Debian – Second monitor detected but not receiving signal

atidebianmulti-monitor

I'm at my wit's end trying to figure this one out.

I have an ATI Radeon X1600 (DMS-59 connector with DMS-59 to dual-DVI adapter). I'm trying to get dual monitors working properly. So far, I've tried a few different Debian-based distributions. The only one I can get to properly display on both monitors is Backtrack 5 R3.

The problem: both monitors are detected by xrandr, and all settings look exactly the same. However, one monitor will not come out of standby. It doesn't appear to ever receive a signal. I've even changed the display layout in the System Settings. The screen size is correct, and the positioning is correct. I can even move the mouse to the second monitor, but it just stays in standby mode.

Any ideas?

EDIT
Output of xrandr follows:

~# xrandr
Screen 0: minimum 320 x 200, current 2880 x 900, maximum 8192 x 8192
DVI-0 connected 1440x900+1440+0 (normal left inverted right x axis y axis) 408mm x 255mm
   1440x900       59.9*+   75.0  
   1280x1024      75.0     60.0  
   1280x960       60.0  
   1366x768       60.0  
   1360x768       60.0  
   1280x800       74.9     59.9  
   1152x864       75.0  
   1280x768       74.9     60.0  
   1024x768       75.1     70.1     60.0  
   1024x576       60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   848x480        60.0  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  
S-video disconnected (normal left inverted right x axis y axis)
DVI-1 connected 1440x900+0+0 (normal left inverted right x axis y axis) 408mm x 255mm
   1440x900       59.9*+   75.0  
   1280x1024      75.0     60.0  
   1280x960       60.0  
   1366x768       60.0  
   1360x768       60.0  
   1280x800       74.9     59.8  
   1152x864       75.0  
   1280x768       74.9     59.9  
   1024x768       75.1     70.1     60.0  
   1024x576       60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   848x480        60.0  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1

And the monitor is a Dell SE198WFPv.

Best Answer

Given you've mentioned in the comments that the display work correctly when using the distro Backtrack 5 R3 & Windows 7, I'd suggest looking through that live CD's xorg.conf file and/or just copying that file over to your Debian system.

Additionally you can bring the Debian and Backtrack xorg.conf files together on a system and perform a side-by-side diff using the command:

sdiff deb_xorg.conf bt_xorg.conf

Which might help shed some additional light on what's different about the 2 files and what key feature/configuration option the Debian systems appear to be missing.

If you're feeling really motivated you could also paste the 2 files on say http://pastebin.com/ so that others who come across this issue in the future will find this Q&A with the solution.

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