Here's some problems that you may face while using your DVD burner. Take a look, it may solve your problems.
However, most of the time damaged DVD burner can't be repaired and should be replace by a technician.
http://forums.cnet.com/7723-7586_102-574917/what-s-causing-my-cd-dvd-burner-to-suddenly-stop-working/?tag=nl.e497&s_cid=e497
