Keep getting a U071 error message for cartge Y
Open the printer cover and check to make sure only one Yellow cartridge is installed. If so, try the following:
Remove each of the other cartridges, one at a time as necessary and see if the error message changes. Start by lifting the cover, then wait for the printhead to move to the left so you can access the cartridges inside. Pull out one of the other cartridges ( not Y) by pushing its front tab back then close the cover. Check the display, repeat as necessary. The error should have changed to U043 (bad or missing cartridge) once you remove the bad cartridge. When you replace it, the printer should work. My guess is the Magenta or Cyan cartridge is causing your error.