What should I do if the Ink/Printhead light and a printhead icon are blinking?

If the Alert icon, one of the Printhead icons, and the Ink/Printhead light are blinking, one of the following may have occurred: the corresponding printhead is missing, installed incorrectly, still has an orange plug or plastic tape on it, or is incompatible or damaged. To resolve the issue, make sure both printheads are properly installed, install any missing printhead, or remove and reinsert the indicated printhead after checking for any orange plug or plastic tape. Make sure you are using the correct HP printheads for your printer, and do not open the printhead latch unless instructed to do so. (Page 9)