Display doesn't wake up from automatic turn sleep

Hello, I would like to ask a question about my desktop here. After upgrading to Windows 8.1, I noticed that there has been a problem with my display. It doesn't happen everytime, but randomly, when the computer is idle for 10 minutes and the screen is automatically turned off, it won't turn back on anymore. Normally, I will just move the mouse and the display will turn back on again. However, when the problem happens, no matter what I do, moving the mouse, typing in the keyboard, it won't turn back on. I even tried to press the shutdown button, thinking that the computer is just sleeping and it will wake up again, however it doesn't do anything. The only thing that works is the restart button... I've tried every way to try and stop the problem: uninstalling the graphic drivers and reinstall the latest beta drivers, uninstall the drivers again and install the WHQL drivers, installing monitor drivers, checking out the power options and making sure that the computer isn't set to sleep after a timeout period... Nothing works, the problem will still randomly happen again after the desktop turns off the display monitor. My graphic card is Sapphire Radeon R9 270.. does anyone have any solution to this problem of mine? Help is greatly appreciated, I'm very tired of this happening suddenly, I do not want to lose my data from restarting the computer...