As stated in the title my PC suddenly completely shuts down as if i would lose power. I am pretty sure that it is the Power supply but i wanted to ask if it even is possible for a CPU or GPU to just let the whole computer lose electricity before i buy a new PSU
I had this happen recently as well. Could be the CMOS battery on your motherboard. It should be trivial to check if replacing it fixes the problem before you commit to buying a new PSU.