Greetings:
  
 A user has told me that rather suddenly, "banding" is appearing on
color photo printouts on both printers.

 I've tried the following:
 
 1. Changing the USB cable to a better quality one.
 2. Making sure the ink carts and photo paper are original/manufacturer 
    recommended.
 3. Repeatedly using the printers' built-in nozzle cleaning and head
alignment utilities.
 4. Changing USB port from an add-in card to one of the "main" ports.
 
 Can anyone else suggest additional ideas to combat the banding?