Question PC doesn't turn on most of the time when the power button is pressed

[tricks243]

Specs:
AMD 5900x
ASUS ROG CROSSHAIR VIII DARK HERO
EVGA 3070 TI
Cooler Master V750 SFX Gold Full Modular
Liquid cooled system

What am i missing?
This is what I've been doing to fix the issue until next reboot:

1. Flip PSU switch to off and wait for LEDs to turn off.
2. Flip switch on power strip.

Things I've done to find the cause with no conclusion:

1. Re-seat all PSU plugs into MOBO/PSU
2. Re-seat RAM(IDK WHY I JUST DID)
3. Re-seat GPU and GPU riser cable
4. Check for leaks on components
5. remove PW/reset pinouts and bridge PW pins

P.S. there is a power button on the MOBO and even it has the same issue with not turning on the MOBO without discharging power.

 

[Cem Goker]

I would start looking for loose/missing screws on the motherboard as well as investigate the standoffs for the motherboard. If it still fails to power on, then I would remove the components and test them without the case.