the dvd player does not open nor closed?

Hello,

The dvd player is playing fine. One day, I open to insert a new movie, closed it and it did not play. The screen went blank. I tried to open in order to remove the disc but it did nothing. I turned off the player and turned on, still did not work. Finally, I took the cover off and able to retrieve the movie. But the problem was not fixed. Please help. Thanks.