To see if it's a card limitation we have to have the exact model. If nothing else, look up DDU to remove all Graphic drivers and install just the Nvidia drivers (latest from maker.)
I have a GTX 1060 6gb and I have two different monitors which I have used before. When one monitor is only plugged in I get an image display but once I connect the second one to the GPU as well they both go black but are still on. I am connecting one by DVI and the other HDMI. When i have the DVI one connected only, also the resolution is 1920x1080. And when I try it with the HDMI one it only says that the max resolution is 1024x768.
CPU: AMD A8-7650k
GPU: GTX 1060 6gb
PSU: 500w EVGA 80+
RAM: 16gb ddr3