Left Joycon won't get recognised. Where to begin?

This a V2 switch. Tried every easy troubleshooting.

  1. Tried known good working joycon
  2. Replaced console and joycon side flex cable

Still nothing. Not sure how to check the condition of the capacitors or resistors. How do I go about tackling this? I’m ready to just use this as sacrificial board. I’ve done a fair bit of microsoldering, but just straightforward replacement, not something like this.

Thank you