[Q] Shield Buttons work parcially topic

I need help. 2 days ago that I have a problem with the buttons of Shield

They work parcially

Nvidia Button: Rather than launching Shield Hub, it makes Shield sleep (but i can shut down and reboot)
Home button doesn't works (No multitask, no Google Now)
Back button: Sometimes works, sometimes doesn't
Pause button: Only for Game Mapper

Luckly, A,B,X,Y, joysticks, d-pad, bumpers and triggers, work perfectly

I tried to do a wipe but when I enter recovery mode, i get a message that says "Any command". Anyway, i did a hard reset by the System configurations (and not be solved)

Someone more it has happened this? How i can solve it?

Sorry for my bad English, i'm using my poor knowledge of English and a translator

Thanks!