Jetson TX2 failed boot after flashing L4T 32.1

I flashed my TX2 by flash.sh manually and sdkmanager, but both of them failed boot. The monitor showed some information and it goes dark.

Very likely the TX2 is otherwise running normally, but video configuration is not working.

If you use CTRL-ALT-F3 keystroke combination, do you get a text console? Can you ssh to the TX2? Even better yet, can you check via serial console? See:
http://www.jetsonhacks.com/2017/03/24/serial-console-nvidia-jetson-tx2/

I have resolved this issued.

Basically, I just pulled out the HDMI wire from TX2 and reconnected it to the monitor after one minute waiting. Then the monitor showed the System configuration wizard so I can continue.

However, after the sdkmanage finished all the processes(flashing the OS, install the develop component), I still cannot boot up the board. So I used a smaller monitor using VGA to HDMI adapter to connect Jetson TX2. And all the things work.

Normally VGA is unsupported. HDMI and modern cables support a method to query the monitor and ask for its stats in order to automatically perform video setup. VGA literally cuts that wire. In a case where VGA works it is because the video is already in a compatible mode, or else the video has fallen back to a default and the VGA happens to be able to use the default (meaning you got lucky). So although this may work for now, do expect that at some point a change to the system might result in VGA failing again (you might not be as lucky once something changes). This is ok if it is just for finishing flash, but you might still want to find out why the HDMI doesn’t work.

FYI, the driver itself has a limited set of supported modes (it’s actually a lot of modes, but not as many as a desktop PC…in particular nothing interlaced is supported). If the modes listed by the monitor when it is queried are not in the list of the drivers supported modes, then display will fail.