iMac 12,1 (mid 2011 21.5) 13.04 Brightness.

[sgarrand]

Hello All,

I've installed Ubuntu 13.04 as a dual boot with OSX and in Ubuntu on my mid 2011 21.5 iMac I cannot change the brightness. I've Googled until my head hurts but none of the solutions work for me. Any ideas? Thanks.

Scott

[Josh1]

Hello All,

I've installed Ubuntu 13.04 as a dual boot with OSX and in Ubuntu on my mid 2011 21.5 iMac I cannot change the brightness. I've Googled until my head hurts but none of the solutions work for me. Any ideas? Thanks.

Scott

Had same issue with 12.10, found that running the following fixed it:

xrandr --output LVDS --brightness 0.7

0.1 through to 1.0, find something you like.

[sgarrand]

warning: output LVDS not found; ignoring
xrandr: Need crtc to set gamma on.

The above is the output I received. It did not work. Googling "LVDS" tells me it's a laptop display, changing it to eDP worked.

xrandr --output eDP --brightness 0.7

Edit: Here's my XRANDR output. eDP is my iMac, DisplayPort-0 is my second monitor (brightness on that is fine).

scott@scott-iMac:~$ xrandr
Screen 0: minimum 320 x 200, current 3520 x 1080, maximum 16384 x 16384
eDP connected 1920x1080+0+0 (normal left inverted right x axis y axis) 475mm x 267mm
1920x1080 59.9*+
1680x1050 60.0
1400x1050 60.0
1280x1024 59.9
1440x900 59.9
1280x960 59.9
1280x854 59.9
1280x800 59.8
1280x720 59.9
1152x768 59.8
1024x768 59.9
960x540 59.8
800x600 59.9
848x480 59.7
720x480 59.7
640x480 59.4
DisplayPort-0 connected 1600x900+1920+180 (normal left inverted right x axis y axis) 442mm x 249mm
1600x900 60.0*+
1280x1024 60.0
1440x900 59.9
1024x768 60.0
800x600 60.3
640x480 60.0
720x400 70.1
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
DisplayPort-2 disconnected (normal left inverted right x axis y axis)
VGA-0 disconnected (normal left inverted right x axis y axis)

Scott

[sgarrand]

Had same issue with 12.10, found that running the following fixed it:

xrandr --output LVDS --brightness 0.7

0.1 through to 1.0, find something you like.

I wonder how to save this so it's persistent. It currently goes back to full brightness after a reboot. Also can't seem to get my magic trackpad connected again after getting lucky this morning.

Scott

[neorg]

This is how I solved the brightness problem on my iMac 27" 2011

http://www.robgroen.nl/content/imac-...setting-script

Simple adjust the brightness with a mouse click on a icon in your Gnome-Panel