Running a Geforce GTX 770, i5 4670, ASUS Z87-A into two Acer H6 Series 23" IPS LED HD Monitor through HDMI to DVI-D cables. I have had the first monitor for about a month with no issues at all and I just picked up the second monitor. Currently the top port is working fine on both monitors but regardless of what monitor/cable combination I plug into the second port it is not reading at all. Also if I turn on the computer with a monitor plugged into only the second port it will show the computer booting and once windows loads it turns black. Any help would be appreciated.