suddent black screens

[Xusu]

so i've been experiencing random black screens.

these come at random, sometimes when playing games, sometimes when rendering, sometimes at the desktop with 0 load.

When the black screen comes the pc stays one but the monitor says "no signal" 

to fix this i need to plug my pc out of the wall and press the on off button thingy on the psu,

sometimes it still wont open. it takes a few tries. 

 

i've taken off my gpus overclock but is there anything else i should do? 

i'm pretty new with pcs.

[Xusu]

it just did it again