Jetson nano 4gb not responding

hi everyone,
my jetson nano doesnt seem to work at all. i tried flashing different .zip files, changed sd cards, hdmi cables, monitors, power supplies. nothing. the screen stays black as if nothing in connected and it doesn boot. any ideas? i am very disappointed because i am overdue to my project assignment due to this.
the green light is the only sign there is to see if the dev board is “alive”

I moved your post to the Jetson Nano category. You will have a better change of getting a better response here.

Please have a host PC with Ubuntu 18.04 to install the SDK manger to flash your device via the JetPack.

Follow the guidance. Put your board into recovery mode and flash it.