Why do CD player lights dim?

I have an 07' mazda 3, my radio/cd player stopped working but it lights up. could it be from a dead battery?

• so, my radio recently stopped working, but the screen still lights up and says the time and tempurature, just no radio or cd player. then my battery died a couple days later. could that be why my radio doesnt work?

• Answer:

  I'm no expert in this, but look in your manual about an anti-theft device built into the radio. Your solution may be there.