I am about 40% through each of the four toner cartridges: B&W, Cyan, Magenta, and Yellow. Up to now, I have had no problems getting clean B&W or color prints (from the computer) or copies from the feeder or glass-top.
But now I get an irregular pattern of cyan spotting all down the left print side. Again, there is no repeating pattern that can be tied to the circumference of any roller unit (drum, feeder, etc.). It happens every time I print or copy.
But I just tried selecting Color Copy of a clean B&W document I placed on the glass. And there are absolutely no blue spots at all. Then I selected B&W Copy or the same clean document, and the spots are back. I get the same results if I feed the document through the feeder: spots for B&W copy, clean for color copy.
What could be causing this phenomenon and how do I fix/clean it?
If you are getting random blue dots on your prints, you can try reseating the toner cartridges and inspecting the inside of the printer for any loose toner powder that you can wipe up with a damp cloth. Once that is complete or if the inside is clear, you an try cleaning the fixing assembly or the ITB.
If that does not resolve the issue, it looks like the printer needs service. You can contact our support team at 1-800-652-2666 or you can sing into your MyCanon account to check you service options.