Black Screen on PinePhone with Manjaro

[Juron]

Hi forum.

I just received a new PINE64 Beta. Manjaro pre-installed. After a little playing, like installing ssh, x2goserver, upgrading and rebooting, the screen turned black. The K-logo can be seen. And sometimes the screen lights up and then turn black again. I rebooted several times. No change. I can SSH into it. What do I have to do to solve this?

Thanks in advance,
J.