[Jeffhs]

In the early '70s I had a Sears Silvertone 21" color roundie TV, with circuit boards in every stage except the horizontal output. The video output board cracked and broke one day when I tried to replace the 6AW8 video output tube.

I've been leery of PC boards ever since, and will not attempt to repair one again. I know Zenith all but swore by PC boards in their transistor radios, even the later Royal 500s (I believe the first ones were actually hand-wired on a metal chassis), and even their televisions of the '70s (think the modular Chromacolor II sets), but these were solid-state and did not require (actually were not designed for) service at the board level--the modular Chromacolor IIs and other Zenith TVs from the seventies until the end of the Zenith era were "repaired" eight times out of ten simply by replacing modules. I have two Zenith radios, a 13-transistor portable from 1980 and a clock radio of the same vintage, both with nearly the entire set on one board.

PC boards are great for applications where high heat is not a problem (read solid-state) and/or frequent repairs are not required, but not, IMHO, for devices that use tubes, especially tubes that run very hot such as horizontal or audio outputs. The extreme heat from these tubes weakens the PC board over time, eventually making the latter so brittle it will crack if you so much as sneeze on it.

Another major trouble spot in many TVs with PC boards was poor connections and/or breaks in the boards around heavy components such as flybacks, power and output transformers, etc. These sets probably would have lasted longer and been easier to repair had the larger components been mounted somewhere off the PC panel, say on a small aluminum chassis; however, this would add to the cost of building the sets, which in turn would be passed on to the consumer in the form of higher prices for the sets in the stores. The small 12" TVs with single PC boards were meant to be sold cheaply and were made to reflect their low price, not to be easily repairable when they needed service. Most of these sets were trashed at the first sign of trouble any more serious than a bad tube; even then some people (probably most) didn't bother getting it fixed if the set only cost them, say, $60 or less when it was new.

With the outrageous rates TV shops charge simply to look at a set, let alone repair it, I don't blame these folks one bit. The smaller tube-powered portables, IMHO, just aren't worth it. I would not have a recent-vintage (read five years old or less) solid state 5" TV/AM-FM radio repaired, either, as cheap as these are nowadays (if they can even be found anymore).

The only exception I might make to the above (having a recent vintage 5" TV repaired when it went bad, and was out of warranty) would be if I had a 5" Zenith battery/AC-DC TV with radio. These weren't cheap when new, although they show up at very reasonable prices once in a while on eBay. However, being Zeniths, these little sets were made solidly and to last a long time. It wouldn't surprise me if they were modular as well; if so, they would be easy to repair....that is, if one can find the modules (or parts, if these sets were built on single PC boards) these days.