I purchased a new system a month or so ago. It has been running well for the most part. i7 processor, 8 gigs of ram, HD7850 etc.....
One problem. If I leave it on for a while when I come back my samsung monitor is flashing and when I move the mouse it usually comes back into windows 7 but it does not come back on. The monitor continues to flash. I have to manually restart by holding the power button which I hate to do as I am afraid over time that will damage the computer.
I turned off sleep mode but that had no effect.
I have taken it back to the store and they cannot reproduce the problem.
I am pretty good with computers but not extremeley teksavvy.
Use monitors own control system to disable sleep or set it to detect the main input rather than use automatic mode.
Hard-restarting the computer will not damage the computer "over time." If you do it during a software update you may mess something up, but otherwise you'll just lose your changes to any unsaved files you have open.
"...when I move the mouse it usually comes back into windows 7 but it does not come back on." - if the monitor does not come on how do your know it 'comes back into windows'?