I'm on Ubuntu 14.04.2 on a HP Z230 workstation with dual monitors. Very often in the morning, the screens are just blank and don't seem to wake up from suspend / power save mode. To fix it, I need to go to
tty1 and reboot my PC.
I checked the "Power" settings and it's configured to "Don't Suspend" so it shouldn't be entering into any power save mode. This only seems to happen only overnight - my monitors always come back fine after a 1 hr lunch.