So I left my pc running (which I do almost constantly) and took my dog for a walk (30 minutes?), and returned to find that my pc had crashed to black, with lights still on, and I could smell something odd coming from the GPU. The lights on the motherboard were still on. I switched off the power on the surge protector, back on and tried to boot it - sort of a scratching sound from the GPU, the fans twitched, then nothing. No lights on the motherboard. I did some frantic googling on my phone, decided to try booting without the GPU in to see if its the power supply. Killed the power again, took just the GPU out and tried it again, booted just fine.
So I have to assume its the GPU, right? But I can't see any burn marks on it, the smell seems to be coming from the power port on it but none of the ends, either on the cables or in the sockets are blackened, and I haven't had any problems with performance with it. The fans were acting up last month, they were making a grinding noise, but that went away, I assume from dust that got worked out on its own. I can't smell anything coming from the power supply. I think the GPU is 3 years old? I don't have any old components to switch in to try, this being the first pc I've built.
Any insights, duders? I worry that the power supply may also be boned and burnt out the GPU, but with no signs leading up to it, I don't really have an idea of what's happened.