Canon S400 Reference Manual page 112

4
When the confirmation message appears, make sure that the printer is
switched on then click the OK button. Print head cleaning begins. (It takes
about a few minutes until print head cleaning is completed and the POWER
lamp stops flashing.)
5
Print a nozzle check pattern to confirm the success of print head deep
cleaning.
If the deep cleaning had no effect, perform normal print head cleaning and
Note
deep print head cleaning again. After cleaning the print head up to five
times, if the nozzle check pattern is not satisfactory, the print heads may be
worn out and the BJ Cartridge must be replaced.
Printing a Nozzle Check Pattern
Replacing the BJ Cartridge
Cleaning the Print Head
Routine Maintenance 112