When i insert a cd into dvd/cd rom, it doesnt read the cd, i bought them all new some time ago but having problem in both roms (dvd & CD). The light kept blinking as its trying to read the cd's but it ends up with nothing being read. Also i heard some crunching voices from dvd rom while cd is inserted.

Anyone can help me out? Does my roms require their lens to be cleaned? or what?