Rample's screen goes blank

Yesterday happened something really strange to my Rample.
I was trying to assign midi channels and suddenly the screen went blank.
Now when i move menu knob, it only shows samples kits names, but cannot select anyone of them, cant exit menu, cant enter assign menu etc etc…nothing.
Also the 2 dots in the hight right corner disappeard.
Now i basically cant youse Rample, no sound, no screen.
I also tryed to change power supplier for the unit.
What is going on? :frowning:
thank you