display does not turn off when screen closed

[Marty Jack]

(Sorry not in thread)

The event that happens when the lid closes and opens is reflected in /proc/acpi/button/lid/LID0/state.  This is normally watched (via the /dev/event* device) by a power manager.  Nothing in Xorg does anything with any of the switches (lid, power, sleep).

You will need to run some power manager such as the Gnome power manager or the Xfce power manager, where you should find it easy to configure what you want to have happen on a lid close.  I do not think anyone has created an LXDE specific power manager but you could raise this with the Lubuntu support channel to be sure.