Hi,   I face the same issue, on a recently bought a Rock Pi 4B v1.3.   Steps followed:   1. Downloaded official (Radxa) Ubuntu Server Bionic  as well as Armbian Buster Desktop (Armbian_5.98_Rockpi-4b_Debian_buster_default_4.4.192_desktop.7z) via torrent.   2. Wrote both images to different SD cards (Samsung Evo Plus Class 10) using dd. The one with Radxa Ubuntu boots, but Armbian buster does not. The red Led keeps blinking, no output via HDMI. Rewrote and