Same thing happened to my MG6220. Found this solution ... your large blank ink tank is the problem. If deep cleaning, etc. doesn't work, it is probably a circuit board problem. You can still print black, but must use the smaller blank ink tank. You do this by going into your printer settings and changing the media type to Glossy Photo Paper. Click the box at the bottom left that says "Always Print with Current Settings." This tells the printer to use the small black ink tank instead of the large one. Yes, you will not be able to use the large tank but it will allow you to print.
My printer gave the dreaded U052 error "the print head is not correct; install the correct print head." All cleaning, etc. failed and I ended up purchasing a new print head. I thought this was the fix, but noticed that when I printed a black and white document from Word, it printed a blank page. If I printed a color picture, it printed fine. I bought some more large black ink tanks thinking that I had a bad one. However, this did not fix it either. It was another forum user that provided the answer above and it works fine now. Still means I have a problem with the printer and it may be on its way out, but it's a free fix for now.
