Two years ago I purchased a new system with a ATI Radeon HD 4890 1GB card.
My computer ran pretty much perfectly, even when I added a second monitor to the system.
A week ago, the second screen began flickering every so often. Or, 'flickering' is the wrong word. The screen would go dark for a second, and then turn back on. Repeat every five seconds and then work smoothly for half an hour or so before it would go dark every fifteen seconds or so. Very random in other words.
A few days ago the second screen wouldn't even turn on. Even when I click on Extend Desktop or Detect Display in the Catalyst Control Center from ATI.
And yesterday the second monitor (HP w2207h) decided not to turn on at all. Or rather; it does not detect a signal and stays dark.
I figured it had died on me. However; when switching the cables around my second monitor works perfectly and the main monitor went dark instead. In other words; I'm fairly confident there's something wrong with that particular DVI port on my graphics card.
To make things even stranger; I can connect my HDTV to the second port and it works perfectly. It's just my computer screens that don't work.
Any help would be greatly appreciated!
If it helps, my system info is:
Windows Vista 64 bit
Intel Core i7 920 Quad-Core Socket, 2.66Ghz in a main board ( Asus P6T Deluxe V2) with 6GB RAM (Corsair).
I use a HDMI cable from both my Sony HDTV and my HP screen that I plug into a converter (to make it work in the DVI port.)
I use a standard DVI cable from my Sony main screen. It usually stays in while I alternate between the TV and the HP screen on the second port.
I'm convinced it's not the cables as my HP screen works (with the DVI converter/HDMI cable) if I plug it into the main port. And vice versa; the Sony screen stops working when I plug it into the second port.
AND: The HDTV works on the second port. So it can't be the converter that is the issue. :-S
Thanks for asking! Hope this makes things clearer.
If you haven't done so, try the following:
1. Reset all CCC ( Catalyst ) config to default.
2. Reinstall the driver if #1 did not work. And if you are re-installing anyway, download the latest drivers.
Hope this helps.