Apart from the fact that you can open the drive as shown above, when you get it open take a look & see if ther is a small belt near the motor that opens & closes the sled. you might get away with a quick clean or it could be that it requires replacing. Also clean the pulleys, they aquire a film that helps make the belts slide. Use a cotton bud, also once the belt is off, you can play with the door open/close button and a cotton bud to ensure that the motor is turning. Don't do it with the belt in place.