Black screen after reboot

Hello everyone,

I have a problem on my Rock 5b 16GB RAM with the version of ubuntu 20.04 (

Indeed, I have a problem updating Ubuntu when I perform the sudo apt update command and I have the following error message:

E: The repository ‘ 18 focal InRelease’ is not signed.

I explored the forum to find a solution and so I made the following orders:

export DISTRO=focal-stable
wget -O -$DISTRO/public.key | sudo apt-key add -

The update and upgrade is done properly without the error message after it. However, when restarting the Rock 5, it displays a black screen and no controls enable the machine.

So I reinstalled Ubuntu on the micro SD without performing an update of Ubuntu, the computer works. The use of the Rock 5 is therefore far from being optimized because many manipulations have to be done to install my working software that works in the Ubuntu shell.

Thanks for your answers

Try this image instead its fully updated // gpu wise and everything so if then there you have black screen issues it cuts the middle men it can also be your screen or even a board issue. (But this is my suggestion)
See if it works: Rock 5B - My experience Armbian Afterburner image

Thanks for your reply, I’ll try that and let you know if it works.

Good morning,

I just tested your solution but it doesn’t work with my usage. Indeed I need to use ubuntu 20.04 in order to be able to install my different software.

Do you have a solution to use ubuntu 20.04 and be able to update without my rock 5 crashing?

Best regards