Brightness not changing when buttons pressed.

[mybellyisempty]

My T61p seems to have a quirk at the moment.

When I try to adjust the brightness, on battery power or AC, it doesn't change the brightness.

I've installed the newest System Interface Driver and the latest Hotkey driver...but nothing.

Any thoughts?

[yak]

I don't know if it's the same issue but something similar sometimes happen on my T60 running Vista. The OSD appears correctly but the brightness remains the same. Sometimes it helps to unplug and replug the laptop, other times I need to reboot. Happens twice a month maybe. I learned to live with it.

[GomJabbar]

Do you have the ACPI Power Management driver installed?

[mybellyisempty]

Yep. Every other control works (and the brightness works outside of Windows)...which seems strange: if it were a software problem, my reinstalling the Lenovo software should have fixed that.

[GomJabbar]

I don't know. Just make sure you are using the correct drivers for Vista. The ACPI Power Management driver is version 1.52. Power Manager is version 2.43. I believe you need both.

You can get everything here: http://www-307.ibm.com/pc/support/site. ... MIGR-67853

Look in Device Manager for clues. Choose View > Show Hidden Devices. Search for any anomalies. You can also look in Administrative Tools > Services, and search for services that are set to start automatically, but are stopped. I am not sure, but you may have something in C:\WINDOWS\Debug\UserMode\userenv.log (I am posting from XP, I suppose Vista has the same file).

[mybellyisempty]

Yeah, everything's there...if it were something simple and obvious I'd have fixed it by now...

[mybellyisempty]

Problem solved.

Today, while reformatting my laptop to install Vista w/ SP2 integrated, I had the problem pop up again.

I reformatted, and installed things 1 by 1, and found out it was a problem with the video driver. As I'm not gaming, I went back from the 185s to the 176.93 put on Lenovo's site, and the problem went away. I can't remember the last version that worked, as I seldom mess with my brightness controls, as I'm typically going from one AC outlet to another...but at least I figured it out.