Just tryna play some games with my buddy but everytime he boots a game it freezes and crashes. He's replaced like every part of his PC and updated all drivers. I know he's also tried undervolting. He said when he got the new graphics card it also got worse? I'm trying to help him not waste anymore money.

Ryzen 7 5700G EVGA RTX 3060 XC 12GB ASUS TUF X570 Plus Corsair CX750M Corsair Vengeance LPX 32GB x2

Also did it on; Ryzen 7 2700x MSI B450 Gaming Pro Carbon AC MSI Radeon RX580 Armor Corsair CX550M (Same RAM)

RX580 would freeze, then black screen, then shut down games. Sound would continue until just before the black screen came back. Did it one both mother boards/processors/power supplies

RTX3060 will crash RuneScape at start up and Halo Infinite at match start.

Tried under clock and in MSI Afterburner, Riva Tuner, and under volt on BIOS

Edit: THANKS! It was the ram guys. I appreciate all the help.