From another thread (here) it seems that the drive is not replaceable in that model.
I have had luck fixing some recent Liteon computer drives with your problem by replacing the rubber belt that opens the drawer, but I'm not sure how feasible it is with this model. If the belt is easy to get to, see how flexible it feels - when the belt has stiffened, it doesn't pull as well.
My source for replacement belts is MCM Electronics, with a very good selection, though their shipping is a bit expensive.
P.S. If you can improve the title on this thread it may attract more of the Liteon experts.