In retrospect, it seems almost nuts that appliances from the past came with not only a block diagram, but a schematic. Especially now that everything is not only too complex to be documented "for your own good", and even potential repair techs, and now with DMCA protected software locks.

I still sometimes use the old Scott amplifier my parents got 50 years ago, with manual - and it has everything you need for a repair (besides a list of modern day replacement for some of these, of course). Same with the ol' Amiga 500 in a box over at their house. A lot of tinkering you could scheme on your own without going online (my quartz oscillator overclocking replacement never materialized, but hey).