|Assuming the print tint has changed for a previously used file that still looks OK on the screen:|
The most likely cause of tinting would be a problem with the ink cartridges. This is unusual with Canon ones but equivalents are likely to vary - possible batch or source issue. The printer itself could be defective but it is not something I have run into. There is no user adjustment on a printer to fix this symptom - just the cleaning you have already done.
As OtheHill suggested, you could try a photo program with a gray scale facility. You save a copy of the file somewhere then set the copy to gray scale with the program. This "workaround" might give normal results if it only uses the black cartridge when printing.
Always pop back and let us know the outcome - thanks
message edited by Derek