I just bought a Rock Pi4B v1.4 recently.
I tried to boot it with https://dl.armbian.com/rockpi-4b/Debian_buster_default_desktop.7z and https://dl.armbian.com/rockpi-4b/Ubuntu_bionic_default_desktop.7z
However it was all in vain.
I also had tried SDCard and emmc but none of them worked.
I face the same issue, on a recently bought a Rock Pi 4B v1.3.
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