Canon BJ-20 User Manual page 22

If the buzzer sounds before you could press the LF/FF switch,
wait for the cleaning to finish, the start from step 6 again.
The cleaning process is carried out. When it is finished, the ON LINE
7
indicator lights and a check pattern is printed.
Examine the check pattern for print quality, and repeat steps 5 to 7 if the
8
output is not clear.
To eject paper, press the ON LINE switch to turn of the ON LINE
indicator, and press and hold the LF/FF switch for one second.
If you wish to test the printer, turn off the printer. (The carriage returns to
the home position and the print head is recapped automatically.)
Cautions
Do not carry out the cleaning procedure unless it is
necessary. Excessive cleaning wastes ink.
To set the head cleaning mode properly, press the FWD
ADJ and REV ADJ switches when the carriage is
stationary.