Hello. I have 2 monitors (different resolution) working properly with my R9 270 card via 2 dvi ports. Recently, I bought a hdmi-to-vga adapter to connect the third monitor, but when I connect it- all three screens go black and even if I disconnect the cable they stay black, so I have to reset my computer without the hdmi-vga cable. Please help me understand what I'm doing wrong. Thank you for your time. Anthony