Make sure that the power is turned on.
Make sure that one or more sheets of A4 or Letter-sized plain paper are loaded in the cassette (lower).
Open the paper output tray.
NEXT, on the printer lcd screen
(1) Press the MENU button.
(2) Select Setup, then press the OK button.
The setup menu screen will appear.
(3) Select Maintenance, then press the OK button.
The Maintenance screen will appear.
(4) Select Print nozzle check pattern, then press the OK button.
The confirmation screen will appear.
(5) Select Yes, then press the OK button.
Please give this a try and let me know how it works out for you.