Hi all,
I am using Ubuntu 10.04 LTS in Samsung N148. I can't see any option to adjust brightness in System->Preference->monitor. Is there any shell command to adjust brightness ? I have used xgamma -gamma but it change the gamx not brightness.
Cheers
It *might* be different in your system, but this works just fine in mine.
echo "80" > /proc/acpi/video/VGA/lcd/brightness
Change "80" to some reasonable number.
But I don't have video folder under /proc/acpi/ 
these are the folder i have
ac_adapter/ event processor/
battery/ fadt sleep
button/ fan/ thermal_zone/
dsdt info wakeup
What would be the solution then??
I'm assuming you've got a laptop since the question wouldn't make much sense otherwise, though you didn't say.
Try 'modprobe video'. If you still don't have it, blame the folks that wrote your standards-incompliant proprietary windows-only BIOS.
Doesn't your laptop have special keys to adjust the monitor brightness? What do those do?
What is this 'modprobe video' and of course keys are not working. I have smartdimmer installed but i am getting an error init_nvclock() failed!.
lsmode command also gives me video in that so that means to me that I have video.ko installed. But I don't know why proc/acpi don't have video folder
I m nt a expert in ubuntu, pls help me
Geo
It's a command that you run in the shell as root. It should load the 'video' module if it isn't loaded already, which may give you ACPI control of your laptop monitor.
Because, as already said, your laptop may have a proprietary BIOS which controls video in a non-ACPI way, hence only works in windows and even then probably only with special drivers. What is your laptop?
Hi sorry for the late reply. I tried modprobe -c which gave me many video named modules. Could you please tell me the extract command which i have to run?
its SAMSUNG N148 ( same as N150 but comes without any OS)
Thank you for your cooperation Corona688. I hope you may have some solution which solve my problem.
Exactly what I said, no more, no less: "modprobe video". 
But that's not the solution. Now that you've given me the model number, google got it. They had to add kernel patches to let fn-keys work on quite a lot of Samsung models, yours included.