Brother's PC (new build) keeps randomly crashing and restarting under load

[Loose167]

Hi there,
Hoping someone here can help me troubleshoot this issue! My brother recently built his first PC, specs are:

5600x CPU + stock cooler
B550 Tomahawk Mobo
Corsair Vengeance RGB PRO 16 GB (2 x 8 GB) DDR4 3200
Corsair CX750F RGB, 80 PLUS Bronze Fully Modular ATX PSU
Palit RTX 3060Ti GPU
Crucial P2 500GB SSD
Crucial P2 1TB SSD

PC kept crashing in the middle of him playing Overwatch so told him to run Heaven and Cinebench, crashes on both. Temps seem fine although told him to install more fans so he now has three front intake, two top intake and one rear exhaust fan. Mesh Cooler Master case so temps shouldn’t be an issue.

Told him to do dump files -
WHEA UNCORRECTABLE ERROR
“A fatal hardware error has occurred. This bug check uses the error data that is provided by the Windows Hardware Error Architecture (WHEA). This bug check is typically related to physical hardware failures. It can be heat related, defective hardware, memory or even a processor that is beginning to fail or has.”

Tested RAM on memtest - no errors - not overclocked
Had him reseat his GPU and swap the PCEI cables just in case.

Gonna send him my PSU tester and some spare thermal paste so he can test PSU and reseat CPU. After that, I’m pretty stumped… Any advice? TIA

[veeg]

Hello

To me your weakest hardware is the psu.. But you can determine what is wrong by taking the parts out and reassemble those parts on some card board and power up.. Then see what happens..

[PeterOz]

win 10 or 11
did he download chipset drivers and install
What bios version

[Bruce]

@Loose167 - still need help?

[Bruce]

abandoned.