Optical Drive Plays Dvds But Not Cds


I have a Powerbook G4 with a CD-RW/DVD-ROM. Out of the blue, my computer would be unable to read a CD. It would just spit it out after 5-10 seconds. However, it will read DVDs of any kind no problem. Is it necessary to replace the drive, and if so, is there a drive out their you recommend that I can buy online and install myself. Thanks.