One connection not displaying

I have a kvm switch with 4 different computers/servers attached to it. The fourth connection is the one that is giving me problems (but also does not work on any other port). Everything is good in terms of connections as the light is not blinking when I switch to the fourth port. I plugged in a regular monitor cable in to see if I could get any video but I do not. Likewise, the display works when the computer is connected to a monitor standalone. When I connect what was in connection 3 into connection 4 I get video so I dont think the switch is the problem. I am under the impression that a regular monitor cable (non-kvm) should give me video without keyboard or mouse functionality? Thanks.