sony trinitron KV-20S30

Kenny301 · Post by **Kenny301** » Wed Sep 07, 2016 3:20 am

Hi guys, new to the shmups forum here. Just got this this past weekend for free on craigslist as I've been wanting a trinitron for awhile now. 20 inches of trinitron goodness. Great picture, but I think the convergence is a little off and the picture is a little red. I turned down the "screen" pot on the flyback near the edge where the picture cuts off. I tried putting it right at the edge and it goes to black, but when I go to put the back cover on and turn it on, I don't get a picture unless I turn that pot up a hair or two and the picture comes up, so I just put it near the edge where it won't do that and I think it's the best it's ever gonna get. About the convergence, it's most noticeable on the upper left. Any suggestions on what I should do to get the best picture quality from this thing? https://dl.dropboxusercontent.com/u/763 ... 036493.jpg https://dl.dropboxusercontent.com/u/763 ... 925426.jpg%20https://dl.dropboxusercontent.com/u/763 ... 858274.jpg https://dl.dropboxusercontent.com/u/763 ... 103553.jpg%20https://dl.dropboxusercontent.com/u/763 ... 222458.jpg https://dl.dropboxusercontent.com/u/763 ... 317547.jpg

Kenny301 · Post by **Kenny301** » Sun Sep 11, 2016 8:57 pm

Anyone? Since it has a bit of a convergence issue. I decided to attempt to adjust the rings on the yoke to see if it would improve and now I can't seem to get it perfect. I notice it doesn't have those magnetic strips in place as I've heard that those would fix the corners of the convergence or something. I get a corner good and a corner goes bad. Is there a good setting for the rings that they should be on? Hows the picture? Of course this was before I took the back off. What should I do to get the best convergence and picture possible? I turned that screen pot down a hair or two and I get the black level I want, but I'll have to wait 30 secs to a minute for the picture to come up which I' fine with. The convergence is so frustrating and really bothering me right now and I want the convergence to be perfect.

LDigital · Post by **LDigital** » Sun Sep 11, 2016 11:21 pm

I think you should have left all physical settings alone until you tried using the engineers menus to correct your issues. Jumping straight in with pot and yoke adjustments is crazy

Kenny301 · Post by **Kenny301** » Mon Sep 12, 2016 12:16 am

I know. I thought that would fix my issue. Is it worth getting those convergence magnetic strips to get the corners right?

phase3 · Post by **phase3** » Mon Sep 12, 2016 4:14 am

Kenny301 wrote:I know. I thought that would fix my issue. Is it worth getting those convergence magnetic strips to get the corners right?

I think LDigital is referring to the service menus in the TV itself.
Take a look at this thread from a while back. Many of the kind fellows here helped me solve a similar but different issue.
http://shmups.system11.org/viewtopic.php?f=6&t=55818

Taiyaki · Post by **Taiyaki** » Mon Sep 12, 2016 5:10 am

Normally you don't resort to touching the yoke unless the picture seems dramatically off. I've never moved the rings on the yoke but just nudging it or pulling/repositioning the entire yoke makes dramatic changes to geometry and convergence.

The screen knob is the G2, you probably shouldn't have touched it.

Can you get it back to where it was approximately?

If it's convergence you were after there should be at least one convergence knob (could be two) next to the phase and focus knobs.

If it's just a slightly deconverged area in a corner or two then it's best to get magnetic strips and work with those (they're also called permalloy strips). If it's a wee bit of convergence issue, of the type you can only see while 1~2 feet from your set (with a mid size 20~24 inch set) then it's probably normal, you can only get it so close to perfection.

Based on those screenshots it does look like it should be possible to improve it somewhat, but overall just there it certainly doesn't look that bad to me.

As for the magnetic strips yes they're absolutely worth it. They do take A LOT of practice to get right, as you move it around you'll see both geometry and convergence change. It's a bit of an art to get to the perfect spots to improve both or maintain the one right and fix the one off. Sometimes you can use a few in a single spot. Of course goes without saying, be extremely careful where you put your hands, dealing with very high voltages there.

Kenny301 · Post by **Kenny301** » Sun Sep 18, 2016 4:40 am

That screen pot was turned way up resulting in the photo showing the purplish screen. Once I got the black levels I wanted, I left it there. I got the yoke rings close to where they were originally (took a pic). I think I'm satisfied other than the corners. I'm definitely going to get those strips when I can.

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