In my '92' W140 (600SEL) my radio comes on for 10 seconds, flashes "E2" one time and turns off. Hit the power button and it comes on each time and flashes "E2" and shuts right off. The "older dogs" at the local Benz shop don't have a clue. Problem started right after they scanned the computers. Any ideas? I'd like to keep the stock system if it's a simple fix.