PC Turns off during gaming?

[bheemdushman]

greetings community,
Here's my parts list:

https://uk.************.com/list/9P2QXH

Describe your problem. List any error messages and symptoms. Be descriptive.

When I'm playing certain games (GuildWars2 on high settings was a problem yesterday) my PC will suddenly and with no warning turn off. I've run some OCCT stress tests and can only replicate the problem if I run the power supply test, the CPU and GPU tests run fine.

List anything you've done in attempt to diagnose or fix the problem.

I Googled around for what could be the cause. It seemed like insufficient power could be the issue? I've checked and I've got a 750w PSU, and PCPP says that my machine needs 361W, that's a healthy buffer right?

Provide any additional details you wish below.

What else could be the problem? What else could I try?

Also, if some you experienced PC builders could take a look at my current build, does anything seem woefully outdated? I'm happy with how my machine runs currently but it's in my head that I might need to upgrade something soon. What's likely to be the component that needs switching out first?
Thanks!
Tutuapp 9apps install ShowBox

 

[Spankme]

have u got anything overclocked?

 

[Lemin]

Your psu can still have failures. Can you borrow another to test.

 

[strumpusplunket]

Does this happen instantly you load up the games or after a period of time? (How long?) You mention high settings - do the games work on lower settings?

Is this a new problem? Was you system working okay up until recently? Have you changed anything? Any new components?

Have you monitored your temperatures when playing games and stress-testing?