I have a black nexus 5, recently updated to 4.4.3. And I've got those random reboots. One of these the phone don't come out of it. Stays off. When I try to turn on It only shows the Google Logo, vibrates and then turns off, sometimes it stays bootlooping for a while.
I've tried to get to the recovery menu, and I couldn't. I've send it to the LG here in Brazil, and they can't fix it.
Anyone knows any alternatives?