The encoder strip sensor should be replaced if/when damaged or contains dried ink which cannot be cleaned off.

The encoder strip, and sensor, acts like a bar code for the head carriage (X-axis) - constantly enabling the printer to know the position of the print head. If the sensor or the strip is dirty or damaged then the printer may be making incorrect calculations as to the position of the print head.

Problems as a result of this sensor include ghosting prints, control panel error messages and skewed printing.