Anything connected to your garage door.

That spring will fucking kill you.

Batteries

Old arcade machines. Giant capacitors + little knowledge on the subject = a very bad time.

As with anything it can be done safely if you know how. People still play those and they obviously need repairs/maintenance sometimes.

Holy shit, how has no one mentioned rechargable batteries?

Lithium Ion batteries, commonly used in phones and the like, rapidly catches fire and emits acidic smoke that will melt your lungs when the battery is punctured.

I too was going to say microwave before reading the post body. Honestly though anything with a large capacitor, I can’t give you examples unfortunately because I study physics not electrical engineering but some of those fat fucking capacitors will fry you and they hold their charge.

I was actually going to say microwaves, but specifically the thing where people use the parts to make those things where you can burn fractals into wood. They look super cool but apparently if you brush up against the wrong component your heart just stops.

I had a problem with the control panel in my Panasonic microwave and was able to fix it pretty easily. Everything I needed to get to was inside the right front of the microwave; the control pad membrane and the sticker that goes on the front of it.

This is why we have specialized people who you call to handle these things.

DO NOT backfeed your house’s electricity with a generator when your electricity gets shut down. You might electrocute someone working on those lines.

Microwave

Old CRT monitors. Particularly if they’ve been recently unplugged. There’s a cable in there my old teacher used to call “the superman cable”.

Ok firstly.

Never, work on anything that is still connected to a power supply.

This includes any stored energy. Isolate it first. Gravitational, electrical, pneumatic, hydraulic and chemical (if possible).

Don’t fuck with stored energy.

Secondly.

Learn how to test if things are live, or have any stored energy.

Thirdly.

Once you KNOW you are safe. Go hard, learn all you can.

CRT TVs.

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.

Air conditioner. I melted a screwdriver.