mx2310u blank screen

i have a mx2310u with a blank screen. no light, nothing.

however the keypad and buttons seem to be working as it responds with a beep. and the machine powers up as normal. everything else seems to be rotating ie fusers running.

ive checked the connections on the panel, cable connectors have been reseated.

the controller seems to be working with lights flashing. sd card is present.

what can this be??