I have a pendrive with Linux Mint 13 DVD 32 bit installed on it (with persistence working!), and running it on my Acer Aspire 5750 notebook (Core i3 2310M with Intel HD Graphics 3000).
My problem is that the "Fn + arrows" combo for changing screen brightness is not working. When I try to use the combo, the system actually shows the icon on my screen, but the brightness doesn't change at all.
I followed the instructions on this topic: http://forums.linuxmint.com/viewtopic.php?f=42&t=45271
(trying the first method), so these are the steps I made:
1 - I opened terminal and typed: gksudo gedit /etc/default/grub
2 - In the text that opens, I found the line which says GRUB_CMDLINE_LINUX="" and inbetween the "", I inserted the words "acpi_backlight=vendor", and saved the file.
3 - Again in terminal, I typed: sudo update-grub
Unfortunately, in this last step, the terminal showed the following message:
/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).
Please, what do I need to do, or what am I doing wrong? (Sorry for my bad English)