ports are irrelevant.. the connector on the inside is probably whats loose\not connecting properly due to flexing. its still a video card, no matter what you want to call it. .VGA is just the adapter on the outside, and what i said was "much like a vga PORT".. its the same concept, one's just internal.
hooking up a monitor MAY show the same symptoms.. but if the board itself has wiggled from the mobo... it may show the same problems, it may not..