Very few laptops have cables to connect the CD/DVD drive, they are
usually plugged directly into a connector on the motherboard. Worth
removing and plugging back in again to see if it makes any difference
but I'd doubt it. May be that the drive has failed and the wisest move
would be to replace it. Again most use a generic laptop drive with a
proprietary interface that unscrews from the old drive and is fixed to
the new one before plugging in.

BTW - as has been said often upgrading multiple times isn't a good
idea overall and you would be better off doing a clean install of
10.04LTS or 10.10 if you don't mind the regular upgrading.