connected macbook pro to external monitor (tried this with 2 different external monitors) external monitor stayed black went to system preferences-displays- macbook was set for mirroring. mirroring did not occur. unset for mirroring- extend did not occur- reset for mirroring- nothing happened. hit detect displays- nothing else happened. tried with and without dvi adapter- vga analog- and the macbook still doesn't like the external monitors. could it be that the video card is bad? or the connector?