This is why manuals are so damn important! Communicating to people 20+, maybe 50+ years in the future, what you've done, how the thing works, so it can be fixed and put back into service. All of today's undocumented soon-to-be-black-bricks--cough, I mean, electronic devices--are maddening. If you are lucky, there is a manual somewhere online, and even then, probably not the level that details hardware for fixing and replacing. Heck, you're lucky to find anything that even documents all the software functions available![1] (Recent Xfinity TV thingy, I'm looking at you). The attention to detail in older manuals was incredible. Most things these days are throwaway pieces of junk, not expensive, serviceable items that have durable documentation.
[1] I mean, why would you document the software of a device that is going to upgrade its software transparently as the manufacturer races to finish the features it should have shipped with, or alter the UI to inject ads into it later when their revenue model doesn't work out? Besides, you expect consumers to just give up on it and buy the next thing in 3-5 years.