Another update on the Zenith 20Y1C48

[Carmine]

I just finished playing with the vert size and lin.

Vert size had litte to no effect, while the vert lin. expanded the picture a little. It does lock in for vert hold, but the adjustment is super critical.

Any thoughts? I would have expected a bad pot to make the screen occasionally "jump" to full size, but no luck. I did notice a SLIGHTLY smaller picture, with flicker at the bottom BEFORE any of the fuse blowing drama. I HOPE the cleaning solved any of this!

Also, I noticed a slight blue gas in the Vertical output tube when I tuned it on at night in the dark. I swapped it with another, and saw the gas again, in the same area! I also swapped this tube (6HE5) with a known-good tube earlier. All three tubes produced the same picture. Could something else cause the blue-gas problem???

Stumped