I originally purchased two a dual monitor setup. One was perfect, the other stayed black. I tried various combinations including different inputs even computers. It stayed black. I returned that one, and ordered another. The second turns on, but the screen is blurry when scrolling. I tested the GPU by using my old monitor, which displayed perfect. Now i'm dealing with a blurry screen because I'm tired of returning these stupid things. That said, my one monitor works wonderfully.