To clean the printheads
Cleaning uses ink, so clean the printheads only when necessary.
The cleaning process takes up to 3.5 minutes. Some noise might be generated in
Control panel: Press the Setup button, select Tools, and then select Clean
Embedded Web server: Click the Device Settings tab, click Device Services in
the left pane, select Clean printheads from the drop-down list in the Print Quality
section, and then click Run Diagnostic.
Toolbox (Windows): Click the Services tab, and then click Clean Printheads
and follow the onscreen instructions.
HP Printer Utility (Mac OS): Click Clean from the Information and Support panel.