


in order to understand who is guilty, you must first try to flush the print head - drip the washing liquid from above onto the nozzle for the black cartridge. if the liquid goes bad - flush the head. if the liquid goes well - look at the ink pumping system and the place where the head is parked.
and also - if you do not really understand what to do, look for information on the Internet in your own language - this is better than my explanation curves. Well, remember - there is always a risk in such matters of spoiling the printer - be careful.