Problem: Dual DVI radeon 9600 - second monitor on but blank

[Jez Humble]

Alex Deucher wrote:

>On Tue, 23 Nov 2004 16:46:30 -0500, Alex Deucher <alexdeucher at gmail.com> wrote:
>  
>
>>On Tue, 23 Nov 2004 21:30:12 +0000, jez humble <jez at india.com> wrote:
>>
>>
>>    
>>
>>>Hi there.
>>>
>>>I have an HIS Excalibur Platinum Radeon 9600 / RV350 AP card, which has dual DVI outputs. It works fine in Windows, but I can't get anything to display on the second monitor in Linux.
>>>
>>>I'm using the latest version of Xorg from Gentoo portage (6.8.0-r3), on a Gentoo 2004.3 release (kernel 2.6.9-r1). Architecture is AMD64.
>>>
>>>Symptoms: when I start X, the both monitors get detected and switch themselves on, and the system clearly thinks it's working as a dual head (windows stretch onto the second screen, cursor moves off the first screen). However the second screen stays resolutely black (although, as I say, it is on). I've tried changing the MonitorLayout to TMDS,TMDS, commenting all the Options in the device section. I also tried swapping the screens in the config, and the right hand side gets correctly displayed on the left hand monitor. So it looks like there is actually a problem driving the second screen.
>>>
>>>I have also tried configuring the system with Xinerama instead of MergedFB, which necessitated making both BusIDs the same, removing the comments from the Screen commands in the Device sections,  commenting all the options except MonitorLayout in the Device section, and loading Xinerama. Same symptoms.
>>>
>>>If there's anything I can do to help debug, let me know.
>>>
>>>Thanks,
>>>
>>>Jez.
>>>
>>>      
>>>
>>Looks like it may be a duplicate of bug 1666:
>>https://bugs.freedesktop.org/show_bug.cgi?id=1666
>>you may want to try th patch in bug 1559
>>    
>>
>
>As such try forcing the dpms off and see is boths head come back on
>when the heads come back on.
>
>Alex
>  
>
Thanks for your quick response Alex.

I tried the patch, and switched off dpms. Neither solved the problem. 
However, it does look like a dup of bug 1666.

Any other suggestions?

Thanks,

Jez.