Question PC turns on, no signal to monitor/peripherals, no post, fans spins, on board rgb lights up

Nov 25, 2021
Sorry if this is in the wrong section, but I figured since it's happening to the whole system, I put it here.

Last Monday, I came home, turned the PC on and did some stuff and let it idle for a few hours, made dinner and came back to:

No display to monitor
All RGB frozen in circulation on MB, AIO, keyboard and mouse
PC not responding

I then hard shut down the system thinking "Ok, maybe it crashed itself or Windows crashed itself.". I turned the power button and the PC refused to post (not the mb name flashed), on board RGB lights lit up, all fans spun, and keyboard and mouse RGB wasn't on. I have since then tried several troubleshoots:

Put display cable into HDMI outlet on MB
Fully tested monitor on my older computer, works fine
Made sure all connections were secure inside case
Reseated RAM several times, one at a time to see if it was a bad ram stick or slot
Reseated graphics card into second slot to see if it was a bad slot
Replaced CMOS battery completely
Fully tested PSU, working fine
Fully checked everything I can think of

I have bought a brand new motherboard coming to the conclusion it was the motherboard that fried. I have no way of testing the CPU as my older computer is an old AMD socket.

ASUS Prime Z390-A (bought in very good condition off Amazon two months ago)
Intel Core i7 9700K
NVIDIA GeForce RTX 2080
ASUS ROG Strix LC 240
Trizen Z 32 GB Ram