[compucat]

I recently replaced an electrolytic cap that went bad and got the old Zenith 25MC33 working again. Just the other day the vertical hold went way off and when I adjusted it back in the height had pulled in from the top and bottom about a quarter of the screen. I have noticed a blue glow in the vertical output tube. Can a gassy tube cause this? I turned the set off and on again and the picture returned to normal for a while. Also, it now occasionally comes on like the brightness control is way up, not all the way or with retrace lines. If I turn it off for a minute and then on again it is normal. It still has a lot of original Zenith tubes still in it.