How can I fix my B button?
We can press it down, but it does nothing. It used to act like it was stuck down and constantly register being pushed even if it wasn't. Now it just doesnt work at all.
This is a touch-screen controller associated with the Wii U video game console. It was released on November 18th, 2012, and available in black or white. Model number: WUP-010(USA)
Sounds to me like you said it - somethings stuck down there preventing a connection.
Have a look at the Wii U tear down on this site.
If you take the thing apart, I think you'll likely see what's causing it.
It could be something stuck on there or simply the button being slightly dislodged.