Chosen Solution
So this problem kind of occurred out of the blue. My left joycon is not working. When I slide it into the switch It’s only recognized for a second and Then continually flickers between being connected and not being connected. It only stays connected for a second at a time. When I take the joycon off the switch it cannot connect at all. Like the switch does not even recognize it no matter what buttons I push. I tried switching out my joycons since I have a second pair and they worked for a while and then the same issue happened on the same side. The right side has been working perfectly fine. I have no clue whats broken or what parts I need to replace. If it helps at all I got my switch five months after launch.
Assuming it’s not the joy cons, as you said the issue persists with a different joy con controller, it sounds like it might be a problem with the rail conector on the side of the unit.
These aren’t overly difficult to replace and dont require soldering.
To looking for “Joy-Con R (Right) Connector Ribbon + Rail Nintendo Switch”
it’s not a very expensive part and would be my first port of call, after that there’s a potential that a damaged rail may have damaged the ribbon connections on both the joy cons you’ve inserted, so they may need their ribbon connections replacing also, but I’d go with the rail first and see how you get on.
