Just sold my old Marantz 5200 to my brother. I had a problem with the menu not coming up on it so I sent it out for repair. In the meantime I had bought a new receiver. After a 6 week wait the Marantz was returned where it has been sitting on a shelf unused for about 2 months. My brother took it off my hands, and when we connected it the sub connection will not work (the sub connection is through the sub pre-amp jack). I seems to receive a signal (the subs light turns green) but emits no sound. It is not the sub - we took it back and tested it. Anyone have any ideas?