Goodmorning, last March I purchased a Nexus 5, but since two weeks, the screen has begun to shake, wobbling and then freezing like in the picture below...The screen shows this image even if I try to reboot the sistem or if I try to boot in fastboot mode. The problem goes away after something like 10/15 mins of shutdown, but after a day or two, it comes back. I tried to unroot the phone and installing again stock Android (I used Cyanogenmod) and nothing seems to be solved. What could it be? A firmware issue? An hardware issue (more likely)? Should I contact Google assistance for a new device?