it happens with all 7th gens i wanna believe, when you drop it it kinda like makes the phone panic and renderitself useless like some sad lil puppy on the side of the road. just hold the power,volume, and home button down which resets it and when it powers back on it may flicker but thats only because the LCDs were a bit burned for a bit but will ultimately go back to its normal state within a few hours. it depends on how long the phone was in that state. the longer the phone has the lines the longer the flickering and the lines will appear on the screen. I dont know what causes this but if anyone knows please tell me. im very curious