Can't get laptop display to turn off when connected to external display

Greetings all,

Running 15.10 (patched).

I have a lovely Dell Precision laptop hooked up to a lovely Dell external monitor via DP. Under display prefs I’ve tried several times to disable the laptop display, however every time I enter ‘Apply’ the external monitor (set to default display) goes to sleep. The laptop proceeds to follow suit and suspends.

I have no need for the laptop display to be on; in fact I would prefer to close the lid. Any suggestions?


Greetings. There should be options in the Power Management (System -> Administration -> Hardware) for choosing the close lid and sleeping behaviour. I’m not sure why the system would suspend/sleep when the display is off. :confused:

On most laptops with external monitors; there are FN button combo’s to switch off the laptop monitor!. :smiley:

Thanks lah7. I even loaded 16.04 to see if that would correct the problem - no luck. Oh well.

I’m running Synergy across four machines so it’s more irritating. I’ll figure something out.

Heya @wolfman. I should have mentioned I tried that initially.

I need to check if there is a BIOS update for this machine; that might sort it out. :wink:

1 Like

Hi ErsatzGood,

If this is an Optimus laptop, which GPU driver are you using, if still nouveau, consider trying the propriety NVIDIA driver?

For example, I’ve found an older Optimus laptop I’m using works best while directly using either iGPU (Intel selected in NVIDIA settings, reboot NVIDIA GPU shuts down), or dGPU (NVIDIA GPU selected in BIOS), but not so well while trying to use iGPU with NVIDIA selected in NVIDIA settings with a connected screen.