Why my screen is black?

My samsung falaxy s3 fallen frm my hand , not from a more height , but battery pulled out . So when I fixd d batter y and started d fone it was fully black . All other fxns working ok , touch ok and all are ok . But screen is full black so nothing to use fone now . Can u guide me what problen is there evn d glass from outside is also ok , not found any crack . What problme here may be . Digitizer problem or what u suggest me .