Archive December 27, 2025 by rawaha

Troubleshooting Konica Minolta bizhub C452 Jam or Misfeed at Manual Bypass Feed Section

A recurring Jam (misfeed at the manual bypass feed section) on a Konica Minolta bizhub C452 can disrupt workflow and cause frustration. This jam code indicates the machine detected a problem while picking or initially transporting paper from the multi-purpose bypass tray. Effective troubleshooting requires a systematic approach, focusing on the sensors and motors involved in this specific paper path.

Understanding Jam at the Manual Bypass Feed Section

Jam message occurs when paper fed from the manual bypass tray fails to move through the lower and upper bypass detection points within the expected timing window, or when the machine detects an abnormal sensor state during initialization or feeding.

In normal operation:

  1. The bypass feed motor (M27) drives the paper upward.
  2. Paper is detected sequentially by:
    1. Bypass lower sensor (PS36)
    1. Bypass limit sensor (PS35)
    1. Tray 1 vertical transport sensor (PS4)
  3. Sensor signals are processed by the Paper Feed / Transport Drive Board (PFTDB) and validated by the Printer Control Board (PRCB).

If any of these steps fail or occur out of sequence, Jam message is generated.

Relevant Components (Key Parts)

Before beginning, familiarize yourself with the primary parts involved:

  • Bypass Paper Feed Motor (M27): Drives the pickup and feed rollers.
  • Tray 1 Vertical Transport Sensor (PS4): The first sensor after the bypass merge; confirms paper has left the bypass area.
  • Bypass Paper Limit Sensor (PS35): Detects whether paper is present in the tray.
  • Bypass Paper Lower Sensor (PS36): Detects the leading edge of the paper shortly after pickup.
  • Paper Feed/Transport Drive Board (PFTDB): Controls the feed motor and receives signals from the sensors.
  • Printer Control Board (PRCB): The main controller that processes all sensor data.

Systematic Troubleshooting Procedure

Follow these steps in order to diagnose and resolve the issue.

Step 1: Initial Checks

  • Inspect the paper path in the bypass section for any torn pieces of paper, debris, or obstructions.
  • Ensure the paper guides in the bypass tray are set correctly and snuggly against the paper stack.
  • Use only supported paper that is in good condition (not curled, humid, or torn).
  • Check the bypass pickup and separation rollers for significant wear, contamination, or damage. Clean or replace them if necessary.

Step 2: Check Tray 1 Vertical Transport Sensor (PS4)

  • Action: Perform an I/O check for PS4 in the service mode to confirm the printer correctly sees its state (blocked/unblocked).
  • Physical Check: Manually inspect the sensor actuator for free movement and clean any dust buildup.
  • Signal Check: Verify the signal at PFTDB connector CN11-8 changes state when the sensor actuator is toggled.

Step 3: Check Bypass Paper Limit Sensor (PS35)

  • Action: Perform an I/O check for PS35. This sensor must correctly report when paper is loaded in the tray.
  • Physical Check: Ensure the sensor actuator moves freely when paper is inserted.
  • Signal Check: Verify the signal at PFTDB connector CN6<B>-10 (ON when paper is present).

Step 4: Check Bypass Paper Lower Sensor (PS36)

  • Action: Perform an I/O check for PS36. This critical sensor detects if the paper was successfully picked up and started feeding.
  • Physical Check: Inspect and clean the sensor and its actuator.
  • Signal Check: Verify the signal at PFTDB connector CN6<A>-11 changes state appropriately during a feed attempt.

Step 5: Check Bypass Paper Feed Motor (M27) Operation

  • Action: Use the service mode to activate the bypass feed motor (M27) independently and observe if it runs smoothly.
  • Check: Listen for unusual noise or observe if the motor struggles. Inspect the associated gears and drive train.
  • Control: The motor is driven via signals from the PFTDB at connector CN6<B> pins 1 through 4.

Step 6: Replace the Paper Feed/Transport Drive Board (PFTDB)

  • If all sensors and the motor check out correctly, but the problem persists, the controller for these components may be faulty. Replacing the PFTDB is the next logical step.

Step 7: Replace the Printer Control Board (PRCB)

  • If the issue remains after replacing the PFTDB, the main system board (PRCB) may have failed and require replacement. This is less common but necessary if all other components are functional.

Conclusion

Resolving a persistent Jam requires methodically testing each component in the feed sequence. Start with simple mechanical checks and cleaning, then use the machine’s I/O diagnostics to verify sensor and motor functionality. This step-by-step approach, moving from sensors to the drive board and finally the main controller, will efficiently isolate and fix the cause of the manual bypass misfeed on your bizhub C452.