Archive December 27, 2025 by rawaha

Troubleshooting Konica Minolta bizhub C450P Jam at Tray 1 Take-up, 2nd Image Transfer, and Fusing Sections

A paper jam spanning the Tray 1 take-up, 2nd image transfer, and fusing sections on the Konica Minolta bizhub C450P represents a complex fault that can originate from multiple points in the mid-to-late paper path. This jam code indicates the paper successfully fed from Tray 1 but then failed to progress through the registration, transfer, or fusing stages within strict timing windows. Successful diagnosis requires a clear understanding of the machine’s speed-dependent logic and methodical verification of the sensors and clutches that govern this critical path.

Understanding the Jam Detection

The machine’s jam detection is sophisticated, varying by system speed and location. The specific error message will guide your initial focus:

1. 2nd Image Transfer or Fusing Misfeed Detection:

  • The paper fails to reach the Exit Sensor (PC30) on time after registration starts.
  • The Registration Roller Sensor (PC28) fails to unblock after being blocked (paper sticks post-registration).

2. Tray 1 Take-up Misfeed Detection (Speed-Dependent):

  • At 60 mm/s or 165 mm/s: Paper does not block the Registration Roller Sensor (PC28) on time after the Tray 1 clutch engages.
  • At 215 mm/s (High Speed): Paper does not block the OHP Sensor (PC27) on time after the Tray 1 clutch engages.

3. Misfeed from Delayed Sensor Deactivation:

  • Paper remains blocking either PC28 (at 60/165 mm/s) or PC27 (at 215 mm/s) for too long, indicating a transport stall or hesitation immediately after registration.

4. Detection of Paper Left in Path:

  • Sensors PC28, PC27, or the Tray 1 Double Feed Sensor (PC1) are found to be blocked during machine initialization, signaling leftover debris or a faulty sensor.

Relevant Components (Key Parts)

Focus your diagnosis on these sensors and actuators:

  • Tray 1 Double Feed Sensor (PC1): Located near the tray exit; detects paper presence and potential multi-feeds.
  • Registration Roller Sensor (PC28): The primary sensor for timing the paper’s entry into the image transfer zone.
  • OHP Sensor (PC27): An alternate timing sensor used during high-speed operation.
  • Exit Sensor (PC30): The final sensor before the output tray; confirms paper passed through the fuser.
  • Control Board (PWB-MC): The main controller that processes all sensor signals.
  • Registration Roller Clutch (CL3): Engages the registration rollers.
  • Tray 1 Paper Feed Clutch (CL1): Engages the Tray 1 pickup mechanism.

Systematic Troubleshooting Procedure

Follow this sequence to isolate the fault. Note the operational speed of the machine when the jam occurs, as it dictates which sensor (PC27 or PC28) is most relevant.

Step 1: Initial Physical Checks

  • Power off the printer and thoroughly inspect the entire paper path from the Tray 1 exit through the registration assembly, transfer belt, and fuser unit.
  • Remove any torn paper, debris, or foreign objects. Pay special attention to the registration roller area and the fuser entrance.
  • Check the registration rollers and the fuser entrance guide for wear, contamination, or damage. Clean or replace as necessary.

Step 2: Check Tray 1 Double Feed Sensor (PC1)

  • Action: Perform an I/O check for PC1 in Service Mode.
  • Physical Check: Ensure its actuator moves freely.
  • Signal: Verify the signal at PWB-MC PJ22-8 is ON when the sensor is blocked.

Step 3: Check Registration Roller Sensor (PC28)

  • Action: Perform an I/O check for PC28. This is a critical sensor for most speeds.
  • Physical Check: Inspect the sensor and actuator for smooth operation near the registration rollers.
  • Signal: Verify the signal at PWB-MC PJ24-6 toggles correctly.

Step 4: Check Exit Sensor (PC30)

  • Action: Perform an I/O check for PC30.
  • Physical Check: Locate the sensor near the fuser exit. Check the actuator.
  • Signal: Verify the signal at PWB-MC PJ24-12.

Step 5: Check OHP Sensor (PC27)

  • Action: Perform an I/O check for PC27. This is crucial for diagnosing 215 mm/s jams.
  • Physical Check: Find this sensor, often located near the registration area.
  • Signal: Verify the signal at PWB-MC PJ24-2.

Step 6: Check Registration Roller Clutch (CL3) Operation

  • Action: Use the actuator test in Service Mode to energize CL3.
  • Observation: Listen for an audible click and observe if the registration rollers attempt to turn. A faulty clutch will prevent paper from being advanced into the transfer zone.
  • Control Signal: Activated via PWB-MC PJ24-14.

Step 7: Check Tray 1 Paper Feed Clutch (CL1) Operation

  • Action: Use the actuator test to energize CL1.
  • Observation: Listen for its engagement. A failure here would cause a primary Tray 1 take-up jam by not feeding paper to the subsequent sensors.
  • Control Signal: Activated via PWB-MC PJ14-3.

Step 8: Change the Main Control Board (PWB-MC)

  • If all sensors and clutches test correctly within specifications, the root cause is likely the main control board (PWB-MC), which processes the timing logic and commands. Replacing this board is the final step.

Conclusion

Resolving this combined jam scenario on the bizhub C450P demands careful attention to the machine’s operating speed to interpret the error correctly. The diagnostic flow should progress from verifying all involved sensors—particularly the speed-specific ones (PC27, PC28)—to testing the clutches (CL1, CL3) that drive the paper. Only after confirming the health of these components should the main control board be replaced. This structured approach ensures an accurate and efficient repair, restoring reliable paper passage through the printer’s core imaging and fusing sections.