Greetings from a first timer, I have a 1.5 year old iMac 600mHz with a slot type CD bay that will not read/write CD's anymore. It accepts a disk, makes some humming noises for a few seconds, then ejects it. Have tried numerous disks with the same results. Also tried using iTunes to try and burn a disk but the blank also was spit out. Tried rebooting with extensions off to check for software glitch. So I'm thinking it's a hardware problem and I'm wondering how hard it is to replace the internal CD-RW drive assuming it is unfixable. Or should I just get a new external drive. Any thoughts before I go to my local Mac fixer?