My R3000 has recently started leaving thick lines of magenta ink on my prints. See a photo below or here
It is an intermittent problem, but has become more frequent recently. It first happened last month, and after cleaning the printer and replacing my magenta and light magenta refillable carts with store-bought ones, the problem went away, so I thought I needed to replace my refillable carts which were nearing the two-year old mark. After replacing with new refillable carts, though, the problem has returned.
These are not smears, like you might get if the underside of the print head is dirty - they are thick lines, about 1 inch long and maybe 1/16th inch wide. On either side of the print, sometimes near the top, sometimes near the bottom.
Can anyone give me an idea of what is going on and how I might remedy this?
Thanks in advance,