I brought HP910XL/910 Black High Yield and Cyan Magenta and Yellow ink for my computer. The black and yellow work but the Cyan and Magenta are not producing any ink at all. I will have to return it as soon as I can to hopefully get another that all the inks work. I do not blame Staples unless it had been sitting on a shelf for a long time. What is so annoying is that is not the first time this has happened.