Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I updated 12.04 this morning through the update manager (can't remember what it was, but it was only one thing) and everything was fine up until a few minutes ago when my screen changed and began flickering a partitioned white, red and green. I can't access any of the terminals so I'm not sure what to do.

Any help is appreciated.


Edit: I'm running a Dell Studio 1558 which has an ATI Mobility Radeon HD 5470

share|improve this question
Please provide more info like video card, etc. – Frantique Jun 13 '12 at 15:45
Updated info on the main thread. – Timsworth Jun 13 '12 at 16:05
Do you get the same result if you attach the system to a different screen? This sounds like hardware failing to me. – Elder Geek Mar 10 '15 at 17:17

Create the file (as root) /etc/modprobe.d/radeon-kms.conf, and add the following line:

options radeon modeset=0

Reboot, and see what happens. It should fix your problem.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.