ryzen9 Pc suddenly restarts when i try to play some games

[Cotobakan]

Hello everyone, i have a friend that has a Ryzen 9 5900X running 4,5mhz and 1,4v average. She uses Maya, Zbrush, plays Overwatch, Battlefield and some other demanding games but when it comes to try new or beta games her pc suddenly restarts (Games like ''The Cycle: Frontier'', ''Century: Ashes of Ages'' and ''Chivalry 2''). We saw that she has some ''Kernel-power'' issues but we don't know if it's a Power supply, Cpu, Gpu or Ram problem because the Cpu and Gpu don't go further than 68-70°C(158°F) even on stress tests. Hope someone can help us to figure out what's the issue.
Specs:

G750M cooler master 750w 80 PLUS Bronze power supply

MSI Rtx 2060 Super 8gb
Ryzen 9 5900X

ASRock B450M Steel Legend

Water Cooling
16Gb(2x8) Ram 3600Mhz

[Rauten]

Quick idea, have you tried to crash it on purpose? You say you have stress tested the CPU and the GPU, but have you stress tested both at the same time?

Prime 95 full blast for the CPU, Furmark for the GPU. If it's an actual problem with the power supply, that should take it down.

 

You say the PSU is a 750W Bronze unit, but you don't say brand or model. Do you not know them? Is the PSU a no-name unit?

[Cotobakan]

Sorry for the power supply brand missing, its a ''G750M cooler master 750w'' and thx for the idea, we should try that soon and i'll let u know how is it going

[Cotobakan]

Well, we tried with another PSU and it worked fine... So the solutions will be changing it.