i installed the current "Armbian Bionic, mainline based kernel 5.4.y" image to my Cubietruck. Armbian was installed succesfully (from what I could see), all worked well, I could start the Cubietruck. I am connecting the Cubietruck HDMI to VGA input of the monitor.
Everything worked until I enabled (via armbian-config) the Desktop. Afterwards the Screen remained black (even though my monitor says to get video input signal). I can also login via SSH, means Cubietruck is running.
I studied: https://docs.armbian.com/Hardware_Allwinner/#how-to-reconfigure-video-output