Question PC Wont turn on after several repair attempts, help!

[VoidBreakr]

I recently moved my PC into a new case, because my old case was kind of cramped. I moved all the parts into the new case and plugged it up exactly how it was before, but now it wouldn't turn on. it only made a very faint 'click click' noise, and nothing more. No lights, nothing.
I searched around for this problem, and the answer was almost always 'a faulty PSU.' I bought a new power supply, and still same thing. small clicking noise and then nothing.
I went back and triple-checked that i wired everything properly, and everything checks out, as far as I can tell
I tried buying a new motherboard, same issue. I'm in desperate need of help, I just want my PC back..

Thanks for your time.

Specs:
Motherboard: MSI MPG B550 GAMING PLUS
GPU: GTX 1080 Ti Founder's Edition
PSU: CORSAIR RMx Series (2021) RM750x
Case: Corsair 4000D Airflow
CPU: AMD Ryzen 7 5800X
SSD: SAMSUNG 980 M.2 2280 1TB
Ram: Team T-Force Delta RGB 16GB (2 x 8GB)

 

[ronzxcvb]

Did you check the power switch in the new case?

 

[--SID--]

There's a short somewhere. First test the setup on cardboard outside the case.