PC Black Screens Randomly Whilst Playing Games

My PC has recently started "black screening" when playing both Rainbow Six: Siege and Overwatch. The monitor will go to sleep as if it is receiving no input and I am unable to wake it back up. The only known fix is a full system reboot. Sound continues, with Spotify working in every situation and TeamSpeak continuing to work most of the time as well. My games immediately crash, as well as a few other programs which control my RGB lighting. I have tried updating all of my drivers, to no avail. This ONLY occurs while I am playing games and has happened about 10 times in the past week.

The only recent change I have made was adding in-case RGB-LEDs which are powered via a USB 2.0 motherboard header.

Any and all help is appreciated.

Specs: Intel i7-4820k @3.7GHz

EVGA GTX 1060SSC 6GB

ASUS P9X79 (ATX, LGA2011)

Corsair CX750M PSU (750 Watts)

4x Corsair Vengeance 8Gb 1333Mhz DDR3

2x Corsair Vengeance 8Gb 1600Mhz DDR3

Samsung 850Evo 500MB

WD Blue 1TB 7200RPM