Ubuntu – Black screen on upgrading to 15.04


Recently I upgraded from Ubuntu 14.04 to 15.04, and I get a black screen after the grub screen on selecting Ubuntu. I read a post that suggested I close the lid and open it again, and this actually solves the problem.

But I need to do this every time.

My machine is a HP Pavilion g6 with AMD Quad-Core A6-3420M with Radeon 6520G graphics card.

I tried several options, which I describe below.

  1. Removed 14.04 and reinstalled Ubuntu Gnome 15.04 from a bootable stick. Black screen appeared after grub screen. I tried to install proprietary drivers from Software Sources -> Additional Drivers. After this, even closing and opening the lid stopped working.
  2. Reinstalled 14.04.
  3. Ran upgrade from the command prompt using sudo do-release-upgrade
  4. This upgraded the system to 14.10, but this also produced the black screen. Closing lid and opening worked though.
  5. Brimming with hope, I ran the upgrade command again.
  6. Upgraded to 15.04, but black-screen remained, with the lid closing and opening still working.
  7. Based on another post, stopped lightdm, ran dpkg-reconfigure xserver-xorg, restarted lightdm. Rebooted machine. Nothing changed.
  8. Per another post, (did not keep track of the URL), I moved .local, .cache, .kde and .config to .local.old etc and restarted. The black screen still comes, the lid closing routine works, but my desktop looks messed up and the resolutions have gone awry.
  9. Tried another method. I had my home and root on different partitions, and I was leaving home untouched till now. I formatted both partitions and tried again from an ubuntu 15.04 ISO download, from which I created a bootable startup stick. The result is still the same: black screen, but lid closing works.

All my fonts and icons have become bigger than before, and the fonts are not sharp either.

The black screen is certainly a video/graphics problem and not a boot problem because I can hear the sound played by Ubuntu on bringing up the login screen.

Awaiting some help!

As per release notes of 14.10,

Machines with ATI/AMD video cards may be getting blank or entirely turned off screen at boot. The screen will switch on when the X server starts. If you need it to turn on prior to that, for example to unlock an encrypted harddisk hitting ESC twice should reset the video card to a working state.

Best Answer

My problem was finally solved after I applied the latest updates from Ubuntu a couple of days ago. I am unable to get hold of any version number to say which update I am running - if anyone has suggestions on how to get that, I'll be glad to post that information also.

Before applying the updates, I had tried out one more option: adding nomodeset to the Grub start-up script, as described here. That did not help me though. Now I don't know if it is a combination of both which works, but I don't want to play around to find out, as you can well imagine!

Hope this helps others too.

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