Question Asus x570-e no POST

[FinalMov]

Today I tried to Install the computer.

Asus x570-e
Amd ryzen 7 3700x
32GB ram crosair 16x2 3200 mhz
2070 xtreme gigabyte auros.
850w gold antec.

All the products brand new, I Build my computer for my first time.
I tried to get post for the computer and nothing.
I tried to do it with one stick and 2 sticks of ram.
I tried to reset the bios battery, I tried to pull out the battery for 5 minutes and then bring back.
I tried to get post with the graphic card and without him.
I tried different types of ports, hdmi, display ports.
And I got nothing.

First the q led display D6 and after it he switch it to 02.
The speaker beep like that.
1 long 3 shorts.
Please help me to understand if there is any other option except of send the motherboard to the states. Maybe something I miss or did something wrong.

Everything brand new and I don't want to lose all the money that I put.
Please help me I'm super depressed.
Thank you for your time.

 

[Phillip Corcoran]

The system must be POSTing if it's emitting BIOS beeps.

1long/3 short indicates GPU problem (no GPU detected).

Have you connected the power cable(s) to the 2070 graphics card?

 

[FinalMov]

Thank you for your respond .
The problem was missing 1 pin of power supply.
the computer and everything ok .
but right now every time that i turn on the computer, I still hear 1 long 3 shorts.
but the computer works fine .
any guess for the reason ?