Build: Corsair 750W PSU 8gb ram 2400mhz ddr3 Intel i7 4790k AMD 7900xt

Hello everyone! Just to be clear, I know my cpu is not powerful enough for a 7900xt but my ryzen 5 7900x is currently being replaced, it died soon after building my new config.

I've been playing with this build for a month and nothing bad happened. Games like APT requiem, warframe or RDR2 worked fine.

A week ago I started playing the Witcher 3 and the problem started. The game runs fine but at some point the fans of the GPU start spinning at 100% speed and the screen turns black. It can happen between a few seconds or hours of gameplay.

I've tried reinstalling the driver and undervolting the GPU but it just doesn't cut it, although the undervolting allowed me to play longer before the problem started happening.

Since the issue started it happens with all my games. Before that I could play warframe all night without an issue but now it crashes after a few minutes just like it does on TW3.

Anyone knows how to resolve the issue?

Thanks!