Greetings.
I use GeForce 7600 GS with dual LG L1900 LCD monitors.
OS is Linux Slackware 2.4.31 kernel.
Graphics driver: NVIDIA-Linux-x86-1.0-9755-pkg1
One monitor on DVI output; one on VGA output.

Problem:
Backlight stays on when in standby/screensave mode.

These produce blank screen, but not powerdown:

xset dpms force off
setterm -powerdown 1

Here is the entry in /etc/xorg.conf

Section "ServerLayout"
Identifier "Multihead layout"
Screen 0 "Screen0"
Screen 1 "Screen1" LeftOf "Screen0"

Option "BlankTime" "1" # Blank the screen in 10 minutes
Option "StandbyTime" "2" # Turn off screen in 20 minutes
Option "SuspendTime" "3" # Full hibernation in 30 minutes
Option "OffTime" "4" # Turn off DPMS monitor

InputDevice "Mouse1" "CorePointer"
InputDevice "Keyboard1" "CoreKeyboard"
EndSection


The screen goes black. but I can see from the faint glow that the backlight is still on.
Is this a problem? apart from energy usage which is negligible anyway, I feel that killing the backlight is desirable to save wear on the light source and LCD cells.

Is there some way I can configure my setup to kill the backlight in standby?
Help much appreciated.

More info - addebdum to my own post.

Here is a command and response which might provide useful clues.

~# setterm -powersave on
cannot (un)set powersave mode

What does that mean?

JC