I have a GTX 960 which has 3 displayports and only 1 HDMI. I already have 2 monitors, one of which uses the DVI port, and the other the HDMI. I am trying to use a third one with an HDMI cable, so I bought this adapter. When I try to use it, there is no input. I tried it out with my other monitor, and it still didn't work. Is this a problem with the adapter or am I doing something wrong?