Hello, I have a 2005 Mercedes C230 Kompressor and the head unit has no power. One day the radio went out when I started the car but the next day it worked. Now it won't power up at all. I checked all the fuses in the car including the one behind the radio. All fuses are good. I have a blinking fiber optic light from the main connector on the back of the radio and power to the CD changer. Any ideas on where I should go from here?