Notebook monitor does not turn off when idle

Could you please send the output of gnome-power-bugreport.sh as detailed here:

https://wiki.ubuntu.com/DebuggingGNOMEPowerManager

I'm betting that GPM is not detecting that you have a LCD screen. This is done by looking at HAL and thusly would be a HAL bug if that is the case.

Thanks for reporting. Ted.

Ted, do you mean this "Laptop panel present: yes" ?

Distro version: DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=8.04
DISTRIB_CODENAME=hardy
DISTRIB_DESCRIPTION="Ubuntu hardy (development branch)"
Kernel version: 2.6.24-12-generic
g-p-m version: 2.22.0
HAL version: 0.5.10
System manufacturer: Hewlett-Packard
System version: F.09
System product: HP Compaq 6820s
AC adapter present: yes
Battery present: yes
Laptop panel present: yes
CPU scaling present: yes
Battery Information:
  battery.charge_level.current = 54054 (0xd326) (int)
  battery.charge_level.design = 54054 (0xd326) (int)
  battery.charge_level.last_full = 54054 (0xd326) (int)
  battery.charge_level.percentage = 100 (0x64) (int)
  battery.charge_level.rate = 0 (0x0) (int)
  battery.is_rechargeable = true (bool)
  battery.model = 'Primary' (string)
  battery.present = true (bool)
  battery.rechargeable.is_charging = false (bool)
  battery.rechargeable.is_discharging = false (bool)
  battery.reporting.current = 5012 (0x1394) (int)
  battery.reporting.design = 5005 (0x138d) (int)
  battery.reporting.last_full = 5005 (0x138d) (int)
  battery.reporting.rate = 0 (0x0) (int)
  battery.reporting.technology = 'Li-ion' (string)
  battery.reporting.unit = 'mAh' (string)
  battery.technology = 'lithium-ion' (string)
  battery.type = 'primary' (string)
  battery.vendor = 'Hewlett-Packard' (string)
  battery.voltage.current = 12505 (0x30d9) (int)
  battery.voltage.design = 10800 (0x2a30) (int)
  battery.voltage.unit = 'mV' (string)
GNOME Power Manager Process Information:
victor 5996 0.4 0.6 74420 12920 ? Ssl Mar19 0:01 gnome-power-manager
HAL Process Information:
110 5300 0.2 0.2 7432 5384 ? Ss Mar19 0:00 /usr/sbin/hald
root 5304 0.0 0.0 3344 1172 ? S Mar19 0:00 \_ hald-runner
root 5379 0.0 0.0 3408 1156 ? S Mar19 0:00 \_ hald-addon-input: Listening on /dev/input/event6 /dev/input/event1 /dev/input/event3 /dev/input/event4 /dev/input/event5
root 5387 0.0 0.0 3420 1204 ? S Mar19 0:00 \_ /usr/lib/hal/hald-addon-cpufreq
110 5388 0.0 0.0 2204 948 ? S Mar19 0:00 \_ hald-addon-acpi: listening on acpid socket /var/run/acpid.socket
root 5409 0.0 0.0 3408 1132 ? S Mar19 0:00 \_ hald-addon-storage: polling /dev/scd0 (every 2 sec)

I have exact the same problem.
Below is the output of gnome-power-bugreport.sh

Distro version: DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=8.04
DISTRIB_CODENAME=hardy
DISTRIB_DESCRIPTION="Ubuntu hardy (development branch)"
Kernel version: 2.6.24-15-generic
g-p-m version: 2.22.1
HAL version: 0.5.11rc2
System manufacturer: missing
System version: missing
System product: missing
AC adapter present: yes
Battery present: yes
Laptop panel present: yes
CPU scaling present: yes
Battery Information:
  battery.charge_level.current = 46420 (0xb554) (int)
  battery.charge_level.design = 86580 (0x15234) (int)
  battery.charge_level.last_full = 46420 (0xb554) (int)
  battery.charge_level.percentage = 100 (0x64) (int)
  battery.charge_level.rate = 11 (0xb) (int)
  battery.is_rechargeable = true (bool)
  battery.model = 'DELL YF0917' (string)
  battery.present = true (bool)
  battery.rechargeable.is_charging = false (bool)
  battery.rechargeable.is_discharging = false (bool)
  battery.reporting.current = 7800 (0x1e78) (int)
  battery.reporting.design = 7800 (0x1e78) (int)
  battery.reporting.last_full = 4182 (0x1056) (int)
  battery.reporting.rate = 1 (0x1) (int)
  battery.reporting.technology = 'Li-ion' (string)
  battery.reporting.unit = 'mAh' (string)
  battery.technology = 'lithium-ion' (string)
  battery.type = 'primary' (string)
  battery.vendor = 'SMP' (string)
  battery.voltage.current = 12753 (0x31d1) (int)
  battery.voltage.design = 11100 (0x2b5c) (int)
  battery.voltage.unit = 'mV' (string)
GNOME Power Manager Process Information:
yegle 2932 0.0 0.6 27168 7148 ? Ss Apr09 0:10 gnome-power-manager
HAL Process Information:
107 11262 0.0 0.2 6000 2348 ? Ss Apr09 0:23 /usr/sbin/hald
root 11263 0.0 0.1 3352 1072 ? S Apr09 0:03 \_ hald-runner
root 11276 0.0 0.1 5172 1852 ? S Apr09 0:00 \_ /usr/lib/hal/hald-addon-dell-backlight
root 11277 0.0 0.1 3416 1056 ? S Apr09 0:01 \_ hald-addon-input: Listening on /dev/input/event5 /dev/input/event7 /dev/input/event6 /dev/input/event1 /dev/input/event2 /dev/input/event3 /dev/input/event4
root 11292 0.0 0.1 3428 1196 ? S Apr09 0:00 \_ /usr/lib/hal/hald-addon-cpufreq
107 11293 0.0 0.0 2204 888 ? S Apr09 0:00 \_ hald-addon-acpi: listening on acpid socket /var/run/acpid.socket
root 11338 0.0 0.0 3420 1000 ? S Apr09 0:09 \_ hald-addon-storage: polling /dev/scd0 (every 2 sec)

I also have the same problem. It's a HP dv6500t CTO. (Nvidia 8400GS GFX Card)

michael@michael-ubuntu:~$ gnome-power-bugreport.sh
Distro version: DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=8.04
DISTRIB_CODENAME=hardy
DISTRIB_DESCRIPTION="Ubuntu 8.04"
Kernel version: 2.6.24-16-generic
g-p-m version: 2.22.1
HAL version: 0.5.11rc2
System manufacturer: missing
System version: missing
System product: missing
AC adapter present: yes
Battery present: yes
Laptop panel present: yes
CPU scaling present: yes
Battery Information:
  battery.charge_level.current = 52102 (0xcb86) (int)
  battery.charge_level.design = 74574 (0x1234e) (int)
  battery.charge_level.last_full = 52102 (0xcb86) (int)
  battery.charge_level.percentage = 100 (0x64) (int)
  battery.charge_level.rate = 0 (0x0) (int)
  battery.is_rechargeable = true (bool)
  battery.model = 'Primary' (string)
  battery.present = true (bool)
  battery.rechargeable.is_charging = false (bool)
  battery.rechargeable.is_discharging = false (bool)
  battery.reporting.current = 4192 (0x1060) (int)
  battery.reporting.design = 6000 (0x1770) (int)
  battery.reporting.last_full = 4192 (0x1060) (int)
  battery.reporting.rate = -1 (0xffffffff) (int)
  battery.reporting.technology = 'Li-ion' (string)
  battery.reporting.unit = 'mAh' (string)
  battery.technology = 'lithium-ion' (string)
  battery.type = 'primary' (string)
  battery.vendor = 'Hewlett-Packard' (string)
  battery.voltage.current = 12429 (0x308d) (int)
  battery.voltage.design = 14800 (0x39d0) (int)
  battery.voltage.unit = 'mV' (string)
GNOME Power Manager Process Information:
michael 6322 0.0 0.8 365492 18456 ? Ssl May22 0:22 gnome-power-manager
michael 6439 0.0 0.7 204700 16328 ? S May22 0:00 /usr/lib/gnome-power-manager/gnome-brightness-applet --oaf-activate-iid=OAFIID:GNOME_BrightnessApplet_Factory --oaf-ior-fd=53
HAL Process Information:
111 5461 0.0 0.2 40260 4268 ? Ss May22 1:14 /usr/sbin/hald
root 5526 0.0 0.0 22044 1256 ? S May22 0:17 \_ hald-runner
root 5541 0.0 0.0 24152 1220 ? S May22 0:01 \_ hald-addon-input: Listening on /dev/input/event6 /dev/input/event7 /dev/input/event1 /dev/input/event2 /dev/input/event3 /dev/input/event4 /dev/input/event5
root 5548 0.0 0.0 24164 1260 ? S May22 0:00 \_ /usr/lib/hal/hald-addon-cpufreq
111 5549 0.0 0.0 16668 964 ? S May22 0:00 \_ hald-addon-acpi: listening on acpid socket /var/run/acpid.socket
root 5574 0.0 0.0 24152 1180 ? S May22 0:19 \_ hald-addon-storage: polling /dev/scd0 (every 2 sec)
root 21166 0.0 0.0 24152 1272 ? S May23 0:01 \_ hald-addon-storage: polling /dev/sdc (every 2 sec)

I used to have this problem, but it is solved.

Check to that see that your screensaver is OFF. The screensaver, even if you tell it to display a "blank screen", will turn on the backlight. Silly, yes, but it is what it is. So if you have an LCD, turn the screensaver off.

In ubuntu:
system->preferences-> uncheck "activate screensaver when computer id idle"

Then, press "power management" on the bottom of the dialog. Here, check your setting for "Put display to sleep when inactive". This will turn off the backlight.

Your suggestion does not work. If I turn off the screen saver, then I go to power manager, and set monitor to sleep after 1 minute, I will just be looking at my desktop, and nothing will happen.

Strange is the fact that occasionally it works perfectly, and sometimes it fails completely.

Another thing to mention, is that I have an External Monitor connected, and the laptop lid is closed all the time.

I think the failure occurs when I connect the monitor, and set it to display to the external monitor, but when I close the lid, the external monitor shuts off. At this point, I move the mouse, the monitor comes back one, and never shuts off again.

"Strange is the fact that occasionally it works perfectly, and sometimes it fails completely."

As it turns out, Ubuntu has a strange way of defining idleness. Everyone else uses human input (mouse, keyboard, etc). Ubuntu is using cpu as well, and there is no way to unselect that part of it. So if your cpu is busy enough, you are not idle and the screen will not blank.

See here for more info, there is talk that it is fixed in Lucid.

https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/289322