Electronics Repair Questions? Ask an Electronics Technician
Hello, What's the model number off of the back of the TV you're trying to control volume and MUTE on?
The volume and MUTE functions are all processed in the TV itself- so the remote needs to access the TV. In many cases it simply needs to be programmed. However it could also be a TV issue.
Let me know IF there is currently sound from the cable box on the TV. Details are paramount in solving problems like this.