Stylus Photo R220 - missing color

I have an Epson Stylus Photo R220 inktjet printer that is not very heavily used. Yesterday, I wanted to print a photo and noticed that the light-migenta color is missing. I did the nozzle check and indeed, no light magenta. It is completely missing. After cleaning the head there was no improvement. I replaced all color cartridges, cleaned the head five more times, left it overnoght as the manual suggests. The next morning still the same problem. Anyone has a suggestion on how to solve this? Is it possible to replace the printhead or should I buy a new printer.? Thanks for advice.