component to vga cable not giving video I bought these composite to vga cables to go from the YPbPr ports on these dvd players to a "standard" lcd monitor's vga port.  

Unfortunately, they don't work. The best results I can get are green and blue colors to come through on any given monitor.  Other monitors don't show any output at all.

This sort of thing should work, right?   Any help/advice is really appreciated.
VGA is RGBHV (horizontal and vertical sync) not YPbPr so without active adapting hardware, it isn't going to work.  The formats are not compatible as the addressing information is missing.    You might be able to find a dual mode monitor that has support for both formats on the connector (some video mixers do for example), but it would be luck of the draw and pretty rare.