Computer crash when playing games

[OfficialDavve]

Hi I'm typing this for a friend, he was playing rainbow six siege with me and his computer crashed for some reason and it won't turn on again.
He said that this had happened before and he just waited until the computer started itself.
The monitor has power so can it be the power supply that is broken in some way?
He also told me that the computer wasn't overheated in any way.
Last time the computer crashed like this it took some hours before it restarted itself.
Thanks for help in advance.

 

[constantine_99]

might be software problem too, but since software problem usually gives warning, like BSoD, i would presume the PSU is the problem here.
consider on changing it