Mercedes C250 2012 DTC D018 Most Comms Issue

[forumoto]

I have being trying to sort this error for 48 hours now, I have managed to deal with one of the error code that was D017.
Now I have: D018 - Most communication has a malfunction (ring break at position 1).
I want to know where is position one, which module between 1 and 2, even though the red light flashes from the Radio unit, showing at the Amp side, then the amp send light to the antenna, from there to the Bluetooth then back to the head unit which is the radio yet I keep getting this code, I need help...
I also want to know if the amplifier has ignition power or only B+

[mr G]

if you have xentry, try to do ring break test. it will show you which component is not getting signal

[forumoto]

Thanks for your input, but problem solved long ago..