Various issues with Wii remotes

Hey everyone,
I just created an account in hopes of finding some help from someone experienced enough.
I have a bunch of Wii remotes with various issues. Some of them are corroded beyond repair, but others seem fine but only have minor issues.

The most annoying part are the Wii remotes that won’t sync to the console (Wii or Wii U). And yes, I’ve tried everything that’s part of the normal troubleshooting process. New batteries, restarting the console, plugging the console out and back in, trying other Wii remotes to make sure they work etc.

The other problem I’ve come across is that some buttons don’t work. most of them I was able to replace, like the minus, home and plus buttons. However now I have remotes where the “1” or “2” buttons don’t work. My idea was to run a wire to wherever the button leads, however when I try to follow the trace it goes to a via and then seemingly a dead end. I know the signal has to go somewhere but even when trying to find a component with my multimeter (on a working remote!) I get nothing.

I’ve even found this picture of a circuit diagram that shows where the signals are supposed to go, but it shows “U1”, which I can’t find anywhere on my remote. Maybe it’s a different model of sorts?
(I can’t embed pictures yet, if someone wants to see it, it’s the first google images result under ‘wii remote circuit diagram’)

Sorry for this long post but I hope someone has a solution for this.
Thanks in advance!