It may have been a mistake but I bid and received a supposedly refurbushed i9100 Canon printerwith no ink tanks installed in the head... I'm assuming a head cleaning? The first time I ran "head alignment" there were a couple horizon streaks in the Photo Magenta rectangle... one at the top and one in the middle. The rectangle was alsoless intense than the other color rectangles. I then did a nozzle check and only a few of the Photo Magenta nozzles were apparently unplugged.
So it boils down whetherthe blue streaks and plugged nozzles point to something in particular the refurbishers may have done.
Let me also add that lots of horizontal lines in the other nozzle color test patterns are there but shifted up or down by quite some distance...