Rcaf31317 31" tv no picture when used with dvd

i cant seem to get a picture when i use an svideo cable connected to my memorex dvd player. i can hear the sound just fine but no picture the screen says unusable signal. i tried just using a red white and yellow cable without svideo and the same problem. i also switched between svideo input and video input on the menu for tv video input. nothing changes it. the dvd player works on another tv of mine.