I'm not sure I know what a falcon is but if it's the same sort of set up as the 1604 I agree that you should check the dampers captops and capping station, are the ink lines full no bubbles. another thing often missed is the waste ink pipes are they clear, sometimes they get blocked and a tell tale of that is the capping station is always flooded with ink, to prevent this we soak the capping station with cleaning fluid once a week.
But I totally agree I think your problem is ink starvation have a good look round before you even consider the head, also make sure the head is sealing on the capping station OK
regards
Tel