Canon printers have print head problem notification systems built-in. A light will flash if there's a print head problem that needs attention. If the light flashes orange 11 times consecutively, there's a print head alignment problem. If it flashes five times in a row, it's a print head error. In many cases, print head problems can be rectified by following some troubleshooting steps.
Check the "Alarm/Power" light and count the number of times it's flashing to determine if there is a print head error.
Open the printer cover and allow the printer cartridges to centre. Remove all the ink tanks. Unclip the print head with the blue lever and reseat it. Snap it in, put the tanks back in, and close the lid. Turn the printer off and then on again.
Run a print test to verify the print quality is acceptable and that the ink is ejecting satisfactorily from the nozzles. Press and hold the "Resume/Cancel" button. The power lamp will flash twice. Release the button and the test page will print. Take a look at the output.
Perform deep cleaning if the output in the test is unacceptable. Enter the printer properties dialogue box in the "Printers" folder on the computer and choose the "Maintenance" tab from the printer properties dialogue box. Choose "Deep Cleaning" and then "Execute." Perform deep cleaning a couple of times if necessary.
Replace the ink cartridge if you continue to get unsatisfactory results for a particular colour ink. Open the lid, allow the print head to centre. Remove the ink cartridge. Insert a new one into the printer. Close the cover and allow the printer to reset itself.