I found a TV-Set in a dumpster, and checked if it's still working.
Indeed it is somewhat functional, but the picture is distorted:
(screenshot of the TV)
Depending how bright the picture is, it get's more or less vertically "compressed", where the upper half is more compressed than the lower part. The brighter the picture, the more compressed it becomes.
There is also a combing effect, and the picture seems horizontally slightly shrunk.
When the picture is very bright, as in almost white, the screen flashes, and sound disappears.
Also, the brighter the picture, the more 50Hz noise I can hear from the speakers.
I suspect either the V-control IC to be broken (TDA3653B), or one of the capacitors connected to it.
Or, some of the AC/DC capacitors might be dried out or otherwise broken.