My canon has been sitting for some time so I thought the ink dried up. Checked all the ink levels, tried the cleaning feature on the printer many, many times, to no avail. Finally took the print head out and cleaned it by soaking and using denatured alcohol. Nothing seems to help. Can not print black. Have changed cartridges 3 x and still no black printing. I am lost. Could my print head be no good? (I also change the colored ink as well and it prints).