My Yellow ink cartridge keeps being contaminated with the Cyan ink (turning the ink green). I have replaced the yellow cartridge with a new one, ran multiple (20!) full-page yellow prints and it eventually clears up. after a few days - a week? and it starts printing green again. The other colors seem to print normally in test, but any picture or color that uses Yellow comes out muddy. Examining the yellow cartridge the ink at the port is green. It acts like cyan ink is back flowing into the yellow cartridge. I’ve replaced the yellow cartridge twice (and the cyan once - even though it shows no contamination) yet the problem keeps returning. My next guess is to disassemble the print head. Any thoughts?