How to preserve SNES hardware?
 

What are some tips to preserve and store my SNES Mini? I want him to be always functional

Standard electronics advice applies: Store it away from light, moisture, and other harmful elements (example: cigarette smoke). Use silica gel if needed, to reduce/remove moisture. Keep it in a temperature-regulated environment (interior closet), not in a garage of attic.

The issue with Nintendo hardware is two-fold: the plastics, the electronics. Plastic can discolor and become brittle. Electronics can short out due to thermal changes on the electronics.

I keep my old consoles (all the way back to the 70s family Pong unit!) in a dedicated wood cabinet in my living room. It's a really nice piece of furniture, and serves this function well.

I keep my SNES in a box on the shelf, the room where I keep the snes light enters during the day and the evening and the night is dark, the room is open and ventilated, humidity is 39 ~ 64% without rain, the room temperature is 30 ~ 36 degrees

I'm storing my Snes, power supply, control, AV cable correctly?