Jetson xavier nx not work

The core board cannot work normally and cannot be started. The power on voltage is 12V and the current is 1.23a

How did you tell the board is not able to start?

I use the third-party backplane and brush it into the system given on the official website (in win10 state). After power on, the screen is black. At this time, the voltage is 12V and the current is 1.23a

Please dump the log.