alfawise u20 problem

Hello
After uncloging the nozzle, screwing all again and launching printer a short circuit has occurred. During rebooting the screen remaining black and after connecting a new motherboard, screen remains white.I cant install firmware from sd card, so do u Have any idea what i can do to run printer again?

did you call tech support?

i write e-mail but dont got answer.
So I wana try to connect u20 to my pc and it's work but the extruder sensor show -10. now i must for everything works well i must buy new extruder and screen?