Hi everybody I hope someone is able to tell me the common electronic issues for the E63, 645 CI, i have a issue with NO sound, one day. all sound disappear, no cd, no radio, but the LCD monitor is working perfectly, can see that the CD is playing but there is no sound coming out. No alert tones as well, when the car is put to reverse the sensors works but no sound. I tried resetting the system but still no sound. Tried removing the negative connection of the battery for 30 mins and replacing it back, still not working. check mute button on steering, its working but still no sound. anyone who been through this and have a solutions please advised.