You can harvest the transformers for a couple junk microwaves to make an arc welder.

If you aren’t experienced then pretty much all power supplies, battery backups, and motors should be left to someone else.

I saw someone lose a finger (later reattached) to a washing machine with a jammed tub. It was plugged in and on when they reached underneath it and yanked the belt, their sleeve ducked their hand into the drive wheel.

That said, if it fits your personality it can be both fun and satisfying to learn how to fix stuff. I try to teach anyone who’s interested and asks. Except LG washing machines, those things can fuck right off.