How to stop Ubuntu from shutting down my screen when I close the lid

Question

I have a laptop linked to a huge TV that I use as main screen, but if I close the laptop's lid Ubuntu (16.04) decides it's time to turn the screen black, shut down the volume, and I can't do anything but opening the lid again, pressing some buttons, reinsert the password. I hate that. How can I tell Ubuntu to stop?

I've already tried two solutions:

1. Tried looking the solution on the best answer here, but I can't seem to find the file, so it's pretty much impossible to do anything;
2. Tried looking on the first alternative in the comments of the best answer (yeah, still the hyperlink above), but again, didn't find any file there, nor the directory;
3. Went for the alternative, still on the comments of the best solution, which I will put here:
   $ sudo apt-get install dconf-tools, opened dconf Editor application, went to org => gnome => setting-deamon => plugins => power. Here I made some changes.

lid-close-ac-action was set to 'ignore'

lid-close-battery-action was set to 'ignore'

lid-close-suspend-with-external-monitor was left unchecked

Then I rebooted the service with $ sudo service systemd-logind restart, but if I close the lid the whole screen turns off, so nothing changed! I've even tried rebooting the pc for the sake of trying even if I've restarted the service, but nothing changed...

What can I try?

Answer 1

You can easily disable this by clicking the System Settings icon in the Launcher/Task bar, and then clicking on Brightness & Lock.

From there, you flip the Lock switch to the off position, and un-check the "Require my password when wakening from suspend." check-box.

The other thing you have to watch for is whether or not your system has a large enough swap partition to actually go into suspend, if the system is set up to go into suspend, when the lid is closed. Your swap partition needs to be at least the size of your RAM, preferably a few Gig larger. If your swap partition isn't large enough, your system will hang when it tries to suspend.

If you aren't set up to Suspend properly, then you will also need to go over your Power settings, so they don't shut down the system when the lid is close. You can do this in System Setting -> Power.