Okay it makes sense now. The password saved on the console has been changed so the one registered no longer works, so the message displayed is asking him to enter the password again. If the gamepad was working, he would press OK and then it would open the keyboard, which is when an option to switch to the TV would be displayed on the TV. Obviously he can't get to the keyboard so I'll have to further look into this later, unless anyone else wants to take over from here. But the message is most probably saying the password for the NNID is incorrect, so if he somehow remembers the password he registered in the Wii U before he can change it back to that. I'l continue looking into it and get back to you later unless someone else here can help out. See you later then.