Question PC randomly shut down while playing dota 2 and won't boot anymore


Nov 7, 2014
i7 7700k
16gb ram
Gigabyte gaming 7 z270x motherboard
gtx 1080 ti
RM 750x PSU

When i turn on the PC, the PSU clicks and the rgb on my ram turns on but nothing else (no fans, no motherboard light, no error code on motherboard display)

I tried unplugging the CPU's 8pin power connector then the motherboard lights up (but obviously ends up in a boot loop since CPU doesn't have the required power), the Same thing if I leave the 8pin connected but remove the CPU or remove both CPU and 8pin. As soon as the CPU is plugged in, then the PSU clicks and no power.
Also tried removing everything and gradually plugging each item individually but again no dice as soon as the CPU is plugged in

Is it my PSU, CPU or the mobo which is dead? I was thinking of recycling my PSU for a new build with zen 3 but I am scared that in case the PSU is the problem here it would kill that build

Also, I cannot use another CPU to test because if it dies then I am screwed (since it's my brother's and if it dies we cannot go to the service centre since it's in a COVID red zone)

I would appreciate any help in diagnosing the problem without risking any components