Impossible to change screen brightness on iMac

Bug #176648 reported by Ludovico Fischer on 2007-12-16
This bug affects 5 people
Affects Status Importance Assigned to Milestone
hal (Ubuntu)

Bug Description

Binary package hint: hal

On a imac(white) Core2Duo, ATIX1600, there is no way, using tools included with the distribution, to change the intensity of the LCD backlight. One has to use a program by Nicolas Boichat called bl1.c (which by the way seems to have stopped working with the present state of 8.04-Hardy). This is annoying as the screen defaults to max brightness, which many find quite blinding. This problem seems to affect all models of Intel iMacs and Macbooks. I wonder if there is a solution at kernel level somewhere?

See also bug 457882, the same problem on a MacBook.

Steffen Röcker (sroecker) wrote :

Please check if this has been fixed in Hardy now.

Changed in hal:
status: New → In Progress
Changed in hal:
status: In Progress → Incomplete
Sebastian Urban (surban) wrote :

This has not been fixed in Hardy with latest updates.

Changed in hal:
status: Incomplete → New
Paolo Sammicheli (xdatap1) wrote :

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue for you. Can you try with the latest Ubuntu release? Thanks in advance.

Changed in hal (Ubuntu):
status: New → Incomplete
assignee: nobody → Paolo Sammicheli (xdatap1)
i72Envp#hac (i72envphac) wrote :

It is still an issue for me.

Ubuntu 9.10 64-bit version. iMac (Aluminum) model: MB325LL/A from early 2008.

summary: - Impossible to change screen brightness on iMac (white)
+ Impossible to change screen brightness on iMac
Paolo Sammicheli (xdatap1) wrote :

Thanks for your answer.

Changed in hal (Ubuntu):
status: Incomplete → Confirmed
assignee: Paolo Sammicheli (xdatap1) → nobody
description: updated
description: updated
Xhacker Liu (xhacker) wrote :

I am affected by this bug too. Please solve it!

James Cameron (quozl) wrote :

Also affected, on iMac11,1 27" i7 ATI M98L HD 4850 with Ubuntu 10.04 amd64. Have fglrx package installed. Backlight is turned off by DPMS idle timer fine. Backlight stays at a default brightness since boot despite DPMS activation. Backlight goes to maximum brightness on resume from suspend. Sunglasses or reboot are then required. xbacklight package ineffective. pommed package ineffective.

Xhacker Liu (xhacker) wrote :

This method can change the brightness.

Please fix the bug.

Forrest Sheng Bao (forrest.bao) wrote :

I wish this problem can be fixed soon. I hope to adjust screen brightness using my keyboard keys.

dino99 (9d9) wrote :
Changed in hal (Ubuntu):
status: Confirmed → Invalid
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