RCA RT2911

hi. I just bought a rca rt2911 from walmart. I bring it home and start hooking it up to my old dell lcd tv i bought around 2006. I turn the tv on and there is pink and yellow strips up and down the tv with no picture of the actually program but the audio is coming out just find. I thought i bought a defective product until i plugged it into my one year old tv in the living room and it works perfect. So what would cause this to happen? im very confused!