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!!! :)