I have a new 7900xt that turns itself off when launching certain games, so far I have found it happening to "Castle Crashers" and "Vampire the Masquerade Bloodlines" (2004). I tried to reseat the gpu and ram. I also unplugged and plugged back in the psu power cables, I have an 80 plus gold rated 850 watt power supply (I forget which) and most things are fine. I plugged my second monitor into my motherboard so that I can use the integrated graphics when this happens. at one point I ran a driver update, which turned the gpu back on. these games should not be pulling to much power for the gpu to have issues. I updated graphics drivers, motherboard BIOS, and Windows, but this still happens on these certain games.