Why is everything in dash board including lights off rest of car work fine

Do your gauges work? If speedo and tach and gas gauge work. Then it is most likely the light tubing is bad. Mercedes had a recall on some of their instrument clusters in 2006. You can check online to verify your VIN and part number is included in the recall. Other wise you can remove the instrument cluster and send it to companies that repair the lighting. If the gauges and lights aren't working then you may have to buy new instrument cluster.