# LCD backlight always on

## Klonk

Hi,

I have a Gericom Supersonic Laptop which is really nice.

Now i have the following problem:

APM is actived in the Kernel and Screen Blanking is also activated.

After some time the screen gets black, but the backlight is not disabled. Both for the console and X.

The supported APM version is 1.2. Battery status is shown correct so APM is working.

I tried to use DPMS with X but this does not help.

I have not emerged apmd yet. Do I have to to get this working?

Any ideas?

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## kitano

have you tried 

```
xset dpms force off
```

what does it do (keep your hands away from your mouse while doing so)?

kitano

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## Klonk

That's the Problem: nothing happens! no flashing of the screen, nothing.

But also no error message.

My Laptop uses a Trident Cyberblade i1 chip and this chip should support DPMS. Hmm..

Does DPMS only work with APM or ACPI?

Maybe I made somthing wrong during testing (maybe APM and ACPI both activated in kernel) maybe this confused DPMS.  

But I think DPMS should not be bothered from APM or ACPI or am I totally wrong?

I activated DPMS through xset +dpms and also set it in XF86Config. Nothing worked.

I'll double check this at home and try it with only ACPI activated and then with only APM activated. 

I didn't  find any option though for disabling the backlight with APM or ACPI. I only found the comment about the option in the kernel that "disables the backlight for some laptops", but not mine.

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## Klonk

OK I tried DPMS with only ACPI enabled.

All Options of DPMS resulted in a blank screen. But the backlight is still on. 

Any more ideas? Maybe some special program? 

It is possible to switch it off (as Windows can do it) but how?

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## kitano

I'm using dpms with apm on a dell inspiron 4000 w rage mobility chipset. it works pretty well.

but i can't tell you if its for apm, cause the bios of this machine has a _buggy_ acpi, and that never really worked. i tried it though, but too many things couldn't get run. so i stayed with apm...

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## Klonk

I tried also with APM only and the effect is the same. But I had other problems with APM when closing the lid.

It looks almost like I have to live with the enabled backlight.

Maybe it's a special ACPI mode I have to use.  I don't know. I have to check all information about ACPI I could find.

If I come to a conclusion I'll post it here.

But still suggestions are welcome.

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## RemcoNL

I have the same CyberBlade i1, and the only thing that turns off the backlight, is closing the cover from the console (NOT from within X)...

If you've found an easier way, please post it  :Smile: 

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## Klonk

I haven't found any solution for that at the moment.

I just found using ACPI gives more features therefore I'm not using APM. 

I hope it will work with the new kernelversion (2.6) as there are some improvements with ACPI I heard (or read somewhere)

I think blanking the display is controlled by the kernel (not X).

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## angelacb

Did anyone ever got it working with ACPI + Turning off backlight?

I've tried it with just APM support and in X windows it works perfectly, however in terminal console, if i use setterm -blank 1 the screen to make it blank then i get a weird problem. The LCD will be off in powersaving mode, however, when i try to resume the terminal screen messes up. The bottom part of the screen appears at the top and the top part of the screen appears at the bottom. (This is like the full screen SPLIT in half where the bottom part is at the top and top at the bottom.) I use the kernel's blanking feature to turn off the monitor in the Advanced Power Management section to make the backlight turns off as well. This problem also occures if i'm in terminal and press Fn + D (turns off the LCD - Dell inspiron 8100 fn keys)

Just wondering if anyone successfully have ACPI working with these Dell i8k series laptops to turn off the backlight as well in both X windows and in virtual terminal. My X is working fine with DPMS but setterm doesn't give me any options for ACPI to change the mode in terminal where the backlights goes off as well.

Best Regards,

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## Wedge

Ive been fighting this same problem for a while but today i desided to take it upon myself to fix it (im really bored at work) 

I was going though all the posts on this problem trying everything everyon suggested.  Nothing worked.  Out of pure shits and giggles I desided to emerge xorg-x11 and see what would happen.

After a few hrs of compiling and then another 30 mins or so of play'n with the config so it was similar to my old one w/ some extra font changes that was in the wiki for xorg  http://gentoo-wiki.com/HOWTO_Xorg_and_Fonts

X started up just fine after I fixed all the config issues.  So I rebooted just to make sure.  KDM started up just fine, I logged in and then proceeded to test the blanking.   I just set the power management to 1 min and watched in anticipation (its true a watched monitor never goes into suspend mode  :Wink:   ) to my surpise bam.. backlight went out.. i was soo happy i could have jumped for joy and ran around the office singing, however I didn't.  Its not like im suppose to be doing this or anything  :Wink:  want to avoid unessiary questions.   

So those who wanna try this here was the steps w/o all the babble I was carring on about.  

```
#emerge unmerge xfree
```

```
#emerge xorg-x11
```

```
#xorgconfig
```

The rest im sure you can figure out if you got xfree installed and working before.. 

Hope this works for any of you, i know it did for me

IBM ThinkPad x31

512MB DDR 

40GB Hard Drive

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## psycovic

I've also got this problem, and when I do 

```
xset dpms force off
```

it tells me "unable to open display "" "  (all quotes nested correctly).  Any ideas?

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## jewps

If you've got a radeon, try radeon tools, i heard it works but I don't need it for my laptops, one is a M9 and the other is a mach64/rage mobility..

also, did you put in any dpms options? such as standby, turn off, etc.. ?

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## oumpah-pah

 *psycovic wrote:*   

> I've also got this problem, and when I do 
> 
> ```
> xset dpms force off
> ```
> ...

 

Maybe you should try to specify the display explicitly:

```
xset -display :0.0 dpms force off
```

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