Vaio Z11 - Brightness control stops responding

I am having a problem with my Vaio Z with a fresh install, relating to the automatic keyboard backlight and display backlight adjustment, and manual control of the display backlight adjustment with the Fn keys.

So from a fresh boot or reboot, automatic brightness control of both devices seems to work fine. The Fn key combos will also work correctly to control display backlight. And then seemingly at random, ambient light sensor control will freeze, and the function keys will no longer manually adjust brightness. It seems to happen regardless of which graphics setting I'm using, and it also happens even with both ambient light sensor functions turned off.

I've got all of the latest drivers and software from Sony's website installed (sans non-essentials,) so I'm not sure what could be going wrong. Both the power management and event services are running. Has anyone else had this issue, and perhaps had better luck in solving it?

 

Interesting.

I get the same problem if I run any application that queries the hardware - e.g. Everest, SiSoft Sandra and even CPU-z...

As soon as I run them, the brightness adjustment just stops working...

Looks like another weird bug of system firmware of new Z.

 

Ohh, that could be it: my obsessive curiosity with how hot the computer is running. I'll have to give not running hwmonitor every ten minutes or so a try. Thanks for the tip.

 

I've found if I flip the speed/stamina once or twice, it resets something and I get control of the brightness back. That, or hit power to make the computer to sleep and then wake it back up.

 

Not sure about the Z series, but on the FZ series sometimes the onscreen brightness or volume controls stop responding (rarer under Win7 than it was with Vista BTW) and just logging off and back on would restore it. Not a reboot, just a simple log off.

Gary

 

I have the same issue, sometimes it seems like the brightness goes down on it's own and the FN keys don't bring up the brightness level unless i switch the speed/stamina switch (no, it's not set to auto)

 

I have this exact problem, I posted about it in the owners thread and another guy also had the same issue.

 

I also have the same problem and reported in older thread but it got interest from no one.

Now i still don't know why but it occurs in every installation method, factory default, clean install with US drivers, Asia drivers.

PS.
Running CPU-Z, HWMonitor also cause this problem.
Logoff/Login method did not resolve this problem.
Sleep/Wakeup can resolve this problem

 

Seem this problem does interest no one.

I found that if this problem occur you'll shutdown very slow (screen dark but power button doesn't go off yet)

 

I had this problem, you have to turn off the automatic brightness in Vaio control center.

Once you do that you are all good.

 

I try disable automatic brightness and then run cpu-z the problem still remain. I can't adjust brightness anymore

UPDATE: Finally psyq321 found that problem cause from ACPI tables do get corrupted when you run system software like CPU-Z. It likely to occurs only in QuadSSD Model. You can see at #58 http://forum.notebookreview.com/showthread.php?t=476311&page=6

 

I have this problem too.

 

I read through that a bit. Does anyone know if this occurs with a triple raid set up? I have the 192GB SSD (64GB x 3)...

 

Now that I have my Z, I can confirm: This DOES occur with triple RAID set up.

Anytime I run HWMonitor, I lose the ability to adjust the brightness, and my power plans don't modify the brightness accordingly when I unplug and go to battery. The HWMonitor also seems to create problems with the hybrid graphics system. When HWMonitor is active, switching between Speed and Stamina doesn't immediatey do anything. Sometimes I'll switch from Stamina to Speed and the blue "Auto" light lights up. A long time after I make the switch (a few minutes or so), I'll get the little popup asking me if I want to confirm the graphics switch.

Very annoying.

 

I just got this problem. Weird.

Change the mode to stamina and got it back to work. Very odd!

 

Same thing happens on my Z after running hwmonitor and/or cpuz - no brightness control, no audio control, even loses keyboard backlight, even the speed/stamina switch stops responding. First time I got it back putting the computer in and out of sleep. Ran cpuz again out of sleep, OS totally hung up trying to enter sleep. Had to hard power off.

This is my own OS installation, not the stock OS that came with my Z which was also happening.

 

I own a Z12L9E with a 500 GB Toshiba HDD (instead of SSD) : no problem.
Brigthtness is working while and after HWmonitor or CPUZ run.

In my opinion, this issue deals with RAID only