oval or to a straight line, your other 4 settings are off.

Also, do the optical focusing first, and set the contrast to 95 or so. That will stress the tubes out a bit focusing-wise, and once you dial the tubes in for best focusing at max contrast, they'll look fantastic at normal contrast.

RickNa · Joined: 04 Mar 2010 Posts: 45 Location: Rome, NY

Looks like the focusing is finally pretty much dialed in, not as good as I'd like but I can only do this stuff for so long (especially when you get to the blue gun, drives your eyes batty!).

Still have some questions if anyone knows, please help.

The red tube need to be set at max size to adjust the vertical to match the other tubes, any ideas why that may be happening? Becaues of that I have trouble getting the rest of the registration data right for the red tube since there's no leeway on the size adjustment for the red tube.

Question about video memory. I set the video memory to 5 for the component input (my DirecTV box) and thought I could use the same memory for my Bluray but when I assign it, the image is stretched out in the vertical. It is defaulting to vid memory #14, not sure why. The input setting doesn't allow you to set a memory above 10 so I don't even know how that got set that way in the first place.

Lastly, I seem to lose registration data when I flip between input 1 and input 2. I have done the "hard save", holding the memory key down for 5 seconds and saving both the registration data and the focus data but when I went back to the DirectTV source (input 1), there was some new skew in the color registration that I had to go in and fix it again.

For those that may be reading, I had to go between adjusting the tilt of the crt face plates (grey screws on the face of each tube housing) and focusing interatively before I got something decent. The dot focus approach would not work for the extemem outside edge that well on all colors so I did the best I could and then went back to the "ME" pattern and ran trhough the focus again.

Do any of the other yoke collars besides the MG have an issue of alignment if they are not positioned correctly?

Thank in advance.

Rick