Tablet s9+ unlock screen is covered with a black screen

[Tablet_ya_jack]

When pressing the power button, the unlock screen doesn't come up.

When I press power and lower noise for some time  power off or restart comes up. Then when pressing any of the two the black screen stays.

Any idea?

Thank you 

[Tablet_ya_jack · Accepted solution]

Please look at this video https://youtu.be/Q9wQjuMC0C8 it seems like it is an old issue.  In my case the long holding of the power a d lower noise button helped already for a restart. The last 3 optare related to new.