Question B550 Gigabyte Aorus Elite AX v2 doesn't boot ?

[M_Mustafa]

Specification:
B550 Gigabyte Aorus Elite AX v2
CPU: Amd ryzen 5 5600X
GPU: Asus Dual RTX 3060 Ti
RAM: Vengeance LPX (2x8)
SSD: WD Blue SN570 NVMe
PSU: Aorus P750W 80+ Gold

When I turn it on I got a black screen so I checked all the cable connections and parts but all things are fine.
Then i tried to update bios but same problem still exist, motherboard not booting.

 

[Lutfij]

Welcome to the forums, newcomer!

PSU: Aorus P750W 80+ Gold
How old is the PSU in your build? Did you perform an upgrade prior to the issue cropping up? As a side note, what was the last thing you did before the system ended up this way? Did you try clearing the CMOS, after disconnecting from the wall and display?

 

[M_Mustafa]

this is my first build. and PSU is is new

At first i was using msi b550 A-pro and all things working fine but I found an issue in ethernet adapter so i replaced it with b550 aorus elite ax and from this moment my pc cannot boot

so I tried
1- check all cables and parts
2- update bios
3- clear CMOS

but still not resolved