Linux Mint Forums

Hello, I run Mint 14 Nadia and I have a serious problem with the screen brightness.
I can't adjust it from ''brightness and Lock'' or the Fn keys..

I have tried using:
xbacklight -set 50
Changing line 11 and 12 in GRUB file (/etc/default/grub).
changing manually (sudo echo 5 > /sys/class/backlight/acpi_video0/brightness).
and (sudo setpci -s 01:00.0 F4.B=50).

Nothing has worked. I would appreciate any guidance. Thanks.

System info:
System: Host: nikos-Aspire-5745DG Kernel: 3.5.0-17-generic x86_64 (64 bit, gcc: 4.7.2)
Desktop: Gnome Distro: Linux Mint 14 Nadia
Machine: System: Acer product: Aspire 5745DG version: V1.01
Mobo: Acer model: ZR7D Bios: INSYDE version: V1.01 date: 08/10/2010
CPU: Dual core Intel Core i3 CPU M 370 (-HT-MCP-) cache: 3072 KB flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 9576.92
Clock Speeds: 1: 933.00 MHz 2: 933.00 MHz 3: 933.00 MHz 4: 933.00 MHz
Graphics: Card: NVIDIA GF108 [GeForce GT 425M] bus-ID: 01:00.0
X.Org: 1.13.0 drivers: (unloaded: fbdev,vesa) FAILED: nouveau Resolution: 1366x768@120.0hz
GLX Renderer: Gallium 0.4 on NVC1 GLX Version: 3.0 Mesa 9.0.3 Direct Rendering: Yes
Audio: Card-1: Intel 5 Series/3400 Series Chipset High Definition Audio driver: snd_hda_intel bus-ID: 00:1b.0
Card-2: NVIDIA GF108 High Definition Audio Controller driver: snd_hda_intel bus-ID: 01:00.1
Sound: Advanced Linux Sound Architecture ver: 1.0.25
Network: Card-1: Atheros AR9287 Wireless Network Adapter (PCI-Express) driver: ath9k bus-ID: 03:00.0
IF: wlan0 state: up mac: <filter>
Card-2: Atheros AR8151 v1.0 Gigabit Ethernet driver: atl1c ver: 1.0.1.0-NAPI port: 2000 bus-ID: 02:00.0
IF: eth0 state: down mac: <filter>
Drives: HDD Total Size: 500.1GB (23.3% used) 1: id: /dev/sda model: WDC_WD5000BEVT size: 500.1GB
Partition: ID: / size: 455G used: 109G (26%) fs: ext4 ID: swap-1 size: 4.15GB used: 0.00GB (0%) fs: swap
RAID: No RAID devices detected - /proc/mdstat and md_mod kernel raid module present
Sensors: System Temperatures: cpu: 48.0C mobo: N/A gpu: 45.0
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 154 Uptime: 2:14 Memory: 709.4/3819.3MB Runlevel: 2 Gcc sys: 4.7.2 Client: Shell inxi: 1.8.4

Try this:

Intructions:

1. Open up your terminal

2. Copy and paste the following code into the terminal, and press enter:

sudo sed "s/\(GRUB_CMDLINE_LINUX=\)\"\"/\1\"acpi_­osi=Linux acpi_backlight=vendor\"/" /etc/default/grub -i

3. Enter your password when prompted and press enter again.

4. Now copy and paste the following code into the terminal, and press enter again:

sudo update-grub

5. You're done. Now close the terminal, and re-boot your computer.

Courtesy of Carl Duff

marcove wrote:Try this:

Intructions:

1. Open up your terminal

2. Copy and paste the following code into the terminal, and press enter:

sudo sed "s/\(GRUB_CMDLINE_LINUX=\)\"\"/\1\"acpi_­osi=Linux acpi_backlight=vendor\"/" /etc/default/grub -i

3. Enter your password when prompted and press enter again.

4. Now copy and paste the following code into the terminal, and press enter again:

sudo update-grub

5. You're done. Now close the terminal, and re-boot your computer.

Courtesy of Carl Duff

Thank you for the help but nothing has changed...
I still can't change the brightness..

DId you change your previous try back to the default config first??

If not, there may be a conflict.

I have used Carl's code on several Acer's without a problem. In fact, I'm typing this on an Acer AO-756/Mint 14.1 Cinnamon.

Try installing the "indicator-brightness" program.
In the Terminal type each command and press Enter:

sudo add-apt-repository ppa:indicator-brightness/ppa
sudo apt-get update
sudo apt-get install indicator-brightness

If that doesn't work then open Nemo and go to /etc/default. Right click on the grub file and select "Open as Root". Open the file and change the line
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to one of the following lines, starting with the top one:

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=Linux”
GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi="
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quite splash acpi_osi=Linux acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash nomodeset acpi_backlight=vendor”

Save the file, open the Terminal and type
sudo update-grub
Reboot and test your laptop.
You will have to repeat the process for all 4 lines.
If the problem persists try changing the line:
GRUB_CMDLINE_LINUX=""

to one of the following lines, just like you did above:

GRUB_CMDLINE_LINUX="acpi_osi=Linux"
GRUB_CMDLINE_LINUX="acpi_osi=Linux acpi_backlight=legacy”
GRUB_CMDLINE_LINUX="acpi_osi=Linux acpi_backlight=vendor"