Hardware :: Using Samsung SyncMaster T240 - Screen Sleeping?

I had two of these screens connected to my 2009 MacPro, one to the Ati 4870 and the other to GeForce GT120. I was using them both together mounthes and was happy with them until this morning, when I woke my computer from slee[, I thought that my ther screen was sleeping or may be I had maximized a streaming youtube video while sleeping and it ended and it was the black screen I thought, so I pressed escape to get rid of full size mode but I noticed that the screen was working, but it was hardly noticeable, I mean, everything is all black as if the screen is turned off. I can very hardly see the wallpaper. The Problem is that when I turn it on, the screen is as it should be for 1 second then goes back to like this, even when I click on settings of the screen from the side buttons, they are dark too but I arrived to check the settings and brightness and contrast are on maximum.. and the problem is that I bought the screens when I was in France and now I am in italy, I dont know what to do.