Screen brightness switches from bright to moderate randomly. Ubuntu 7.10

[Finn]

My screen brightness goes from bright (seems like the brightest possible) to medium brightness, vice versa, randomly. Im actively using the laptop when this occurs, so there should be no idle-power-saving stuff interfering.

The floating window displaying current brightness _does not_ appear as it switches, as opposed to the other bug reports Ive seen regarding this.

I have a MacBook Pro Intel,

$ dpkg -l gnome-power-manager
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-==============-==============-============================================
ii gnome-power-ma 2.20.0-0ubuntu

Anything else I should provide? Ive not touched any default power management settings anywhere. My Ubuntu installation is practically fresh (except replaced with fglrx).

[Johan Gunnarsson (johang)]

I have the same problem on my Dell 640m running Ubuntu 7.10 final, "intel" xorg driver (Intel 945GM chip). If you need logs or anything, I'm happy to provide it.

[andbelo (andbelo)]

I have the same problem on a Dell Inspiron 6400 notebook (15,4", ATI x1300), but it behaves differently depending on use of AC power or battery:

1. On AC power: it turns 100% bright randomly. Manually setting it darker works for a few minutes, then it increases to 100% again.

2. On battery: The default if darker. Even adjusting to be very bright, it turns back to the previous value.

[Finn (johnsenf)]

This does not happen when Ive physically removed the battery and only using power cord. Don't know if this is useful or not, just an observation I made (as my battery just broke and I'm waiting to get a new one)

[Johan Gunnarsson (johang)]

It just reset my brightness to 50% (less than it was before), so this bug, at least for me, doesn't always reset to 100% when AC is used. I also would like to note that this didn't happen in Feisty.

[andbelo (andbelo)]

I found it to be related to gnome-power-manager in my case. It sets the brightness to the gnome-power-manager settings even with the "Dim display when idle" check-boxes unchecked. When I use hotkeys (Fn + Up/Down) to set the brightness, it only stays for a few minutes, then it returns to gnome-power-manager settings. Hotkeys doesn't set the gnome-power-manager brightness.

[impact (impact-atlas)]

If you right-click the gnome power manager icon and select the power history graph, does it show a lot of AC Adapter connects/disconnects (dark blue and medium blue circles) even though the AC Adapter is always plugged in? (Like in this bugreport: https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/147560 )

[andbelo (andbelo)]

No, it doesn't. I unplugged and plugged back the AC power and this was
the only time when I saw such dots in the power history graphs.

Regarding the annoyance itself, I disabled the function that
automatically adjusts the screen brightness in gnome-configurator
unchecking the option:

apps/gnome-power-manager/backlight/enable

Now the brightness stays on my settings.

impact wrote:
> If you right-click the gnome power manager icon and select the power
> history graph, does it show a lot of AC Adapter connects/disconnects
> (dark blue and medium blue circles) even though the AC Adapter is always
> plugged in? (Like in this bugreport:
> https://bugs.launchpad.net/ubuntu/+source/linux-
> source-2.6.22/+bug/147560 )
>