asuming you are talking about YPbPr analog component video.... component inputs only work at very specific resolutions. (due to the nature of the specifications of high definition video.)
likely your tv will only display 480i, 480p, 576i, 576p... possibly 720p but unlikely 1080i, 1080p or anyhing else higher
be sure you choose progressive or interleaved to match your tv's capabilities, and 60hz. there will be lots of options in your video card software for output. one card of mine, a radion 9550, I had to enable tv resoulutions in the catalyst control panel before the output would work properly.