Got My Zenith Going Again
 

After about six months or more of downtime I got my Zenith 25MC33 roundie running again. The vertical had shrunk to about half size and tube changes did not fix it. It turned out to be a bad electrolytic cap in the vertical output circuit. I replaced the cobbled together convergence neck components with some of the recent spare parts I got from TV Tommy. I replaced the tubes in the color circuits, most of which were original. I had been having a little trouble with the color. Specifically the backgrounds would be a little too green until the set had been on for about five minutes then you could see it snap into normal. I went through a complete setup of the entire set including checking the horizontal output cathode current, high voltage, convergence and greyscale. I even got most of that annoying buzz out of the sound. The set is working great again and is ready to resume regular service. I have noticed that this set is quite a bit more maintenance intensive than all of my black and white vintage sets. Once restored, the b&w sets seem to go for five or more years without needing anything but this color set, my only tube color TV, seems to need more attention. I know the tube count is a lot higher but keeping this thing running definitely takes more than any b&w set. I want to bring home an early RCA console b&w set that was offered to me but my wife says that if I bring that home, I have to sell the roundie. I have to say, I am thinking about it. I just seem to get better reliability out of the black and whites and they are easier to repair.

Ohh hell no!! Keep the color roundie, much more impressive and watchable. Once you get the problems worked out it will be ok, yes they do require a bit more attn but the reward is worth it.
You can cut down on the problems by reducing the line voltage to around 110. This seriously reduces heat and strain on everything in the set.
The 26mc series are good chassis once you get all the bugs worked out.

I've found the same, color sets just need more frequent repairs, that's why I cut my color collection down to just my 3 favorites: remote ctc-10 console, Zenith 25MC33 (in the chinese console cabinet - sc400 remote), and the Zenith Avanti (with the 25EC58 chassis - and the sc600 remote) - And opposite of what you would expect I've actually had the least problems with the ctc-10. Of all the different sets I've owned, the Zenith b/w sets from the late-50s through the early-70s are what I've found to be the most reliable televisions overall.

I just got a 1952 RCA black and white console I am starting to dig into. It will be interesting to see how reliable it turns out to be.

I will probably be selling the Zenith roundie very soon as I promised my wife if I bought the RCA I would sell the Zenith. Not much room to accumulate sets around here.