Hello folks, I have a Merc '99 E 200 petrol Avantgarde.So, I once or twice pulled the battery out, and I can't type in the code in the radio.It also has a navigation,the model of radio is BP 4902.(original Mercedes Becker radio).I cant type in the numbers i can only turn it on or off.when i turn it on it says " CODE " and the letter C blinks non-stop.What should I do , i have a code but I cant type it in the radio won accept any button except ON.Many thanks.I checked if i have a constant + from the battery and i have it.please help im desperate.