Hi Paul, welcome to the forum. When you have questions, it is usually better to start a new topic instead of continuing a very aged one like this - those easily get lost in the traffic.
As to your question, do you have the two links inserted in the line in/out sockets in the rear panel of the Beomaster? Do you have headphones you could try to see if the volume is fine there?
A faulty muting relay would not affect speaker 2 outputs.