I have an ESP 9,and my printer stopped printing black ink. I did a copy function and still no ink so I knew it was the printer and not the driver. I changed both colour and black to no avail and tried cleaning the print head with a damp cloth, also to no avail. Figuring I had nothing to lose I ran the hot tap in the kitchen and allowed the hot water to flow into the print head rinsing out each of the colours and the two blacks. You could literally see the ink residue flowing through into the sink. After a couple of minutes I gave the print head a shake, gentle wipe with paper towel and re-assembled the print head and cartridges. Colour is a bit squiffy but black is now perfect. I have that many documents to print today and tomorrow that I would have had to buy another printer. Interesting to note, our printer is located next to the fireplace and we have had the fire on more than normal. When I get the chance I will relocate the printer to a cooler more ventilated place.