New 3DS XL booting up with sound black screen

so i got a new Nintendo 3ds xl with a curious problem. When i turn it on it apparently starts up (i hear the background music) but both screens stay totally black.
Does anyone have a suggestion what i should check?
I thought that the connection of the lcd screens to the mainboard could be loose, but then it shouldn’t start up right?

okay, so i read that this could be the reason of a faulty camera. i opened it up and checked the connection. seems like there was white stuff on it and the flex cable seems to be burnt. i disconnected it and started it up again. now both screens show me a picture and it seems that it works fine so far.
i just have to buy a new camera and see if the flex connector works or if i have to solder on a new one (which i dread as it is not possible without a microscope).