Dual monitors not working - xrandr shows both

Question

I have two monitors plugged into my PC, one of the monitors is working but the other stays blank. If I boot into Windows both monitors then work perfectly.

This is the output of xrandx -q

colin@colin:~$ xrandr -q
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 8192 x 8192
DVI-I-1 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 473mm x 296mm
   1680x1050      60.0*+
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
DVI-I-2 connected 1680x1050+0+0 (normal left inverted right x axis y axis) 473mm x 296mm
   1680x1050      59.9*+
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  

What is the problem with my second monitor?

N.B. - Both monitors where working fine before I changed desks.

Answer 1

You should identify your second monitor in /etc/X11/xorg.conf. You need create two screens (Section "ServerLayout") on that, map those screens on monitors (Section "Screen") and map those monitors to your graphic card device (Section "Screen"). Good luck.

Answer 2

In the end I got this working by installing more recent nvidia drivers and following this guide: https://gist.github.com/matthewhartman/8382817