I have an AMD Radeon R9 270 graphics card with 2 GB of memory that came in my Dell XPS 8700 desktop computer. I am running Windows 7 Service Pack 1. I have three monitors connected to my graphics card.
A Samsung 23" LCD flat panel connected to the card via the DVI connector.
A Samsung 24" LCD flat panel connected to the card via the Display Port connector using an active Accell DVI to Display Port connector.
A Samsung 23" LCD flat panel connected to the card via the HDMI connector.
Until two weeks ago this setup was working perfectly for over a year. All of a sudden, after a reboot one day, I can not get all three monitors to work anymore. After playing around with connections to different monitors, I thought maybe the active Accell Display Port connector was bad. I bought another one, this time a "better" one from Accell which has a USB power connector as well, and tried it, but it doesn't work either.
All three monitors work fine if I plug them in singly to the card. Any two monitors work fine if I plug them in to any two of the connectors. If I plug all three in, I can't get anything on one of the three monitors. It acts as if there is no connection on one of the monitors.
In the layout described above, the monitor connected to the Display Port and the one connected to the HDMI connector work, but not the one connected to the DVI connector.
Any ideas what I am doing wrong? Any help is appreciated.