I was on Ubuntu (vanilla, with Unity) 14.04 until yesterday, and since the new LTS version came out, I decided to go for an Ubuntu GNOME 16.04 clean install.
Since I installed Ubuntu GNOME 16.04 (64-bit), I have issues with the suspend mode (I did not have this problem on 14.04) on my Dell Inspiron 3537.
When I choose to suspend the session, the screen turns black, the fans go off for a few seconds (2 or 3 seconds), then they restart going faster and faster. I have to force shutdown (hold press power button) the computer to be able to restart it.
I did some research, and found out that Ubuntu 16.04 doesn't support the AMD Radeon proprietary graphic drivers. I don't know if it's related or not, but since I have an AD Radeon HD8850M, I ran an lspci | grep VGA
and here is the result:
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09)
03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Venus PRO [Radeon HD 8850M / R9 M265X] (rev ff)
Also, I have the open-source drivers installed:
$ sudo apt-get install xserver-xorg-video-ati
xserver-xorg-video-ati is already the newest version (1:7.7.0-1).
If you need any other information, please let met know.
sudo pm-suspend
and nothing happend.