I tried turning my vertical position on a refurbished chassis. Image shows what I have right now. Turning V size does not help screen size...what simple thing am I missing?
that would be allot more work but you could do it yes.
but i do not think it will solve your problem.
what does the B+ measure on your chassis.
if it is low it will not fill the screen.
it should be 130vdc.
just a suggestion turn all the pots on the chassis so you can verify that they all work. and that the screen does not get bigger or smaller when you turn the V-Size pot. it is strange that you are only getting the smaller image.
another thing to check MAKE sure your ANODE cap is in the tube ALL the way. i have seen that affect the screen size as well if not clipped under the lip with both clips in the anode cup.
you'll also need to re-adjust all the color pots on the neckboard. you have a strong blue tint in the picture. I'm thinking it's not a tube issue cause I don't see diagonal lines in the screen.
would vertical IC failure cause this, or is that an absolute either it works or you're going to just have a horizontal line? lol