Ubuntu – Ubuntu 16.04 only works when secondary monitor is connected

driversgraphicsmultiple-monitorsnvidiavga

I have Ubuntu 16.04 on a Gigabyte Aero 14 laptop having Geforce GTX 1060 VGA. Using different nvidia drivers results in different behavior. For example, "nvidia-384" and "nvidia-387" don't detect the second monitor.

Currently, I have installed nvidia-390 (tried both .run file from nvidia website, and the package from ppa:graphics-drivers/ppa). It works when the external monitor is attached, but when I disconnect the monitor and reboot, ubuntu crashes after login.

Some notes:

  • I have already tried Ubuntu 16.04 + Nvidia Driver = Blank screen
  • Reinstalled drivers
  • Tried both UEFI disabled and enabled
  • Tried Unity and Gnome
  • Nouveau driver, nvidia-367, nvidia-384, and nvidia-387 don't detect my second monitor
  • Tried both mini-display to VGA port, and HDMI to HDMI
  • sudo lshw -c video result: https://pastebin.com/raw/pZmkDbWC
  • CPU Info: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
  • BIOS info: enter image description here
  • In BIOS, the only option related to VGA I see is 3D Graphic Acceleration
    enter image description here

Best Answer

You appear to have an Intel "Skylake" CPU in your Gigabyte Aero 14 laptop. The Skylake has integrated Intel graphics and unless I'm mistaken is used by default to drive the primary (non-external) monitor. Issues have been reported with screens freezing related to the Skylake line of mobile processors. Considering everything you've already tried and the results you've reported I think it's safe to say that this may be a kernel issue and not the usual graphics driver issue. Make sure you do not have nomodeset or vga= as a kernel parameter, since Intel requires kernel mode-setting.

It could also be useful to temporarily try intel_idle.max_cstate=1 as a kernel boot parameter.

You might also reconfigure X.

EDIT: Since your laptop has Optimus Graphics technology you might need to install nvidia-prime or bumblebee and check your BIOS display setting to obtain the desired results (as it's unclear at least to me whether you've selected a specific display adapter or are using a hybrid graphics setting .

You might also obtain some clues from this question.

It's also possible that in your numerous attempts to find the right graphics driver for your situation that you may have inadvertently created something of a mess in which case you might find this answer particularly useful.

Related Question