Computer randomly shutting down and restarting; no blue screen; shut down and power button unresponsive.

[LightInfernal]

Hello, This may be long winded, but i'm going to try and give as much information as possible.

Parts List:
CPU: Intel 5790k not overclocked ( liquid cooled with an all in one radiator that i don't remember the name of)
GPU: nVidia GTX 980 ti
MB: MSI X99A Sli Plus
PSU: EVGA Supernova 1050G
RAM: G Skill Ripjaws 4
HDD/SSD: a 1TB Western Digital, and 2 SanDisk SATA SSDs

My computer for the past week has shut off with no warning, nor blue screen, generally after playing graphically intense video games such as Divinity 2, or Black Desert. Normally, it just restarts immediately, but just now it shut off and stayed off, the front power switch is unresponsive as well.

Before it shutting off for good, i tested replacing and removing the power strip it was attached to, as well as plugging it straight into the wall, and it still powers off after 30 or so minutes of graphically intense gameplay. I used some software to measure temperatures the moment before it shuts off, and the temps are normal (30 - 50 C for processor, 60 - 73 C for Graphics card).

The past shutdown put it in the state it is in now:

Current State: When i have it plugged in, the lights on the I/O shield blink on and the Ethernet port light stays on. The power button is also lit on the Motherboard, but it , and the reset button is unresponsive. The switch on the back of the case controls the lights going on or off, the PSU Switch seems to do nothing.

I have a suspicion its some sort of PSU problem, although it did start happening after i installed a different monitor (a phillips 32'' monitor(i can get detailed name if necessary)).

Am i correct in this assumption, is there any way i can test this without having to swap parts or use a rig?. or do i have to get it professionally diagnosed.

Any help is greatly appreciated. I'll be here to give more info if necessary.

 

[animemangamer]

OP, I'm no expert but surely I've experience a similar problem in one of my past builds so I'll try to help.

1. Perform this common test to check if your PSU is functioning as it should be. I know it's extra work but I highly recommend you take the PSU out of your case like in the video to rule out any ground issue If it works fine then let's do step 2:

[video="https://www.youtube.com/watch?v=5FWXgQSokF4"][/video]

2. Instead of checking loose connections I suggest you COMPLETELY DISASSEMBLE your rig and re-assemble it with fresh CPU Thermal Paste. Double check every connection specially the AIO CPU cooler. Make sure the Memory Ram and GPU are properly seated. Make sure there are NO PSU cables touching the case/chassis or motherboard. When you turn the system on try to feel if the AIO Liquid CPU Cooler you have is running try to feel it by touching the pump area.

3. If you've done everything you can think of and the issue continues then I assume it's time to replace your Mobo or upgrade to a new one + CPU.

I sometimes suggest people to reinstall their O/S and completely wipe their drives but I don't think this applies to you. This problem is definitely hardware related.

Goodluck OP @.@!