Line Feed error or Error Code 6000

Condition: An error occurred in the LF encoder signal.
Problems and Solutions:

• Smearing or scratches on the LF / EJ slit film
  - clean the LF / EJ slit film.
• Foreign material or paper debris in the LF drive;
  - remove foreign material.
• If other solution fail, replace one off the following
  - LF / EJ slit film
  - LF / EJ timing sensor unit
  - Paper feed roller unit
  - Logic board
  - Paper feed motor