I have a Rangestar FS CZH 05B FM transmitter. I have used the RCA inputs on the back side for several years with no problems. In an attempt to help a local church broadcast services to parishioners in the parking lot I tried to use the mic input and audio input on the front side of the box. I can not get them to work On the screen just to the right of the frequency numbers I have the word mute. As per the manual that came with it I have gone through the power on setup several time and can not get rid of that. I imagine that mute is what is not allowing me to use the front ports. Searched the forums with no luck. Tried contacting where I purchased it and apparently they are no longer in business. I tried searching the internet and only came up with ads for purchasing one. Any suggestions?