My Rock 4C+ doesn’t boot with every image I tried. Those images come from the Radxa Build repo or from the Radxa download page.
I use the alimentation shipped with the SBC, I tried with several SD cards, I also tried to flash with BalenaEtcher on Linux and with Rufus on Windows, but the Rock doesn’t want to boot : there’s only a green solid light, no blue one, and no signal is sent through the HDMI ports.