I have noticed that Dell Dimension DVD/CD drives often times go bad if you don’t use them. Or perhaps even with use they just tend to go bad. I have had over 20+ Dell Dimensions ranging from the 2400 to the 3000 to the 8000 and what have you and almost all of them always have two drives and for some odd reason or another both drives die. I cannot boot from a CD using either. I go and put in a new optical drive and sure enough I can boot just fine.
It’s very strange and I wonder if it’s just crappy drives to begin with or if it is something else. I believe I have, in the past, tried hooking the two drives up to an external enclosure. I do not believe I had any luck with using the drives that way either. Kind of sucks as both drive eventually just go bad on their own.