I was facing some errors on my Printer and I called HP support rep and he helped me clean the print head... this did not help. I was using an Hp refill cartridge from a local Cartridge World store and he thought that might be the problem. He suggested I get a new Hp black cartridge and guided me to install them normally like the other three..They helped me reinserted all the ink cartridges...turned the power back on and the error message was gone and the problem was fixed.All of them are so helpful and sincere.Thank you Again! Sam and Peter.