Jtdcftul

I am a technology enthusiast and try to taste all new technologies (wherever possible) coming in Computing world. So, naturally, when Canonical released 16.04 LTS on 22nd April, I downloaded 16.04 LTS(original ISO Unity) and tried to install (completely cleaned the 128 GB SSD with GParted boot disk and attempted to fresh Install, "single boot").

I used USB flash to boot (UEFI mode) Ubuntu. When "Install Ubuntu" option came on the screen and I pressed 'Enter' but screen went blank and never recovered any graphics to show in the monitor screen. But, looking into the Hard-disk indicator light I could assume that system is busy but 'NO DISPLAY' on monitor screen.This was partly informed guess as I already read few articles about fglrx/catalyst/AMD/ATI Opensource driver.

Next, I installed KUbuntu 15.10 and when Software manager asked for Upgrade into 16.04 LTS, tried to upgrade. During upgrade I got few messages from Installer and noted them down for future reference.
"Replacing /etc/default/rcS";
"Removing 63 packages from /usr/share/sddm/scripts/Xsession";
"setting up xserver-xorg-video-amdgpu".
I chose everything as 'YES' in the above cases.
Finally, upgrading was completed and system asked for reboot.After reboot, Ubuntu 16.04 LTS never came up on the monitor screen (it just went blank, same like the fresh install).Below is the hardware in my system.

So, my question is: Is it not possible to install 16.04 LTS in my system?

Below is some information about the system:

kubuntu1404               

    description: Computer

    width: 64 bits

    capabilities: vsyscall32

  *-core

       description: Motherboard

       physical id: 0

     *-memory

          description: System memory

          physical id: 0

          size: 14GiB

     *-cpu

          product: AMD A10-5800K APU with Radeon(tm) HD Graphics

          vendor: Advanced Micro Devices [AMD]

          physical id: 1

          bus info: cpu@0

          size: 1400MHz

          capacity: 1400MHz

          width: 64 bits

      *-display

             description: VGA compatible controller

             product: Trinity [Radeon HD 7660D]

             vendor: Advanced Micro Devices, Inc. [AMD/ATI]

             physical id: 1

             bus info: pci@0000:00:01.0

             version: 00

             width: 32 bits

             clock: 33MHz

             capabilities: vga_controller bus_master cap_list rom

             configuration: driver=radeon latency=0

Currently, I am running KUbuntu 14.04 LTS.

Yes, it is possible to install Ubuntu 16.04 LTS on this system. Canonical has has discontinued support for the proprietary fglrx driver but the existing radeon/amdgpu drivers are sufficient replacement.

Note: I had "vanilla" Ubuntu 15.10 installed on this system from USB drive and then upgraded to 16.04 LTS.

I have the same issue with A6-5400K (MB Biostar A55ML2, VGA output on the MB). I have upgraded from Xubuntu 15.10 to 16.04, and all I get after boot menu is black screen. Sometimes picture appears after an hour or so. First I thought there might be some HDD error, so I have attached same HDD to my other PC (A10-7850K, Asus A88XM-Plus, DVI and HDMI outputs on R7 260X), and everything was fine.

It is the same with live disk (from USB drive) – doesn’t work on A6-5400K, works on my other PC.

fglrx does not support the newer A10 series APUs, as they were released after the final fglrx release (15.12).
fglrx DOES support the older A10 series with Terrascale gpus (A10-5700/5800x and older) but not the newer GCN models like the entire 7xxx series.

You HAVE to use amdgpu (or amdgpu-pro) on them, but the support and tools for that driver set are still VERY limited and primitive.