For the longest time after about 5 minutes my screen would blank out. Now the screen will go blank after 5 minutes but then 2 seconds after that it will light up white and keep the laptop backlighting on. I didn't change any settings to my knowledge it just happened randomly after powering it on one day and has occurred since then.

I wish to resort back to blanking the screen out completely since I leave this computer on all the time and it's hard to sleep with a huge white light all the time.

xset dpms force off just yields me:

xset:  unable to open display ""

You need to tell xset which display to use:

export DISPLAY=:0
xset q
  • 3
    > export DISPLAY=:0 > xset q after that I have ' unable to open display ":0" ' – KeyTrap Jun 12 '15 at 12:58
  • Had same problem when was trying to access monitor remotely with user other than logged in. – Nikolay Ruban Dec 11 '15 at 11:51
  • 1
    Then I get xset: unable to open display ":0" – yode Jul 2 '17 at 3:57
  • export DISPLAY=0 instead. It should work – shuva Oct 28 '18 at 15:06
  • Neither of the methods works in systemd foked process. – Seff Aug 23 '20 at 19:09

Try vbetool instead xset:

sudo vbetool dpms off

It's works fine for me.

  • 1
    Sorry I got the error "Real mode call failed" – bitdancer Oct 27 '19 at 14:51

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