Question PC randomly rebooting


Sep 3, 2017
Apologies if this is the wrong place for this.

My computer has started to restart randomly without bluescreen or any info about what went wrong. Just playing games and then computer the screen just goes dark and computer reboots.
Temperatures are all ok, I even re-applied thermal paste and liquid metal to my delidded cpu. I turned off overclocking on my GPU, I didn't have overclock on my CPU GPU drivers are up to date.
A few months ago I upgraded RAM from 2x8gb to 4x8gb, but the problem only started recently. Memtest86 shows no errors after running it for a couple of hours. Same with stress testing GPU and CPU. No errors.
Windows event log only shows events 6008, 41 for unexpected shut down and recently event 46 for crash dump failed.

How do I start troubleshooting what the problem might be?

OS: Windows 10 18363
Motherboard: Asus STRIX Z270F GAMING
CPU: Intel Kaby Lake i7-7700K, LGA1151, 4.2GHz
CPU cooler: Corsair Hydro H45
GPU: MSI GeForce RTX 2070 Super VENTUS OC
RAM: 2x HyperX Fury DDR4 2666 MHz, CL15, 2x HyperX Fury, DDR4 2666MHz, CL16
PSU: Corsair 750W RM750x
Storage: Kingston 480GB SSDNow UV400 (OS installed here).
Intel 660p NVMe PCIe M.2 1TB SSD.
Western Digital 1TB 7200rpm hard drive.