I had a 1961 Philco Briefcase 19 portable in the early '70s; it worked great, as soon as I got it home (it was a trash-day find in my old neighborhood). Didn't have to do a thing to it but plug it in. Used it as my daily watcher for quite a while, especially after my 1964 Silvertone roundie color set bit the dust in 1973 or so (cracked video output PCB).
That Silvertone was in bad shape anyhow; just before the video PCB cracked I had hum bars in the picture, on-again-off-again color sync that could almost always be brought back to normal by turning the tint control from red to green and back again, the convergence was terrible (I didn't have a dot-bar generator at the time; I tried to set the convergence by using the vertical line produced when the service switch was in the service position, but no luck--I think I just made things worse), you name it. The sound was still good, although when the PC board broke I lost that too.
When I eventually moved in 1975 I left that set behind for my then-stepmother (whith whom my dad and I had been living since 1972, before she divorced him three years later) to deal with.
I kept the Philco a year or two after returning to my home town (it still worked for a while), but the set eventually died and was put out for the trash. What goes around comes around.
As for Zenith, I have a Sentry 2 color set made in 1995 that still works great, and still has its original CRT. I only use it these days to cross-check when I'm having problems with my cable service, though it was my daily watcher for four years at my former residence. Never had even so much as one repair done on the set. Considering how troublesome Zenith CRTs were in the 1990s, I think I was very lucky to have gotten a set with a good tube. This one has 11 years on it and is still going strong; since the Zenith TV doesn't get much use in my apartment (I bought a new RCA CTC185 when I moved here), it should last at least a few more years--I sincerely hope so. At least the lightning-bolt Zenith logo on my set actually means the TV was manufactured by Zenith, even though the company's color sets were being built in Mexico for Zenith Electronics Corporation in Missouri at the time.
My point is that 1990s-vintage Zenith TVs weren't all bad. There were a few that went years without developing CRT problems or severe chassis troubles as many of the newer Zeniths (after Gold Star bought the company and moved it offshore--grrrrrrrr) had, such as the video circuits going up in smoke when the CRT eventually shorted.
I all but swore that I would never buy another GS-manufactured "Zenith" branded TV immediately after Zenith sold out to them; heaven knows I'd never buy an LG flat-panel for the same reasons. I really shouldn't knock LG, though, as I have a cell phone made by them that still works great, even after falling to the ground front first when I tripped on a sidewalk in my old neighborhood and fell in 2005 (the phone was in a case on my belt, which is probably what saved it from being smashed to bits when it hit the ground; I was not nearly so lucky, but that's another story).