I purchased a used 2005 Beaver motorhome last spring. Ever since we bought the coach the radio has given us trouble. First it would only tune with the tuning knob when turned in one direction (clockwise). Then we could only power the unit up by pushing on the front of the unit. Now it will not power up at all. I have checked the incoming power and I do have power to the two places it is supposed to (location one and three). Jerry