Canon S400 Reference Manual page 130

10
When you finish entering numbers...
Click the OK button to save the settings.
Windows
Save the settings.
Macintosh
11
Click the OK button. This completes the print head alignment procedure.
Note
When you wish to switch the printer off after head alignment, always press
the POWER button to switch the printer off. If you do not switch the printer
off correctly with the POWER button, the print head alignment settings can-
not be saved.
Aligning the Print Head
Routine Maintenance 130