DVD-RW Unit Replacement

I tried to find any authorized tech support of this Lite-on Clone but they refused give me a tech support so any one can tell me how and where can I get the multiplayer DVD-RW internal drive to replace the original one, What model or part number is it?
I went to the electronics repair shop and they checked why the DVD Recorder do not record and play CD or mp3 and they told me I need change the unit but they can locate the part, I will appreciate your help.