I have a Canon GX4020 (ink tanks rather than cartridges) which I bought about 18 months ago. I've printed about 35K pages. For the last several months, the color has been going awry frequently. I clean the nozzles and it looks OK, but within a week or two (under 1000 pages, the majority B&W and all document printing) the color is off again. I've tried deep cleaning, and it doesn't seem to last notably longer than a regular cleaning. In fact, after doing a deep cleaning just now, I'm still seeing some magenta in the first yellow band of the nozzle check pattern page.
Any suggestions for getting the nozzles clean enough that they stay clean for an extended time?
