This happened on my Toshiba Satellite C55 running Ubuntu 16.04 LTS after the last update. I ran "xrandr --auto" once after finally getting into the GUI by booting into maintenance mode and resuming normal boot. It seems to have fixed the problem for the time being. I can close the lid for sleep mode and upon opening the lid, the screen comes back with the login prompt, even after a power down. I am mystified.
This happened on my Toshiba Satellite C55 running Ubuntu 16.04 LTS after the last update. I ran "xrandr --auto" once after finally getting into the GUI by booting into maintenance mode and resuming normal boot. It seems to have fixed the problem for the time being. I can close the lid for sleep mode and upon opening the lid, the screen comes back with the login prompt, even after a power down. I am mystified.