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critical HP
Error Code Ink sensor warning
Indicates potential failure of ink sensors possibly caused by a cartridge or sensor malfunction.
? What Causes This
Problems with either the ink cartridges or internal measurement sensors that detect remaining ink levels.
✓ How to Fix It
Continue printing but monitor closely and replace any faulty components detected, and proceed cautiously as quality of prints may deteriorate quickly without intervention to remedy these issues.
Source: page 239 of the official manual
From the manual
This error code appears in:
HP Officejet Pro 8600 E All-in-One Printer N911a