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critical HP
Error Code Printhead Icon ( ) blinking
Left icon indicates a problem with the tri-color printhead. Right icon for black printhead.
? What Causes This
Print quality issues, printhead blockages or age related problems can cause this indicator to blink.
✓ How to Fix It
Perform ink tank maintenance as needed. Visit www.support.hp.com if issue persists and contact HP support for possible replacement.
Source: page 2 of the official manual
From the manual
This error code appears in:
HP Ink Tank 315