@RB: I think it was a matter of radiation level and phosphor element design. Electron guns put out a lot of radiation (x-ray machines were similarly bad), and the elements were not efficient. This changed into the late 80s and especially early 90s with better designs. I wonder whether the static images did put a strain on the circuitry of 70s TVs.
@Moogly: I've seen burn-in on LCDs. One had the quadranted windows logo, because the screensaver displayed it in the same places. The best screensaver is blank - except for those who might forget and then do something dumb.
> TV's were just crap back then. We used to have to get up an smash the top of the TV > to get the picture to quit rolling. > > Fond memories of that time period, but I sure don't miss vacuum tube TVs!
I miss the strong primary color images. Anyways, a decent brand gave at least ten years of good everyday use.