External monitor works on Live ISO but not in installed OS


My laptop is a macbook pro 2011. This macbook has a dual GPU: a AMD Radeon HD 6750M and a Intel HD Graphics 3000.
I have downloaded the Opensuse 13.2 RC1 KDE live iso and created a usb pen drive to boot it.

When I first booted with the live usb I was amazed because everything worked out of the box. So, in a rush I installed it. lol!
After installation I booted the installed OS. This time the external monitor connected via display port didn’t work.
Under “Configure Desktop”->“Display and Monitor” I can see that the external monitor is detected and it’s set to the correct resolution.
Messing around with the monitor settings doesn’t do anything.

Booting again the OS from the live usb, the external monitor is working again.
Going to “Configure Desktop”->“Display and Monitor” shows that I have 3 connected monitors (I only have 2 :).
Here’s the output of xrandr:

xrandr -q
Screen 0: minimum 320 x 200, current 5520 x 1440, maximum 16384 x 16384
LVDS-1 connected 1680x1050+2560+195 (normal left inverted right x axis y axis) 331mm x 207mm
   1680x1050     59.88*+
   1400x1050     59.98  
   1280x1024     59.89  
   1440x900      59.89  
   1280x960      59.94  
   1280x854      59.89  
   1280x800      59.81  
   1280x720      59.86  
   1152x768      59.78  
   1024x768      59.92  
   800x600       59.86  
   848x480       59.66  
   720x480       59.71  
   640x480       59.38  
DisplayPort-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+
   1920x1200     59.88  
   1920x1080     60.00    60.00    50.00    59.94    24.00    23.98  
   1920x1080i    60.00    50.00    59.94  
   1600x1200     60.00  
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1280x800      59.81  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1440x576i     50.00  
   1024x768      75.08    60.00  
   1440x480i     60.00    59.94  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
DisplayPort-2 disconnected (normal left inverted right x axis y axis)
DisplayPort-3 disconnected (normal left inverted right x axis y axis)
LVDS1 connected 1280x800+4240+445 (normal left inverted right x axis y axis) 0mm x 0mm
   1280x800      60.22*+
   1024x768      60.00  
   800x600       60.32    56.25  
   640x480       59.94  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
  1024x768 (0xb7) 65.000MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  800x600 (0xbb) 40.000MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  640x480 (0xc1) 25.175MHz
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz

If I disable either one of the LVDS (the correct one is LVDS-1) the laptop monitor is shutdown.

In the installed OS only 2 monitors are detected but as i’ve said the external one doesn’t work.
In the logs there’s several of messages like this:

too many voltage retries, give up failed to train DP, aborting

So can someone help me configure my installed OS to behave like the live usb, i.e, having the external monitor working?

Thanks and kind regards,

Pedro Saraiva

This post should be in the Pre-Release/Beta forum. However, I have had no problem. You have the option of having the monitors side by side or one on top of the other. The main thing you need to do is make sure that the resolutions are compatible. Clicking on either monitor will bring up the range of resolutions available. The slider below allows you to adjust them.