No issue with USB 2A, headless or not.
No issue with barrel supply 4A, connected to HDMI screen. (It does complain about the last failure, and want to report to Ubuntu.)
When I use barrel supply without HDMI output, Jetson nano will
- green light on
- boot up for a few secs
- fan on
- power off
The WiFi modular was never light up. It will repeat so unless the following is done.
What I did is,
- attach an HDMI connector (doesn’t matter if there is output device), start it up (it will fail as described above).
- detach the HDMI connector, it boots up successfully.
Not an expert on Linux, so I didn’t spend the time to diagnose through UART.