Question Black screens?

[DeathFlows]

This issue has happened at least 4 times now in the past week. I'm gaming on guild wars 2 while having youtube open on my 2nd monitor and during some random times both of my monitors just turn black and show no signal. I turn them off and on but nothing happens. I have audio still going on like if im still playing the game or if i got a youtube video running the audio plays but no picture. can someone tell me why this keeps happening?

 

[PC Tailor]

Please post entire system spec including PSU make and model.