My LG DVD player DP9911P can't play any disk!

Hello,
I have the LG DVD player DP9911P. And someone accidentally drop it last night but nothing happen apprantely. But the problem is that now I can't play any disk coz whenever I inserted the disk, any disk, it is just showing either no disk or check disk. But when I press onto the menu or title and some other buttons, they are still showing. Only that showing no disk or check disk to all the disk being inserted. I think there might have some problem with Len? Anyone please help me to solve it out coz I dun want to buy new one but jzt want to repair. Thx lots!