Misc Why doesn't the sync button work on the Wii U gamepad?

[BRIFIN]

it all started when a friend of mine mixed up the positions when he was fixing the charger from the wii u gamepad + and - because of which it stopped working and he sold the wii u to me for a symbolic price. I’m not very knowledgeable about repairing equipment, so I ordered the board on AliExpress, the board works completely, but the sync button doesn’t work. At the same time, I checked the button and 2 cables to the motherboard, they are not broken (the problem is not with them). Could it be that the problem is in the board with the “turn on” “TV” buttons and indicators? If not, what could be the problem on the main board?

 

[Xyphoseos]

Nice turorial

 

[BRIFIN]

Thank you very much for your answer, but unfortunately I can’t follow the link, could you send me screenshots or text from this site that could help me?