The cd/dvd drive installed in my laptop does not work.

Please read this post.
http://www.fixya.com/support/t3185554-m_using_lenovo_y500_laptop_hitachi_ht

it has the same cd drive which you are talking about. the problem is only with the drive. they also do not provide any firmware to update it. there is no filters problem. the problem is mechanical which is something you cant fix. these are chinese made drives, just use and throw. so, its now time to throw. there is no point banging your head, becasue i already banged a lot for this issue, and please dont replace your drive with sony optirac, it will also give you the same problem. all the best.
the drive which you talked about is the same i had originally on my computer. i also tried myself to update the firmware of the drive but no go. it still did not work. so i checked the functionality of the dvd drive. what is the technology of dvd drive and i found there are 2 lenses in the drive to read cd and dvd. if one fails it will read only 1 type of cd or dvd then. presently my computer has 33rd optical drive which is again matishta. it is still working, i dont know how long will it work. but touchwood its working now. so all i can say after such a bad experience is that its just a luck. regarding which optical drive to get now? you can get any one. its just the name, technology remains the same. like a lot of different people. but blood remains the same. so name doesnot matter. But i strongly say drives with SONY OPTIRAC are the worst drive, Never buy that. other than that you can get anyone. hardly matters.