Having printed two Word documents, my printer gave a B203 error code, which asked me to turn the printer off and contact a service centre. My printer is a white two-year-old Pixma MG5650, and has printed almost 1,000 pages: I use cheap ink. I turned the printer off and looked on the internet to see if this condition was fixable by me. A number of people had experienced the same problem. In summary, they reported that this was a print-head problem and several gave suggestions to try this and try that, but thought that it would be necessary to buy a new printer, this being cheaper than having it repaired. After a couple of days thinking about what to do, I wanted to print another document. I decided to try it, turned the printer on: no message, so I printed the document. It was obvious that there was a problem with the blue, so I used the printer's menu to carry out a print-head clean, followed by a nozzle test print: the print showed the blue to be a little streaky. I did another head clean and print: the blue was much more streaky. I then did a deep clean, followed by a test print, and the blue had completely disappeared. After 24 hours, I carried out another deep clean, followed by a test print: the blue was still missing. I removed the cyan cartridge, which still had half the ink present. I touched the ink pad, which was moist and left ink on my finger. I shone a torch into the space vacated by the cartridge and saw that the small ink receptor pad was white. Should it be white? I checked the other colours and saw that their receptor pads were their respective colours. I put in a new cyan cartridge and did a nozzle test print, and - serendipity! - the blue was back! I reprinted the document which had showed the blue to be wrong - and it was correct this time. For each of the next seven days I printed documents and photographs. The printer is now working correctly. This solution beats sending the printer to a service centre - and beats buying another printer!