help w220 no sound

[umedc]

hi
i have lost sound ,i think there isloose connection somewhere,as i driving it try to come on .then lost sound ,any help ,thanks

 

[AndyPCD]

It would be worth getting it stuck on a star machine and check the actual values of the audio system, as th system works in loop if one of the control units goes down it can cause the sound to stop working

 

[umedc]

just had put on star at m.b they saying it cable to areil ,but mine sat nav on command work fine but no sound?