It seem you get a kernel crash. You should connect to serial console to get the kernel crash log. The network activity led is still not implemented yet.   You are using old U-Boot. It couldn't get the required device tree file. There was file renaming applied to Armbian 20.08.8 (released on 13 Oct 2020). You can do 1. Get serial console 2. When U-Boot appear, spam Enter key until you get U-Boot prompt (=> ) 3. enter this command    setenv fdtfile "rockchi