Kenwood Car stereo won't turn on. It's hooked up correctly but it won't light up.?

[2 Dope Tyler]

The other day I was listening to it then it got all dim so I took the faceplate off and put it back on and it wouldn't turn on. I took it back to best buy where I bought it and they hooked it up there and it worked. I don't know why it won't work in my car anyone know?