Unable to change brightness in a Lenovo z500 laptop with Ubuntu 15.10

Question

Brightness adjustment keys have no effect (although they are recognized by the environment), and I can't change the brightness using GUI tools as well. In Windows 10 i had the same problem and after i changed my driver into those for windows 8 i could fix it.

Output of "sudo lshw -C video":

*-display               
       description: 3D controller
       product: GK208M [GeForce GT 740M]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: driver=nvidia latency=0
       resources: irq:32 memory:d2000000-d2ffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:3000(size=128)
  *-display
       description: VGA compatible controller
       product: 3rd Gen Core processor Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 09
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:28 memory:d3000000-d33fffff memory:e0000000-efffffff ioport:4000(size=64)

I use the property driver of Nvidia instead of Noveaou

Output of "ls /sys/class/backlight/*/brightness":

/sys/class/backlight/intel_backlight/brightness

I've yet try to resolve the problem follow this:

Screen brightness isn't taking effect on a Lenovo Z570

but this haven't working for me.

How Can i fix it? Thank you!!! :)

Answer 1

I have exactly the same model of PC and the same problem as you. I don't know how to solve this problem but just boot into windows and change your brightness level as you want, you will see the difference next time when you boot into Ubuntu. but remember not to dim the screen otherwise you have you do this again...