Which version of Ubuntu did you install?
What kind of install disk did you use, live for example?
What else is on the laptop? That is, is this a dual-boot?
Do you see the grub boot screen?
Offhand, this sounds like video drivers, but I've only seen that trying to run the install of a 6.06 live CD. I had to run Ubuntu in safe mode to run the install. I have an Acer Travelmate 630.
You may have to boot into init level 1 and poke around with help from someone who knows far more than I about rescuing and hardware.