I had a similar situation with the HD24, but I'm responding from memory, so please bear with me. I think there might be a button on the front panel called "All Input". If I remember correctly, this button seems to put input signals on various tracks if inadvertently pressed (don't know why...apparently this button was also on my old AdatXT's, and I never knew it existed). You might just need press the "All Input" button once. Hope this helps.
