I have an old 15" iMac G4 (nice computer). It seems that the CD drive doesn't work, when I put in any CD, whether audio of data it won't read. I assume I need to replace it. Where can I get a replacement ideally one that will read CD and DVD. I don't need to burn anything, but reading DVD would be helpful. My friend says that you need a special drive to fit into that housing. I know that the actual replacement process is a little annoying and needs heat sink paste. Thanks for any advice.