This cable doesn't support a computer monitor video port, or Y , Cr, Cb Video. Your video source should provide a YpbPr Component Video Signal from the HD 15 video ports to use this cable.
This cable can not convert the video signal from one type to another. Both devices must be compatible with the same signal. Do not assume that this cable will work just because you have a VGA port (ie. you can't use this cable to connect your PC to a device that only accepts component video, since PCs do not output component video).