I know there is already a ATI for linux thread, but the 5xxx series is a special case because it won't work with the liveCD. Thankfully, it's a very simple fix.
THE PROBLEM
With the release of catalyst 10.4 drivers for Linux, we finally have support for the latest graphics cards; however, if you've tried to boot the liveCD with a ATI 5xxx series card, the purple ubuntu load screen will load and then your screen will go black.
THE FIX
If you're using the liveCD (I did not, so this may not be true), press F4 and choose safe graphics mode.

This will force the vesa drivers to load.
If you're used unetbootin to make a liveUSB, the boot loader screen looks similar to this:

What you want to do is press [Tab] to edit options.
This will give you a whole bunch of kernel parameters that we're not concerned with. Leave everything alone EXCEPT you need to add
to the end of it. There should already be the "--" part so just add "xforcevesa".
Both of these option will get you booted up. Now install like normal, reboot, and THEN install the fglrx driver. Reboot again, and you're good to go!
Enjoy!
THE PROBLEM
With the release of catalyst 10.4 drivers for Linux, we finally have support for the latest graphics cards; however, if you've tried to boot the liveCD with a ATI 5xxx series card, the purple ubuntu load screen will load and then your screen will go black.

THE FIX
If you're using the liveCD (I did not, so this may not be true), press F4 and choose safe graphics mode.

This will force the vesa drivers to load.
If you're used unetbootin to make a liveUSB, the boot loader screen looks similar to this:

What you want to do is press [Tab] to edit options.
This will give you a whole bunch of kernel parameters that we're not concerned with. Leave everything alone EXCEPT you need to add
Code:
--xforcevesa
Both of these option will get you booted up. Now install like normal, reboot, and THEN install the fglrx driver. Reboot again, and you're good to go!
Enjoy!







