Just received my new Nexus 4 and was messing about with the brightness settings and suddenly the screen went off. Knew the phone was still on as the screen still clicked and it received messages. The only way I could get it back on was doing a factory reset. Having done this, it seems that if I slide the brightness all the way to the left on it's lowest setting, the backlight actually turns off. I've found reports of Nexus 7s doing this suggesting that it's a software issue but seems very odd. Any ideas guys? Does your Nexus 4 do this. If you try it take care not to take your finger off the screen so you can slide it to the right and bring the backlight on again.