Thank you for your input, but this method has been confirmed not to work with HD5xxx cards (see the ubuntuforums thread for some reports on this). I am happy that you managed to fix the issue on your notebook, though!
@northar, maurice_o5, geoff-wong:
The tutorial above should work fine with your cards (HD6xxx and 7xxx series).
@everthonvs:
Thank you for your input, but this method has been confirmed not to work with HD5xxx cards (see the ubuntuforums thread for some reports on this). I am happy that you managed to fix the issue on your notebook, though!
@northar, maurice_o5, geoff-wong:
The tutorial above should work fine with your cards (HD6xxx and 7xxx series).