I've never heard of a Pandora booting without showing some life on the LEDs in the hinge, even if the LCD isn't working7. Cable to the screen broke (and thus it boots, but no display). Cables will be soon back in the Dragonshop.
8. Somehow, the coil got loose (https://pyra-handheld.com/boards/threads/mainboard-repairs.74327/#post-1303391) during transit, when it was still on.