Comment 0 for bug 772050

I just updated to Ubuntu 11.04 Beta to find that the backlight of my monitor is off (or very low) and I can't turn it on.

The backlight intensity control never worked on any previous version of Ubuntu (the Fn key controls responded, and changed a bar on screen, but never really changed the backlight). The Fn key On/Off worked before. In the new kernel, the backlight is off (or very low) by default and the controls does not work, so I can't turn it on.

Now I am using the old 2.6.35-28-generic kernel to report this bug. I hope enough info on the system has been gathered. My laptop is an eMachines E725. lspci report the following about the video device:

00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
 Subsystem: Acer Incorporated [ALI] Device 0212
 Flags: bus master, fast devsel, latency 0, IRQ 44
 Memory at d0000000 (64-bit, non-prefetchable) [size=4M]
 Memory at c0000000 (64-bit, prefetchable) [size=256M]
 I/O ports at 50f0 [size=8]
 Expansion ROM at <unassigned> [disabled]
 Capabilities: <access denied>
 Kernel driver in use: i915
 Kernel modules: i915

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.42
ProcVersionSignature: Ubuntu 2.6.35-28.50-generic 2.6.35.11
Uname: Linux 2.6.35-28-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC272X Analog [ALC272X Analog]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC272X Analog [ALC272X Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: lucas 1822 F.... pulseaudio
 /dev/snd/pcmC0D0p: lucas 1822 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xd6700000 irq 45'
   Mixer name : 'Realtek ALC272X'
   Components : 'HDA:10ec0272,10250212,00100001'
   Controls : 15
   Simple ctrls : 9
Date: Wed Apr 27 18:33:25 2011
HibernationDevice: RESUME=UUID=3e3ff916-ea57-411c-81e3-43861b6b198d
MachineType: eMachines eMachines E725
ProcEnviron:
 LANGUAGE=pt_BR:en
 LANG=pt_BR.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: root=UUID=2cdcad63-4a14-4e12-9cd4-bf10a0d49acd ro locale=pt_BR quiet splash crashkernel=384M-2G:64M,2G-:128M
RelatedPackageVersions:
 linux-restricted-modules-2.6.35-28-generic N/A
 linux-backports-modules-2.6.35-28-generic N/A
 linux-firmware 1.52
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: Upgraded to natty on 2011-04-27 (0 days ago)
WpaSupplicantLog:

dmi.bios.date: 03/11/2009
dmi.bios.vendor: eMachines
dmi.bios.version: V1.03
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: eMachines E725
dmi.board.vendor: eMachines
dmi.board.version: V1.03
dmi.chassis.type: 1
dmi.chassis.vendor: eMachines
dmi.chassis.version: V1.03
dmi.modalias: dmi:bvneMachines:bvrV1.03:bd03/11/2009:svneMachines:pneMachinesE725:pvrV1.03:rvneMachines:rneMachinesE725:rvrV1.03:cvneMachines:ct1:cvrV1.03:
dmi.product.name: eMachines E725
dmi.product.version: V1.03
dmi.sys.vendor: eMachines