Hi rchsts,
The problem seems to be with the cartridge holder (print head), to confirm that, check if there is ink blocked on the print head, I suggest you to use a lint free cloth to clean the nozzle of the ink cartridges and also clean the part on the print head where the nozzle of the ink cartridges contacts it.
If the issue persists, try a new color ink cartridge, try aligning and cleaning the new color ink cartridges and make a copy from the printer.
If the problem persists the print head needs to be replaced.
Please reply with results.