I currently have two monitors hooked up to my Radeon HD 5850 - a 24" Acer, and a 22" Sceptre. For some reason, the primary monitor (Acer) works fine while the secondary monitor (Sceptre) shows a blank, black screen. The Sceptre monitor shows that it has a connection, and I can drag windows and items from one monitor to the other. When I turn the monitor off, then on, the extended desktop displays for about a second before blacking out again.
I've tried readjusting resolutions, making a "group" through ATI CCC, etc. Any changes I make result in a brief flash of the secondary monitor, before returning to a black screen.
Well, the problem may be the connectors. The Sceptre uses a VGA connector, but I obviously am using a VGA-DVI adapter to connect to the card. Both of the monitors work independently of one another. But the moment I plug the second one in, it displays the extended desktop for about a second, then vanishes.
I've tried setting the resolutions to 1680x1050 (though ATI claims you can have different resolutions anyways), but that doesn't do anything. I can't seem to find any sort of documented solution to my problem, so I'm going to assume it's a communication problem between the Sceptre and the card. I'll have to dig up a third monitor and substitute it with the Sceptre to see if it's the monitor itself that's having the issue.
My first thought was, as you pointed out, the immature HD 5xxx series drivers. But I guess time will tell.
Thanks for the response! I highly appreciate the effort!
I can tell you it is not especially the "sceptres" monitor issue. I am having a very similar problem with my "terra" screen. The graphic card recognizes it is plugged in and everything is working, just that there is a black screen. Just as it were turned off.
The difference for me is, that the screen does not work at all with the 5850 together. I have a second computer here and as soon as I plug it in there, the screen turns on showing everything and working perfectly fine. Of course I thought about the possible causes and also tried to make it the primary monitor on my main computer. Nothing. Then I also tried to plug it in without the main screen, so it is the one and only plugged in the 5850. Guess what, nothing.
My guess now is, that those new ATI graphic cards/drivers aren't capable of dealing with smaller screens which do no support HD resolution or older screens at all. I just know it is very annoying because I practically lost 200€. That however seems like a very stupid reason. So I wonder if there are any news on this issue?
PS: Details for my screens
Main screen Asus VK266H 1920x1200 plugged in via DVI
(Secondary Screen Terra 1900 V 1280x1024 plugged in via VGA-DVI adapter = black
Secondary Screen Terra 1900 V 1280x1024 plugged in via DVI directly = black
Secondary Screen Terra 1900 V 1280x1024 plugged in as only monitor via DVI direcly = black
Secondary Screen Terra 1900 V 1280x1024 plugged in at a 7600 GT on my other computer = working)