Kenwood Ddx512cd/dvd Screen Doesnt Come On?any Help?

[pete rock]

just purchased a kenwood ddx-512 double din cd dvd player.hooked up with the red black and yellow wires power, ignition, and ground wires.just to see if it powers up and functions before wiring everything else up.i hooked up the harnesses to test it out and the buttons light up but the scren doesnt come on??am i missing something?did i do soemthing wrong?is the unit just defective?any and all help is much appreciated thank you