I have a 2009 350 CLK , the Radio shows the stations and has power , no sound for the radio , Sat radio or phone . I saw different procedures that people have tried , discount the battery , remove fuse 64 then reinstall , etc. nothing ! Some people have said the Amp is out. Where is the amp ?

 

After poking around I found the Amp in the trunk on the passenger side under the trunk liner . Actually easy to remove when you pull the trunk liner back.
What I found was not pretty . After pulling it out and unscrewing the case ( the smell was a give away before removing the case) I could see the capacitors on the circuit board were completely fried. Got hot enough to lift the printed circuit off the board.
I was not shocked after calling Mercedes and finding out a new amp was 1400. plus a 600. dollar core charge. I didn't bother to find out what the labor charge would be .
Got lucky when I found a preowned amp ( exact match ) on the internet . Got lucky again that the seller was within 15 minute drive from me. ( 130.00 )
Hooked it up and I was back in business. Got old fast singing to myself . Lol .
Just posting this in case someone has a similar issue. Happy motoring for now .