I have a kenwood model eleven. both channels work and all the meters and lights work. the problem is that it will play FM radio but it won't play any other source. neither aux or the two phono inputs work. If I change to another source like aux, it still plays the FM radio. If I switch to either tape monitor A or B I can get something to play through the input of the tape jacks. The tape monitor B plays fine but Tape monitor A only plays one channel. I have tried cleaning all the pots and source selector switch to no avail. any clue?