Is the black ink cartridge new? some times, Cartridges dry up and that would be why you cant print. Also you can take the cartridge and rub it on a sheet of paper; if ink smears on the paper, then you should check the holster that the ink cartridge is seated. make sure that there aren't any obstructions that would not allow the cartridge to be seated on the chip. Also make sure that you are using Cannon authorized ink and not a refurbished cartridge