just swapped tubes on a Neotec 27E .. now

Bullwinkle

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I just swapped tubes because the blue gun was not working in the old tube (used a bk 467 to verify). Put the new tube on, but now I seem to have a geometry issue. The colors now are spot on, but the sides of the picture bow in and i'm missing about 2" of screen from both the top and the bottom. V-size shrinks it to where it is...but when I go the other way it really stretches it out. I don't believe it did this with the old tube, is there something I can do to correct this?

Thanks,

Tom
 

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By swapping tubes, you left the yokes on each tube, correct? Your yokes must be slightly different, if you swap them as well it should fix it, but sometimes you can't do that very easily.
 
I like to take pictures of things before I remove them. Then if I forget something, I have a reference. Just try remember to position the yoke exactly as it was on the old tube.
As for a clean swap, I got lucky a couple of weeks ago and swapped yokes, loosened the screws and each slid off the neck quite easily.
 
I like to take pictures of things before I remove them. Then if I forget something, I have a reference. Just try remember to position the yoke exactly as it was on the old tube.
As for a clean swap, I got lucky a couple of weeks ago and swapped yokes, loosened the screws and each slid off the neck quite easily.

pictures is an excellent idea and I'll take a crapload, thanks. Here's hoping for the easy swap!
 
Well, pictures definitely helped. Got the new yoke on and the picture came up with beautifully correct colors... Just need yo adjust the width. But I played a few games and it was awesome. So I went to take a picture to post and (this is no joke) the second I went to snap the pic, the screen went dark!

Now I have no neck glow but when I apply power to it, I hear that warm crackle you hear when a monitor /tv turns on. It had just been recapped and got a new flyback and HOT prior to the tube swap. I pulled the HOT and it tests fine. Wow is this a frustrating monitor! I did read the 25E's flow chart and some steps from Ken Layton and checked R432 (22k) and R431 (10k). And changed out C424 from a 10uf 50v to a 10uf 200v even though it appeared to be fine. Any other suggestions?

Thanks
 
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