My GRE PSR 500 won't scan at all. It indicates it's scanning .But seems "stuck" on one object, even though it shows it's scanning. Secondly. When I do a search for NOAA frequencies that I know to be active in the area. It won't pick anything up, no audio at all. When I use the keypad it does BEEP . But that's all it does. What steps, if any, can I do to correct this problem?