Computer shuts down when GPU on load

Krisdm

Reputable
Jan 4, 2016
3
0
4,510
I built my computer about a year and a half ago. Recently it has started shutting down randomly when gaming. I brought it home by car (which may have damaged it?) and now I can only game for around 20 - 60 minutes before the computer just shuts off. Sometimes it shuts off immediately as the game goes into full screen. For general use (Browsing internet, watching films, editing documents whatever) it is fine with no shut downs at all only when running graphics intensive programs.
I'm sure this isnt a overheating problem as my cpu caps at 46 under stress testing and gpu (with the games I play) at 65 degrees celsius. So I presume its a PSU problem? Looking for second opinions.
Also I got an RGB mouse and keyboard for christmas (which obviously draws more power) but I think my PSU should be able to handle these?

Specs (havent changed since building)
CPU: AMD FX-4300
GPU: Sapphire R9 270X
PSU: CX500M
Mobo: GIGABYTE 970A-DS3P
RAM: 8GB Corsair Vengeance DDR3