Pre-Registration Paper Sensor paper feed delay error

Error code
  • 51 Pre-Registration Paper Sensor paper feed delay error
Occurrence condition
  • The Pre-Registration Paper Sensor is already ON when sensor check begins.
  • The Pre-Registration Paper Sensor does not turn off even after the specified time has elapsed since the Regist Roller is turned on.
Assumed cause
  • Foreign objects or pieces of paper in the paper transport path
  • The Pre-Registration Paper Sensor has a dirty surface, has fallen off, or is faulty
  • The Registration Roller Clutch has fallen off or is faulty
  • The Feed 1 Roller and Feed 2 Roller have a dirty surface, have fallen off, or are faulty
  • The Feed 1 Clutch and Feed 2 Clutch have fallen off or are faulty
  • Mechanical control board failure
Related parts
  • Pre-Registration Paper Sensor
  • Registration Roller Clutch
  • Regist Unit (RESIST, UPPER, ASSY)
  • D1 Cover (Feed 1 Roller, Feed 1 Clutch)
  • Feed 2 Unit (PAPER GUIDE, FEED, LOWER, ASSY) (Feed 2 Roller, Feed 2 Clutch)
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 Pre-Registration Paper Sensor

Does the Pre-Registration Paper Sensor respond with the diagnostic function?

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

 Go to step 4 Go to step 3
3

Check the Pre-Registration Paper Sensor for installation, dirt, and connector connection

Is the Pre-Registration 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 the sensor
4

Check the Feed 1 Roller and Feed 2 Roller for dirt and installation

Are the rollers listed in the “Assumed cause” section clean and installed properly?

 Go to step 5

Clean and reinstall the paper feed rollers.
5

Check the Feed 1 Roller and Feed 2 Roller for deformation and wear

Are the rollers listed in the “Assumed cause” section deformed or worn?

Replace the worn out or deformed roller

 Go to step 6
6

Check the Registration Roller Clutch

Check the clutch operation with the diagnostic function.

Does it make an operating sound (clutch connection sound)?

 Go to step 7 Go to step 8
7

Check the Feed 1 Clutch and Feed 2 Clutch

Check the clutch operation with the diagnostic function.

Does it make an operating sound (clutch connection sound)?

 Go to step 9 Go to step 8
8

Check the malfunctioning clutch for connection

Are the connectors connecting the clutch fully inserted?

 Connect them firmly.

Replace the parts one by one.

  • Clutch
  • Regist Unit (Pre-Registration Paper Sensor)
  • Mechanical control board
9

Check the operation of the Main Unit Motor

Check the operation of the corresponding Main Unit Motor with the diagnostic function.

Is there any abnormal noise?

 Replace the gear trains or the Main Unit Motor. Replace the mechanical control board