title: Ubuntu 16.04.3 intel skylake i915 external monitor not detected
body: <p>My external monitor, connected via HDMI was working fine but now is not being detected (it says 'No video input'). I'm pretty sure I didn't make any changes to make it stop - it was working on the same setup yesterday.</p>
  
  <p>I'm a pretty new linux user and also don't know much about graphics hardware and drivers. Appreciate any help, I'd like to understand what's going on!</p>
  
  <p>I'm running Ubuntu 16.04.3 kernel 4.10.0-33</p>
  
  <p><code>lshw -c video</code> gives:</p>
  
  <pre><code>*-display               
     description: VGA compatible controller
     product: Sky Lake Integrated Graphics
     vendor: Intel Corporation
     physical id: 2
     bus info: pci@0000:00:02.0
     version: 07
     width: 64 bits
     clock: 33MHz
     capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
     configuration: driver=i915 latency=0
     resources: irq:124 memory:f0000000-f0ffffff memory:e0000000-efffffff ioport:e000(size=64) memory:c0000-dffff
  </code></pre>
  
  <p>I've tried booting from grub into kernel 4.8.0 and the monitor still wasn't detected.</p>
  
  <p>I've also tried to no avail:</p>
  
  <pre><code>sudo apt-get update
  sudo apt-get install --reinstall xserver-xorg-video-intel xserver-xorg-core
  sudo dpkg-reconfigure xserver-xorg
  </code></pre>
  
  <p>I've also tried running the Intel graphics update tool and this also hasn't solved anything.</p>
  
  <p>EDIT: It seems like I get the 'No video input' probelm if I plug in the HDMI cord before the computer has finished booting.</p>