Greetings. Over the last few months my Canon MP730 has been printing with bands or white lines through the black ink and also won't print colors at times. I've tried to do ALL of the cleaning methods through the software and on the printer itself which used to help...for a time. Now it no longer helps. At this point I'm thinking it is maybe the print head? Instead of buying a new one, does anyone know how to properly clean it on this model? Many thanks!!!