Error Code C0106 appears on a wide range of Konica Minolta bizhub machines whenever the Tray 3 or Large Capacity Tray (LCT) paper feed motor produces an abnormal timing signal. It is one of the most consistent error codes in the bizhub platform — the same detection logic, the same affected components, and the same troubleshooting sequence applies across mono and colour models alike, from the compact bizhub 227 to the high-volume bizhub 658e.

This guide covers every affected model and paper unit variant, explains exactly what triggers C0106, and walks you through the correct technician-level repair procedure from connector check to board replacement.

All Affected Models

C0106 is documented across the following bizhub models. The paper unit installed alongside the machine determines which motor is affected — refer to the table below to identify your exact combination.

What Does Error Code C0106 Mean?

C0106 is a motor lock signal error. Every paper feed motor in the bizhub paper cabinet has a built-in feedback mechanism — a lock signal — that tells the PC Control Board (PCCB) whether the motor is actually running or stopped at any given moment.

The PCCB uses this lock signal to verify that the motor is correctly responding to its commands. C0106 fires when one of two signal mismatches is detected:

• The lock signal stays HIGH for longer than allowed while the motor is commanded to run — the motor appears mechanically stalled or its feedback sensor is producing a false signal
• The lock signal stays LOW for longer than allowed while the motor is stopped — the signal is stuck in the running state even though no motion has been commanded

In both cases the PCCB cannot confirm that the motor is responding correctly, so it halts the machine and logs C0106 to prevent paper misfeeds or mechanical damage.

Step 1 — Identify Your Paper Unit Before Doing Anything Else

The motor reference and connector location differ depending on which paper cabinet is installed. Using the wrong reference wastes time and risks misdiagnosis. Confirm your installed unit before starting:

• The paper unit model number is printed on a label on the front or side panel of the cabinet
• It is also recorded under Service Mode → Machine Information / Option Configuration on most models

Once confirmed, use the reference table below for your troubleshooting:

Troubleshooting Procedure

The procedure is identical regardless of which bizhub model or paper unit you have — only the motor designation (M111 vs M131) and wiring diagram reference differ. Work through all steps in order.

Step 1 — Check the Motor Harness Connector

A loose or corroded connector between the motor and the PCCB is the single most common cause of C0106 across all models and all paper unit variants. Always start here.

1. Power the machine fully OFF and unplug the power cord
2. Open the paper cabinet and locate the paper feed motor — M111 for dual-tray cabinets, M131 for LCT units
3. Trace the motor harness to its connector at PCCB CN5
4. Disconnect and firmly reseat the connector — push until it clicks into place
5. Inspect every pin in the connector housing for: bent or backed-out pins, oxidation (green or white residue), cracked or melted insulation on the harness wires
6. If oxidation is visible, clean the pins with electrical contact cleaner and a cotton swab — allow to dry fully before reconnecting
7. Also check the connector at the harness junction between the main body and the paper cabinet — on most models there is an inter-unit connector where the harness crosses between the cabinet and the main machine. Reseat this connector as well
8. Power on and test with a feed cycle from Tray 3 / LCT

If C0106 clears after reseating the connector, the root cause was a poor electrical connection. Monitor the machine — if the error returns after a few days or weeks, the connector housing itself is faulty and should be replaced rather than repeatedly reseated.

Step 2 — Inspect the Motor Mechanical Drive Coupling

Even with perfect electrical connections, a mechanical problem at the motor output can cause the lock signal to misread. A motor fighting excessive resistance will stall intermittently, producing a HIGH lock signal during a run command and triggering C0106.

1. With the machine powered OFF, manually rotate the motor coupling or the first drive gear in the paper feed train by hand
2. Rotation should feel smooth with only slight magnetic resistance from the motor windings — no binding, grinding, irregular stiffness, or sudden hard stops
3. Inspect the gear coupling between the motor output shaft and the feed drive train: look for cracked coupler hubs, stripped gear teeth, a foreign object caught in the gear mesh, or debris in the feed roller assembly
4. If you feel binding, trace the paper feed drive path to isolate the obstruction — common sources are a jammed feed roller shaft, a broken plastic coupler that slips under load, or a piece of torn paper wrapped around a roller shaft deep in the assembly
5. Resolve any mechanical obstruction completely before continuing — replacing the motor without clearing a mechanical load will result in the same error on the new motor

Step 3 — Perform a Motor Operation Check in Service Mode

With the harness confirmed good and the drive path confirmed free, verify that the motor actually responds correctly to control signals from the PCCB.

1. Enter Service Mode on your bizhub (refer to your model’s service manual for the entry procedure — typically a specific key sequence on the control panel)
2. Navigate to the motor operation / I/O check section
3. Command M111 (or M131) to run in the CW direction, then the CCW direction
4. Observe: the motor should start immediately on command, run smoothly without hesitation, and reverse direction cleanly
5. If you have a multimeter or oscilloscope, monitor pin PCCB CN5-5 during the operation check — the lock signal should transition correctly between states as the motor starts and stops
6. A motor that does not respond to service mode commands, runs erratically, or produces a lock signal that does not transition correctly confirms a motor-level fault

Step 4 — Replace the Paper Feed Motor

If Steps 1–3 confirm the connector is secure, the mechanical path is free, and the motor still fails the operation check or produces an abnormal lock signal, the motor’s internal feedback sensor has failed. This is the most common hardware failure that causes C0106 and is not repairable — the motor must be replaced.

1. Order the correct replacement motor for your unit: M111 for dual-tray cabinets (PC-1xx / PC-2xx series), M131 for LCT units (PC-4xx series)
2. Power OFF and unplug the machine before starting
3. Note the motor orientation and coupling position before removing the old motor
4. Disconnect the harness, remove the mounting screws, and carefully extract the motor
5. Install the replacement motor, ensuring the output coupling engages correctly with the drive gear — incorrect coupling engagement will produce a mechanical load that triggers the same error
6. Reconnect the harness at PCCB CN5 and confirm it is fully seated
7. Power on and run a test feed cycle — confirm C0106 does not return

Step 5 — Update / Rewrite Firmware (Where Applicable)

On some models — particularly the bizhub 368e/308e, 458e/558e/658e, and their i-series successors — a known firmware issue can cause intermittent C0106 events even when the motor and connector are in perfect condition. If you have replaced the motor and the error persists, check whether a firmware update is available for your machine.

1. Note your machine’s current firmware version from Service Mode → Machine Information → Firmware Version
2. Check the Konica Minolta service portal or contact your distributor for the latest firmware for your model
3. Apply the firmware update per the standard rewrite procedure for your model
4. After the update, run a full test cycle from Tray 3 / LCT to confirm the error does not return

Step 6 — Replace the PC Control Board (PCCB)

PCCB replacement is the final step and should only be performed after a confirmed-good replacement motor has been installed, firmware has been verified, and C0106 still persists. A PCCB fault that causes C0106 is uncommon — but when the motor driver circuit or lock signal processing logic on the board fails, no motor replacement will resolve the error.

1. Replace the PCCB with a genuine Konica Minolta replacement board for your specific model
2. After installation, enter Service Mode and run the motor operation check to verify the new board drives the motor correctly and reads the lock signal accurately
3. Run a full test print cycle including several feeds from Tray 3 / LCT to confirm the error is permanently resolved

Why You Must Not Repeatedly Reset C0106

Quick Reference — Troubleshooting by Symptom

Professional Technician Summary

Error Code C0106 is one of the most consistent and predictable errors in the Konica Minolta bizhub platform. It appears the same way, is caused by the same components, and is resolved the same way whether you are working on a bizhub 227 with a PC-113, a bizhub C364e with a PC-110, or a bizhub 658e with a PC-415.

In field practice, loose or oxidized connectors resolve the majority of C0106 cases — particularly on machines that have been moved, recently serviced, or operating in dusty or humid environments. Motor internal feedback sensor failures are the second most common cause. PCCB failures and firmware issues are uncommon and should only be considered after the motor and connectors have been thoroughly tested.

Follow the steps in order, confirm your findings before moving to the next step, and do not replace the PCCB until you have installed and tested a known-good motor. That sequence will resolve C0106 on any bizhub model efficiently and at the lowest possible parts cost.