CNET’s Sean Hollister sent his desynchronizing Joy-Con controller to Nintendo for a repair, and within a week he received his controller back and found that it was functioning properly.
Earlier teardown videos placed the blame for the disconnection issues on the left Joy-Con’s internal antenna, which is built into the motherboard instead of being a separate piece. In an apparent attempt to limit any interference that could be responsible for the issues, Nintendo placed a small square of what appears to be conductive foam right on top of the antenna.
It’s a simple solution that seems to fix any issues you might be having with the controllers, and one that shouldn’t require any technical know-how. A large chunk of conductive foam — easily enough to fix your controllers, your friends’ controllers, and anyone’s controllers in a 10-mile radius — will set you back about $25.
For an even more permanent solution, you can also try soldering on an extra wire that runs along the length of the left Joy-Con. This extends the antenna while also limiting any interference that it might be receiving, but it’s not something we would recommend doing without prior soldering experience — a disconnecting controller could quickly turn into one that doesn’t work at all.
