Question Computer shuts off after 45 minutes to an hour

[Dad2323]

So this problem started a few months ago, but I haven't really touched it since so for all intents, let's say it's a new problem.

I use my computer almost exclusively for gaming, which it crashed during, so I assumed it was a heat related issue, as it won't turn back on for nearly an hour after it kicks the bucket. So I applied some new thermal paste. No dice. I then downloaded CoreTemp, and booted up a game constantly checking, never peaked over 45 C and still shut off. So I'm almost certain it's not my CPU or GPU (i5 4690k and Nvidia 1050 respectively), neither are that old, but not brand new either.
Later I discovered my power strip was on the fritz and I've just replaced it today and I'm hoping that this is the answer, but not betting on it.
So before I crash again, I was hoping to get some insight into if you guys think it might be my PSU or my motherboard before I go out and spend $100 on a replacement part. Or if maybe I need a clean install (hopefully not).
I believe I have a 550w PSU and I'm using a Gigabyte mother board (got locked out of Steam so don't know another quick way to look it up). Haven't tried loading in Bios as I'm just now trying to solve this issue but if you guys think it's worth it I'll try to see if it crashes then.
Edit: I don't even have to be playing a game for the crashes to occur, even if I just boot it and log in it will eventually crash. However I do believe there is a correlation between more demanding games and an earlier crash time. As playing DOTA 2 caused me to crash after 40 minutes while playing Mount and Blade (which could run on a potato probably) I lasted for well over an hour.

 

[acecreator26]

So this problem started a few months ago, but I haven't really touched it since so for all intents, let's say it's a new problem.

I use my computer almost exclusively for gaming, which it crashed during, so I assumed it was a heat related issue, as it won't turn back on for nearly an hour after it kicks the bucket. So I applied some new thermal paste. No dice. I then downloaded CoreTemp, and booted up a game constantly checking, never peaked over 45 C and still shut off. So I'm almost certain it's not my CPU or GPU (i5 4690k and Nvidia 1050 respectively), neither are that old, but not brand new either.
Later I discovered my power strip was on the fritz and I've just replaced it today and I'm hoping that this is the answer, but not betting on it.
So before I crash again, I was hoping to get some insight into if you guys think it might be my PSU or my motherboard before I go out and spend $100 on a replacement part. Or if maybe I need a clean install (hopefully not).
I believe I have a 550w PSU and I'm using a Gigabyte mother board (got locked out of Steam so don't know another quick way to look it up). Haven't tried loading in Bios as I'm just now trying to solve this issue but if you guys think it's worth it I'll try to see if it crashes then.
Edit: I don't even have to be playing a game for the crashes to occur, even if I just boot it and log in it will eventually crash. However I do believe there is a correlation between more demanding games and an earlier crash time. As playing DOTA 2 caused me to crash after 40 minutes while playing Mount and Blade (which could run on a potato probably) I lasted for well over an hour.

Did purchasing a new power strip solve your issue?

 

[Dad2323]

I have yet to crash! So that's a tentative maybe (I have no intention of jinxing myself out of $100 for a new component at this point). Where I got locked out of Steam, I haven't been able to play a game to stress test it yet. And heavens knows when Valve will actually reply to my request, but I'll post an update if it crashes again or I'm able to stress test it, whichever comes first.