NVIDIA Jetson Orin Nano not booting

I have a NVIDIA Jetson Orin Nano Dev Kit. It worked well for without any problem.
However, today I restarted the Jetson Orin from the console “sudo reboot”, it shut down, the fan turned of and nothing happened.
WHen cutting power, and connecting it again, only the green indicator light turns on, the fan remains off and i wont get a video out.
Does anybody have recommendations for fixing the not booting Jetson Orin Nano?