Blank screen after suspend/hibernate on 14.04

Killing the process light-locker (discovered by using xwininfo) helped us temporarily, then uninstalling light-locker with dpkg --purge light-locker light-locker-settings fixed it more permanently.

We are using Gnome 3, so this might not be a solution for everybody.

(In general, there's probably a process displaying a black screen that you need to kill; try to find it!)

Which kernel are you using? Check this with uname -r. I am not a fan of the AMD proprietary drivers on Linux. I find lots of issues with them. I prefer running the open source drivers and newer kernels have many new fixes and features for AMD graphics. You can take the OPEN SOURCE ROUTE, or the PROPRIETARY ROUTE.

OPEN SOURCE ROUTE

If you are using 3.13, then try the newer 3.16 kernel

sudo apt-get install --install-recommends linux-generic-lts-utopic

or try the entire Utopic LTS Enablement Stack which is better...

sudo apt-get install --install-recommends linux-generic-lts-utopic xserver-xorg-lts-utopic libgl1-mesa-glx-lts-utopic libegl1-mesa-drivers-lts-utopic

If you are already running 3.16, then try removing the Utopic LTS Enablement Stack

sudo apt-get remove linux-generic-lts-utopic xserver-xorg-lts-utopic libgl1-mesa-glx-lts-utopic libegl1-mesa-drivers-lts-utopic

If none of this helps, you can try the newest stable kernel. This is a bit more tricky, and could cause some issues, but I have been running the linux 4.0 kernel on Ubuntu 14.04 for a while now with no issues.

mkdir linux4-0-4
cd linux4-0-4
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0.4-wily/linux-headers-4.0.4-040004-generic_4.0.4-040004.201505171336_amd64.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0.4-wily/linux-image-4.0.4-040004-generic_4.0.4-040004.201505171336_amd64.deb http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.0.4-wily/linux-headers-4.0.4-040004_4.0.4-040004.201505171336_all.deb
sudo dpkg -i linux-headers-4.0*.deb linux-image-4.0*.deb

After installing or removing any kernels, you will need to reboot in order to test them.

PROPRIETARY ROUTE

You can install the AMD proprietary Catalyst driver fairly easily in Ubuntu 14.04. Simply run

sudo apt-get install fglrx
sudo apt-get install fglrx xvba-va-driver libva-glx1 libva-egl1 vainfo
sudo amdconfig --initial

If you are using multiple AMD graphics cards or AMD dual graphics (i.e.: notebook users), use:

sudo amdconfig --adapter=all --initial

After installing or removing Catalyst, you will need to reboot in order to test.

I had this problem that Ubuntu could not load after upgrading from 12.04 to 14.04. After running startx there was just a black screen. I fix it by going to recovery mode and just picking Repair broken packages and check all file systems, but I think only the first option will work.

Did you turn off the power of the Radeon graphical device? Because I did it and what you describe here was what I experienced. I canceled the VGA power turning off and the standby exit works again for me.