Comment 6 for bug 872652

@Joshua-

> * How can I manually induce a display suspend?

$ sudo /usr/sbin/pm-suspend

> * How do I manually change the display brightness level?

You should be able to run this sequence from a terminal window on your external monitor (or while logged in to the laptop from another machine) -- it will reflect and affect the laptop display brightness. When the laptop screen is stuck in its dark state after resume, does the 'brightness' value below display as zero? Does that value seem to change when you press the brightness up/down keys?:

$ cd /sys/class/backlight/intel_backlight
$ cat max_brightness
{note the max brightness value (it won't ever change)}
$ cat brightness
{note the current brightness value; it *should* reflect the laptop screen backlight brightness, from 0 (off) to the max value}

You can change the brightness value manually as follows. Does changing it actually affect the screen brightness (once you're in the stuck dark state) or not?

$ cd /sys/class/backlight/intel_backlight
$ echo {somevalue} | sudo tee brightness
Replace "{somevalue}" with the max brightness value.