djm 250w problems

hello friends ... I have almost the same problem ... suddenly the sound is muted for .... .... without any sign .... so if I turn the microphone button or any of the channels A or B from one side to the other ... it returns the sound ... would be problem in connector of the source? because it is new ... used once and it happened ... I need help ... I bought the pioneer center in Paraguay and came completely sealed without any damage .... my name is marcos and I'm from Brazil