Comment 50 for bug 41994

I can't believe this is another 5+ year old bug that is still unresolved. I am experiencing this issue on Ubuntu/Xubuntu 11.04. The problem is that somehow dpms calls are being made to turn the backlight back on when a mouse event occurs, even though the lid is still shut.

I ran into some difficulty because the Ubuntu acpi-support scripts don't run if they detect a desktop (gnome/kde/xfce/etc) power-manager app running. It's a pain to have to kill those, because I lose all GUI-based power management (battery indicator, etc.) on my laptop. However, I got so fed up with this issue that I felt it was worth it to block the power-manager app so that acpid could run the show.

In the end, the best solution I could find was to run lid.sh on a 1-minute recurring cron job. This forces the backlight off when the lid is closed and on when it's open. Not a very elegant solution, but at least I won't have to worry about burning out my laptop's monitor any more.

Also vbetool did not work for me. Specifically, it was able to turn off the backlight, but was not able to turn it back on. After using vbetool to turn off the backlight, I had to switch to a text console and back to get the backlight to come back on!