Another day, another joycon (actually, these are pretty satisfying because people tend to want these to work).
I was expecting another mashed in shoulder button, but instead when I opened this joycon, I found the shoulder button entirely missing. Goodness knows where it went (it wasn't inside the shell).
Replacing the button was straightforward, but annoyingly the placement was marginally off (by about 1.5mm) - which meant I needed to sand down the plastic of the trigger to allow for enough travel.
