I can recall the day my Mom's '80 Mercedes 300SD wouldn't shut off-it happened, of course, on a rainy day when she had taken my sisters and some of their friends to a shopping mall an hour away. Luckily she got someone on the phone who could tell her what to do.
I guess that Zenith has diodes, at least? How many color sets didn't have some sort of diode?
My best 'tubes to the rescue' story came a few years ago-towards the end of our town's annual carnival someone stole the solid state PA we used to call bingo. Out of storage came the 50 year old no-name tube amp-it worked fine, and folks commented that it sounded better than the new amp! Afterwards I decided to recap it and use it in the future instead of buying a replacement-after the recap the power transformer went up in smoke
Anyway, I have since dredged up a pair of tube amps: a Bogen that I guess dates to about 1948 for Bingo & a Muzak that isn't much newer which I have hooked up to make announcements over the carnival grounds. The speakers I rigged up were some I found in storage, big bullhorns that have to be from the fifties or earlier. Mostly 'Atlas Sound'. I used this setup for the carnival this year; the Bogen blew a fuse one night but other than that everything behaved and sounded great!