I just got a new raspberry pi 4 model B. I used it twice and it was working perfectly fine. But on the third time, when I tried to turn it one, I have the rainbow screen then the screen which says "for recovery hold key shift" (or something like this) and then I have a black screen. I don't understand because I have a new hdmi cable which came with the raspberry pi (I tried two different cables) and then I have as input a mouse and a keyboard. I tried with two different screens as well.
What can the problem be ? Please help me