TripleR

Hello I am new at the forum. My english is not good but i can understand all :) I have a Magicsse n5 android box (S905X) and i like to install Armbian on it (on a micro sd card) I have done everything in the manual but I'm only assigned to the user and assigned root and then linux should start. But it does not do it, it only flashes in the top left of an arrow. I tried it with this file "meson-gxl-s905x-p212.dtb" but it does not work .... Do you have any idea why it is not working? Thank you :)