Read some of the other threads regarding missing black ink. For me, right after doing an black ink switch I noticed the print was not right. Nozzle check showed only 7 carts printed, no black. Manually switching inks to the other black also only had 7 carts printing. That was yesterday. Today I decided to do a power cleaning and now they both work. Not sure what a power cleaning would do unless the common ink line was clogged? I guess I shouldn't look a gift horse in the mouth!