Screen Brightness does not change when power source changes

[daemones]

I've recently purchased a 2613-EAU T60, which is behaving perfectly except for one minor issue.

When I plug or un-plug the power cord, the brightness level of the LCD does not change as measured by the 0-7 levels adjustable by Fn-Home and Fn-End. The screen brightness does change sligtly, but not on the scale.

I'm using Power Manager version 1.13c, and havn't disabled any of the related services, to the best of my understanding.

If I use Fn-F3 to select a power profile, the brightness change will take affect when the new profile is selected.

Does anyone have any idea what I'm missing that makes this happen automatically?

[RonS]

There's a BIOS setting that controls whether the screen is bright or dim when running on battery. Hold down F1 when first booting up to get into the BIOS to change the setting.

[Kyocera]

There is also a setting in thinkpad configuration>Display>LCD to enable the brightness when running on battery to different levels.

[daemones]

I have both of these settings enabled; unfortunately the change in brightness does not get applied when I plug in / unplug the power cord. The brightness only changes if I open up the power management app and select a profile (even if I re-select the currently enabled profile).

[dawarner]

I thought I was having the same problem just now on my new T60. I say thought, because after two re installs of the power manager, I think I found out what is causing this behavior.

First off, this is not the "normal/high" BIOS dimming I am talking about. I have the AC brightness set at 7, and the battery at 0. The power manager was not changing the setting when plugging/unplugging the laptop.

What I finally realized is that if you leave the brightness alone, as set in the power manager, the switching works properly. If you change the display brightness using the Fn key, then plug/unplug the laptop, it will remain at the modified setting.

If you reselect the power scheme and leave it alone (don't change the brightness manually), it will continue to switch automatically.

Not sure if this is a bug or design, but it is annoying either way.

[dawarner]

Never mind, the behavior I previously posted has stopped and the Power Manager now refuses to change the brightness setting all together.

It appears at least a few of us are having this problem.

[GomJabbar]

What I finally realized is that if you leave the brightness alone, as set in the power manager, the switching works properly. If you change the display brightness using the Fn key, then plug/unplug the laptop, it will remain at the modified setting.

If you reselect the power scheme and leave it alone (don't change the brightness manually), it will continue to switch automatically.

Not sure if this is a bug or design, but it is annoying either way.

I believe this is normal behavior. When you change your display brightness manually with the Fn + Home/End keys, you are overiding the automatic setup. I suppose the code could have been written differently where the manual setting is overidden by the automatic setting when the power source changes, but this is not the case presently.

I never really thought about this much in using my ThinkPad. If I wanted a different brightness setting while on batteries, I would use the Fn + Home/End keys, or reset the power scheme from the battery icon in the Notification area. Doesn't seem like too big a deal to me, but then again we each are annoyed by different things.