Screen blank when playing dota 2

[Scrouga]

Guys help me please ! Im really confused right now .My PC can run all my other new modern games like shadow of mordor ,the witcher 3 etc normally but when im playing dota 2 sometimes my screen goes blank(black like when you disconnected it) and then restarting and screen wont appear again .Whats wrong with my PC?
My spec i3 4130 msi 750 oc version psu corsair vs450

 

[enm22]

Did you overclock either your CPU or graphics card?

 

[Scrouga]

No im not oc neither cpu nor gpu