Today I got my nexus 5, but unfortunately I have a lot of problems. After entering my Google account information and walk away for 5 minutes, my phone was locked. When I came back, I wanted to unlock my phone. My phone failed, and the screen remained black. I tried to play, what with the buttons, but the screen remained black. I received some weird stripes, and the phone was very hot. After a while the phone restarts, and came back in android. Then I got an update to 4.4.2, after restarting everything seemed to work well. After an hour I got the same problems again, phone failed, and the screen remained black and locked. I get a message about QHUSB_BULK driver is not installed, and MTP failed.
Phone is factory and nothing is installed, it was the first setup.
So now I'm still with a black screen and locked phone