MB: Asus P8z77-v Pro.
Graphic card: Sapphire HD 7950 Vapor-X.
I customized my power plan in the OS so that the monitor sleeps after 5 minutes of inactivity. At first the monitor turns off , but after a few minutes, it turns on: the LCD's colours turn to black, instead of the panel/back-light turning off. The mouse cursor also stays idle in the center of the screen.
I tried with a different monitor, but nothing has changed.
I've just updated all the drivers: monitor, keybord, mouse, Graphic card...Same problem.