Screen goes blank and buzzing

i have recently built a desktop the specs are as follows
asrock h77 pro4 m
intel i3 3220 @ 3.3ghz
16gb ram
msi afterburner graphics card the 7770
wireless adapter
windows 8
randomly when playing films my screen will go blank and buzz and lock out and i have to force a reset on my tower i have adjusted overclock function on the graphics card several times and have also adjusted power settings to max so desktop doesnt hibernate ive had my sony bravia tv tested and changed my hdmi to different brands and still the same my laptop has never had the same issue and will run films through my tv all day long with no issue