I am unable to change the band on the AM tuner either by remote or by front pannel buttons. The up/down buttons on the 990 don't do anything to change the frequency and a direct input causes the unit to default back to the 520kHz frequency after a couple of seconds.

The FM section works fine. I am able to change frequencies and set up my presets with no problems.

Any idea what I'm doing wrong with the AM tuner section?