After I upgraded to 12.04, my second monitor is detected (in display settings), but will not power on.

I have scoured the Internet and forums for a solution and I can't find anything. I have found a couple people with the same problem, but never a solution for it.

I am no expert, but I'm certainly not a noob.

My computer uses AMD Radeon 6250 graphics, but I do NOT want to use the proprietary graphics drivers. They refuse to work properly with my second monitor (they ATI drivers will only mirror screens, and I've done everything to try to fix it, and I DON't want mirrored screens) Not to mention that the default open-source video drivers seem to work much better than the proprietary anyway!

Again, Ubuntu's default video drivers work fine, and they even DETECT the second monitor (Dell 19'). I can drag stuff off the screen and put it on the 'space' of the second monitor and even a screen-shot shows that there are two monitors active; but the monitor is OFF. It will not power on. It goes into 'power-save' mode because it is not receiving a signal.

For some reason it is not getting the signal to power on, even though Ubuntu thinks the monitor is working properly.

I had this working fine on my Sony VAIO yesterday (with Radeon graphics/default Ubuntu video drivers). I upgraded to a Samsung Series 3 and now I have this issue.

I can't for the life of me figure out why the monitor is connected, detected and I have screen space for the monitor, but the screen won't turn on!

XRANDR Output:

Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192

VGA-0 connected (normal left inverted right x axis y axis)
   1440x900       59.9 +   75.0  
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  

LVDS connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm

   1366x768       60.1*+
   1280x720       59.9  
   1152x768       59.8  
   1024x768       59.9  
   800x600        59.9  
   848x480        59.7  
   720x480        59.7  
   640x480        59.4  
HDMI-0 disconnected (normal left inverted right x axis y axis)