[SOLVED] Freeze Up / Crash-adjusting backlight brightness

[dblmint]

editig grub (as below) used to work in the past (and still works on my Kubuntu 12.04, and some other distros), but now 15 Olivia Mate (which I am trying to stay with as main disto), when grub mod, it renders function keys dead - cannot adjust at all

............................................................................

1] sudo nano /etc/default/grub

2] GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

3] sudo update-grub

4] reboot
..........................................................................

(see http://forums.linuxmint.com/viewtopic.php?f=49&t=114413 for background info...)

[roblm]

Are you having a problem with just the keyboard backlight and not the screen brightness?
Does your laptop freeze like you described in your other post from October of 2009 with Mint 15 if the line “acpi_backlight=vendor” is missing from the grub file?

You can try using these changes:
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=Linux”
GRUB_CMDLINE_LINUX_DEFAULT="quite splash acpi_osi=Linux acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi="
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi='!Windows 2012'”
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash noapic"
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi=force noapic nolapic"

Open the Terminal and type "sudo update-grub" and then reboot after each change.

Sometimes making changes to the grub file can cause startup problems. If this happens, then restart and select the correct operating system at the Grub Boot Menu and then press e. Go down to the line that starts with:
linux /boot/vmlinuz.......................ro quiet splash $vt_handoff

Remove the command you added, which will be between the word “splash” and “$vt”. Press F10. This change is just temporary and allows you to start your system. Then remove the command in the “/etc/default/grub” file.
If you have only one operating system installed, then a Grub Boot Menu may not be displayed. Hold down the Shift key while restarting, or if this doesn't work, keep tapping the Shift key.

I would also like some additional information.
Press Ctrl+Alt+F1 to enter the virtual console tty1. Type: /lib/udev/findkeyboards
Get the input/event number.

Type: sudo /lib/udev/keymap -i input/eventX
where X is the number you found in the previous step.

Press the two function key combinations that increase and decrease the keyboard backlight.
Press the Escape key.
You can't use the print screen function here, so use the command:
sudo screendump 1 > screenoutput.txt

Then type the command: sudo showkey -s
Again press the two function key combinations for the keyboard backlight.
Wait 10 seconds for the program to end. Then type:
sudo screendump 1 > screenoutput2.txt

Press Ctrl+Alt+F8 to exit the tty1 console. If this fails then try Ctrl+Alt+F7.
The files "screenoutput.txt" and “screenoutoput2.txt” will be found in your Home directory (/home/username). Post the results.

Finally, run these commands:
cat /sys/class/dmi/id/sys_vendor
cat /sys/class/dmi/id/product_name

[dblmint]

WOW! Now that was a reply!

Thanks for your expertise, I will have to try your Grub mods when I get a chance... THANKS VERY MUCH!