Hook up of new dvd player to comcast cable box

Question

My aunt just bought a Sony CD/DVD Player and asked me to hook it up to her GE television that is older and does not have any hook ins except for the cable line on the back (nothing else!) She wants me to hook it up through her cable box so I did so by hooking up the audio and video cables (red white and yellow) and still have nothing. The DVD player itself has component video out and coaxal things but the cable box only has s video and more cable rf things... I would appreciate any help I could get!!! Thank you!!!