Edge Convergence after Tube Swap - Need Help

tjc02002

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Electrohome G07. Cap Kit installed. B+ 120V. All adjustments work well. The chassis has the curl mod done.

I did a tube swap and the monitor looks really good, except the convergence on the very top and bottom edges all the way across. Its actually worse in the middle of the edges and better in the corners. I swapped the yoke from the arcade monitor, and have tried for hours to get the convergence right. I can get the center perfect. I can get the lines that pass through the center perfect all the way out to the edges. The only problem is the horizontal lines away from the center wont allow the magenta to converge with the green. It seems like the green is too far out. There is no adjustment for this and I am wondering if the tube is not quite compatible with the yoke. The old tube had 19v90 stamped into the glass, but the new one has 20v90 stamped into it. It came from a 19" TV and the tube is exactly the same size as the old tube and the bolt spacing and fit was perfect.

I used the purity/convergence rings original to the TV tube that is swapped in. They were perfectly marked for position, and replaced exactly where they were from. I have adjusted them for hours and the middle converges perfectly.

I installed the yoke at a certain distance to get the purity right. Then I can rock it up/down or left/right to get the outer edges to converge. I can get the red/blue all over the screen to converge perfectly, but at the upper and lower edges, the green and magenta wont line up. Its reallly not that bad, but its noticeable to me...

I have tried convergence strips, and they work great in the corners, but dont quite get the magenta to move into the green line to fix my edge problem. I noticed another person on here had this problem, but it didnt seem resolved. If anyone has experience with this please let me know any possible solutions. Thank you very much.

-Tom
 
That is what i thought, but does it make sense that the physical size of the tube was exactly the same as the 19" and it came from a 19" tv but it is a 20" tube? I measured them multiple times and had them right next to each other, they were within 1/16 of an inch in all dimensions. Believe it or not, the 20V90 tube was maybe even a little smaller then the 19V90 that came out...

Could this be the reason the green doesnt converge at center of the top and bottom edges? I have another donor TV, so I am considering swapping it out again.
 
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Ok. The Shan Man just confirmed that the tube could be the problem. Not all tubes will converge perfectly with all yokes. Plus the 20V90 thing makes sense. I guess I am in for another tube swap. Luckily I kinda enjoy working on this thing...
 
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Yeah, its really not that bad. its only off like two pixels at the edges. I made a picture of what the problem is. I tried taking a real picture but it was too large to upload, and it really didnt come out that noticeable.

Im wondering if different convergence rings, or moving the whole set of rings up/down will change anything. If I move the yoke in/out it helps this problem but it screws up the purity.
 

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I'm dealing with the exact same problem...just hours ago. I got a 1998 19" Samsung I picked up off the road. Impedance readings were slightly close to a g07 but I pulled everything off the g07 and put it on the new tube. Moving the yoke in and out I could finally get my colors correct (I originally had it too close), but using the g07 convergence rings I could only get the center converged well and not the outer corners. I only have 4 strips which allowed me to make 1 corner tolerable, but I've got to try to find more to do the other corners. One thing I didn't try was moving all of the convergence rings in and out...does that do anything?
 
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