Canon S400 Reference Manual page 111

Deep print head cleaning
Always execute normal print head cleaning first. Only when the normal
Note
print head cleaning does not correct the problem, perform deep print head
cleaning.
Windows
1
Open the Printer Properties dialogue box.
2
Click the Maintenance tab.
3
Click the print head deep cleaning icon in the Print Head Cleaning box.
Macintosh
1
Select Page Setup from the File menu.
2
Click the Utilities button.
3
Select the Print head deep cleaning icon.
Cleaning the Print Head
Routine Maintenance 111