Brightness button jammed

[ping_uin]

Hello,

a few days ago, I've installed a debian testing system on my old netbook.
But there is a problem with the brigthness control. The brightness gets down-regulated permanently. If I raise it with FN+F5 (or in the options menu), I'm "fighting" against an automatic down-regulation. And after releasing the button everything is dark again after one second.
And the desktop notification of the brightness control is permanently shown.

It seems, that the darker-button is always pressed.

The system is a lot slower than it should be. And it feels like the graphical interface is a bit blocked somehow.

It isn't a mechanical problem, because while booting and in my windows 7 dual boot system everything works fine.
The problem starts in GDM and continues to the DE (I've tested Gnome3 and Xfce with the same result)

In the virtual console gets "^@" repeated to infinity as you can see on the photo. As a consequence, I cannot login from there because my username is always wrong..



Has someone an idea what could be the problem and how to solve it.

regards

Edit:

log for 1 button press of brightness down and 1 button press for brightness up.

Code: Select all

$ [23:01:52] simon@mamba :/sys/class/backlight/acpi_video0
> sudo acpi_listen 
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessup BRTUP 00000086 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
video/brightnessdown BRTDN 00000087 00000000 K
[...]

[emariz]

Those symbols are the output of pressing a non-mapped key in the command line. In my case, it is the output of Fn+F1.
I think that the brightness key spring is not being released and that is why the brightness always dims and that output is generated. Could you remove the key, clean it and check if the problem persists?

About the system feeling slow, it might be a video driver issue. What is your video device and what drivers are in use? What kernel?

[ping_uin]

I think that the brightness key spring is not being released and that is why the brightness always dims and that output is generated. Could you remove the key, clean it and check if the problem persists?

I think I can rule out a mechanical problem with the keyboard, because I have no problems in my windows 7 installation on the same netbook (from where I'm typing this).

About the system feeling slow, it might be a video driver issue. What is your video device and what drivers are in use? What kernel?

Might be, but it's a secondary problem for me. And maybe slow was the wrong word. The main thing is, that the UI is kind of blocked. I click and several seconds later (if ever) the UI reacts. But during the "wait time" i am able to type in the terminal.

regards