Need to Replace Convergence Pot

[TinCanAlley]

Originally Posted by Electronic M

I'd only replace the pots that are actually causing troubles, and honestly first I would try to clean those pots before considering replacement.... Don't want to open a can of worms.

They have been cleaned twice, but I get what you're saying. As it is now, I can't get the same results twice when adjusting. The first time I tried, I had a few bad converged areas and lived with it. Years later I did the same procedure and it was almost perfect. I then tried to touch up those areas, but couldn't and then couldn't get back to where it was before and now have even more areas that are off. I only made small changes based on the area and the pot that controlled it and still they didn't allow adjustment back to where it was.

The only thing I can think of is pots that are not up to the task anymore.

The oddest thing I ran into was during the static convergence. I moved the blue away so as to align the red and green. I got it dead on, but when I moved the blue in, the red and green would separate as soon as the blue got near the center of them. I could see the red go up and the green go down. I had to compromise on the blue a bit to where the red and green came back to their original positions. The dot is pretty much white in the center with a bit of color around the edges as I'm sure it is supposed to be.

[Electronic M]

Originally Posted by TinCanAlley

They have been cleaned twice, but I get what you're saying. As it is now, I can't get the same results twice when adjusting. The first time I tried, I had a few bad converged areas and lived with it. Years later I did the same procedure and it was almost perfect. I then tried to touch up those areas, but couldn't and then couldn't get back to where it was before and now have even more areas that are off. I only made small changes based on the area and the pot that controlled it and still they didn't allow adjustment back to where it was.

The only thing I can think of is pots that are not up to the task anymore.

The oddest thing I ran into was during the static convergence. I moved the blue away so as to align the red and green. I got it dead on, but when I moved the blue in, the red and green would separate as soon as the blue got near the center of them. I could see the red go up and the green go down. I had to compromise on the blue a bit to where the red and green came back to their original positions. The dot is pretty much white in the center with a bit of color around the edges as I'm sure it is supposed to be.

The convergence controls always have some interaction with each other. When going for red green convergence instead of moving blue off to la-la land, it's better to keep it close to the other two and bias the blue gun of the CRT to emissions cutoff so the blue phosphor doesn't light.

[TinCanAlley]

I think I will connect the gun killers of my pattern generator on the blue next time. That way I don't have to redo grayscale. The SM has the grayscale being done before convergence, but I'm not sure if that's truly necessary.