if it doesn't show in your drive manager, then it's not going to show in device manager. If it's getting power, yes, it's connected, but for some reason it's not being read by the motherboard. This could be due to a bad cd drive (which is the best case) or a bad motherboard (worst case). I seen a load of Dell M90's with this issue, but I don't know what model you have, nor if it's under warranty. That would be something else to talk to you friend about.
I would try removing the cd module, and then pushing it firmly back in, see if the system recognizes it. Outside of that, not much you can do in this case except try an identical cd drive to see if it's the drive or the
mobo.
thanks,
v