I use Ubuntu as my main desktop operating system, together with Gnome Fallback/failsafe, because I dislike Unity and want to keep my Gnome 2 desktop.

This might not be relevant to the problem, but when I upgraded from 14.4 to 16.4, I lost my sound card. When the computer booted, I would get the Ubuntu drums, but once I logged in, the only sound I had came out of my USB headphones. I no longer saw my Intel HDA soundcard listed in the gnome sounds settings.

After a lot of digging I eventually worked out the cause of the problem, and a temporary fix. Long story short, pulseaudio couldn’t detect the sound card, because Ubuntu have changed the way it’s loaded.

You need to therefore reload the detection libraries and restart pulseaudio, run the following command:

Now, I have a startup script that I run as part of my user login to set up my desktop environment and kick of my development environment, so it was enough for me to put this command in that script.

You will probably want to make sure you load this module in your pulseaudio init scripts. Anyway, hope this helps.

So, after I fixed the two screen problem I was having with my Ubuntu setup, I started getting an odd flickering.

This flickering didn’t affect the whole screen, rather it seemed to be something to do with window repainting, and it became even worse after I updated to 14.04.

I run a slightly non-traditional configuration, in that I run Gnome2 fallback rather than Gnome3 or Unity, therefore this probably won’t effect a lot of people, and is probably why it persists.

After a bit of digging, I discovered that this is actually a compiz issue. Here’s a summary of the fix:

Fixing the flicker

  • Install the compiz settings manager: apt-get install compizconfig-settings-manager
  • Scroll down to “Workarounds” in the “Utility” section:

compiz-1

  • Select “Force full screen redraws (buffer swap) on repaint”:

compiz-2

Once this is done, your windows should repaint as normal.

So, I recently got a notification that my Hardware Enablement Stack (HWE) was no longer going to be supported, so I had to perform an upgrade. I didn’t have time to move to 14.04, so I just did the HWE upgrade.

Unfortunately when I rebooted, I no longer had 3D support, and worse, my twin monitor setup was no longer supported (or rather, both monitors were active, but showed the same thing!).

Diagnosis

I am rocking a NVIDIA GeForce GT 610, which, although it’s a basic card, doesn’t seem to be supported very well by Ubuntu’s native Nvidia drivers. When I ran nvidia-detector, no cards were found.

Since my card was working before, I figured it was probably just a driver problem.

Solution

The solution I used for this was to update the Nvidia drivers to use the Nvidia proprietary drivers. Here’s how…

  1. First, visit the Nvidia website and use the wizard to download the correct driver bundle for your card.
  2. Hit Ctrl-Alt-F1 to enter a console
  3. Uninstall the existing Nvidia drivers: sudo apt-get remove --purge nvidia-*
  4. Move the old Xorg config out of the way: sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.orig1
  5. Stop X: sudo stop lightdm
  6. Run the NVidia installer (Note, you may need to reboot and re-run steps 5 & 6, as the installer may have to disable some kernel modules). Save yourself a headache, and be sure to build the DKMS module, so that changes aren’t lost when ubuntu updates itself.
  7. Reboot

All going well, you should now have working Nvidia drivers with two screen support!