Question PC crashing when booting / randomly when booted

[LorenzoMKW]

Hello,

This issue started occuring yesterday. I moved my PC to my brothers house last week and everything worked fine. I moved the PC back to my own house yesterday, connected everything, turned it on and it seemed to work fine.. Until it suddenly rebooted out of nowhere. Now everytime I turn my PC on it seems to reboot. There is no specific pattern. Sometimes it happens instantly and sometimes it happens after ~30 minutes.
I also reinstalled Windows which didn't help and I double checked all the connections on the motherboard, it all seems fine. Also reset my BIOS, removed the CMOS battery and I'm not overclocking anything.

I disconnected my GPU and connected my monitor to the onboard graphics and everything seems to be working fine now.

What could possibly be the problem?

Specs:
CPU: I7 8700k
MOBO: Gigabyte Z370 AORUS Ultra Gaming 2.0
Cooler: Kraken X62
GPU: MSI GeForce RTX 2080 GAMING X TRIO 8G
PSU: Cooler Master MWE Gold 750 Full Modular
RAM: GeIL Super Luce RGB GLS416GB3000C16ADC
SSD: Samsung 970 EVO 500 GB M.2

Video:

View: https://youtu.be/8SjTU8VMx50

 

[LorenzoMKW]

Update. It just rebooted while I was connected to the onboard graphics. So definitely not a GPU issue.. possibly the PSU?