Tested the 24-pin connecter (PSU) with a paper clip while the was GPU plugged in

For context I was up until 2 in the morning fiddling around with building my computer and it wouldn’t turn on. I knew it was something to do with the PSU, it’s old and I got it from my cousin. This afternoon I tried testing the PSU by using a paper clip on pin 16 and 17 on the 24-pin connector, and I only realised late that the cpu and gpu cables were plugged into the motherboard. I freaked out and switched the power supply off at the power point. This may be important but I do have a surge protector and non-modular power 600w supply (if any of that matters).

I am wondering if my GPU is trashed after this. I don’t know what to do but I’m definitely ordering a new PSU. Thank you for taking the time to read this, any responses or thoughts would be appreciated