After just 2 years of use all the Joycons have knackered. Its not just the sticks (I can replace those myself) the shoulder buttons don't work on 2 of them and neither do the lights. I have never encountered such shoddy controllers. All my PS3 controllers have seen better days but ...
Cleaning the contacts on dirty cartridges with isopropyl alcohol and some Q-tips is easy, but if you do that and you find that you’re still having trouble getting games to work, you may need to clean the contacts in the Game Boy’s cartridge slot. ...