I've been using two versions below the current Ubuntu version because in the newer releases, my grandparents' old Dell Dimension 4500s is completely unusable. I forgot this until I recently upgraded to Karmic through the update manager, rebooted, and stumbled upon a system that had become a paperweight.

I run the Karmic CD, the boot menu appears, then I get nothing but a blank screen. The same happens on a Jaunty boot.

I'm really interested in upgrading this system, and if not upgrading at least getting it working again. Any help would be appreciated.