My 2006 CLK350 has the Navigation DVD and audio CD players. The Navigation DVD player stopped taking the CD last month so I disconnected the battery for 60 minutes and powered the unit back up. Now I only get the Mercedes Benz logo on the screen and it stays on as long at the unit is powered. Nothing else. Nothing will function now. Is there any way to get the COMAND unit to go back to normal? I want to keep the original unit. Also I wondered how I should disable this COMAND unit and still drive the car if I have to.