Two things that work : 1) go under Advanced printer settings and change everything to black or gray scale. This will allow you to print in black if your color cartridges are empty. 2) take out the black ink cartridge and use a small stiff paint brush and brush the printer head ( looks like a little round mesh metal screen) I went back-and-forth and in a circular motion several times and then replaced the ink cartridge. A little dab of rubbing alcohol may help.