Comment 12 for bug 872652

This method appears to reliably re-enable my backlight when it gets stuck off. @Joshua, please try each of these sequences (without disabling dpms) and describe your results if they differ from mine.

"Log in in the dark and tap brightness-up"

1. log in to the graphical session, and let it time out and switch off the backlight (so that its in the stuck dark state).
2. carefully type your password "in the dark" and hit Enter -- backlight is *still* off, but you should actually be back in your graphical session now.
3. tap your brightness-up keyboard key several times -- my screen backlight lights up at this point.

"Lid close on a different VTTY"

1. log in to the graphical session, and let it time out and switch off the backlight (so that its in the stuck dark state).
2. switch to a different virtual TTY with e.g. Ctrl-Alt-F1 (some systems like my Studio 15580 need Fn-Ctrl-Alt-F1).
3. close the lid (note, because you're not on the graphical TTY, the system does *not* suspend due to closing the lid).
4. open the lid -- my backlight comes back on at this point.
5. switch back to the graphical session with Ctrl-Alt-F7 (you should be at the "unlock" screensaver dialog).