Post-Head Paper Sensor paper jam error

Error code
  • 77 Post-Head Paper Sensor paper jam error
Occurrence condition
  • The Post-Head Paper Sensor detected paper when the power was turned ON, when the cover was closed, or when the product recovered from the power saving mode.
Assumed cause
  • Foreign objects or pieces of paper in the paper transport path
  • The Post-Head Paper Sensor has a dirty surface, has fallen off, or is faulty.
  • Mechanical control board failure
Related parts
  • Post-Head Paper Sensor
  • Post-Belt Guide Unit
Troubleshooting
Step Confirmation and action YES NO
1

Check paper transport path

Is there any foreign matter, paper chips, etc. in the paper transport path?

Remove any foreign objects or pieces of paper

Go to step 2
2

Check the operation of the Post-Head Paper Sensor

Check the operation of the Post-Head Paper Sensor with the diagnostic function.

Does the signal change between when the paper is placed and when it is not?

 End Go to step 3
3

Check the Post-Head Paper Sensor for installation, dirt, and connector connection

Is the Post-Head Paper Sensor installed improperly? Is there dirt on the sensor? Is the connector not fully inserted?

Is the relay connector on the Front Frame side not fully inserted?

 Clean the sensor surface, or fully insert the connector.

Replace sequentially

  • Post-Belt Guide Unit
  • Mechanical control board