Question PC not powering on after new PSU install. (Solved)

[GenericNameHerePls]

Hi, after trying to upgrade my GPU, I found out my old PSU wasn't powerful enough to run it, so I bought a Corsair RM750W PSU, however upon installation and checking all the connections were good I plugged it into the wall and the motherboard LEDs turn on like usual but the power button doesn't power on the PC though it does briefly turn on the fan LEDs for a split second, I have tried shorting the power pins as well with no luck, I have tried reseating the ram and GPU, and I have tried to switching back to the old PSU only to have the same results as the new one.

 

[faalin]

Full system specs with make and model please.

What is the old PSU? Did you switch out every cable for the new ones that came with the Corsair PSU?

 

[GenericNameHerePls]

Full system specs with make and model please.

What is the old PSU? Did you switch out every cable for the new ones that came with the Corsair PSU?

Hi, I've got 8x2GB of Corsair Vengeance DDR4 ram, a Ryzen 3 3300x, Asus Prime A320m-k, MSI GTX 1080 Armor, The old power supply is a Kolink Core 500W which isn't modular so yes I did swap out every cable I've had it since around 2018-2019 so it's a few years old at this point too

 

[GenericNameHerePls]

Right so update, turns out I had accidentally somehow got the mobo to touch the case which was causing something to short.