An Automatic Document Feeder (ADF) that fails to feed originals is one of the most common complaints on any multifunction copier. The machine may display a “Misfeed detected” message, a “No original” warning, or simply make a clicking or grinding sound while the paper remains motionless. Unlike error codes that pinpoint a specific component, ADF feeding problems can originate anywhere from the paper path to the electrical control board.

In this guide, we will walk through every possible cause: from dirty sensors and worn pickup rollers to incorrect original specifications, broken actuators, failed torque limiters, and even logic board failures. By the end, you will have a systematic action plan to restore reliable ADF operation.

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Possible Causes

• Dirty or worn pickup, feed or separation rollers
• Glazed or contaminated separation pad / belt
• Broken or stuck sensor actuators
• Dirty glass, slit glass or document pad
• Incorrect adjustable guides (too tight or too loose)
• Paper that does not meet specifications (size, weight, finish)
• Blocked paper path (small paper piece, staple, debris)
• Failed torque limiter or one‑way clutch on the feed shaft
• ADF cover not fully closed or locked
• Defective sensors (registration, reading, exit)
• Loose or disconnected ADF cable / harness
• Failed ADF control board (DFCB) or MFP board

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Step‑by‑Step Troubleshooting

Step 1 – Check Original Specifications and Placement

Before opening the machine, rule out the simplest user‑related causes:

1. Document specification: The ADF is designed for plain paper only. Do not load photos, glossy paper, carbonless paper, perforated pages, torn documents, or sheets with wet ink or correction fluid. Wrinkled or curled originals should be flattened or placed on the glass instead.
2. Loading position: Place originals face‑up on the document tray with the top of the page going into the feeder first. Do not exceed the maximum capacity indicated by the paper limit mark.
3. Adjustable lateral guides: Slide the paper guides so they touch the edges of the original stack without bending or forcing the paper. If the guides are too loose, pages may skew. If too tight, the paper cannot feed.
4. Original glass and slit glass: A dirty slit glass (the narrow glass strip between the ADF and scanner glass) will not prevent feeding, but a dirty document pad on the ADF underside can cause false paper presence detection. Clean with a soft cloth dampened with a mild detergent.
5. ADF cover open message: Make sure the ADF is fully closed and locked. Many models have a small sensor that triggers a cover‑open error, which blocks feeding entirely.

Result: If the original loads but jams or fails after correcting these points, proceed to Step 2.

Step 2 – Clean All ADF Rollers and Sensors

Dirt and paper dust on rollers is the most common cause of pickup failure. Cleaning should be performed before ordering any replacement parts.

1. Access the rollers: Open the ADF cover (the front or top cover of the document feeder). Locate the pickup roller(s), feed roller(s), and separation roller/pad. For many models, remove the ADF paper chute to access the roller area.
2. Clean thoroughly: Use a soft, lint‑free cloth lightly moistened with isopropyl alcohol (preferably 90% or higher) or a dedicated rubber roller cleaner. Wipe each roller along its entire circumference, including the grooves. Do not use water or aggressive solvents.
3. Check the separation pad: On models with a separation pad (rather than a roller), inspect it for glazing, flat spots or contamination. Wipe it gently with alcohol. A glazed pad loses its friction and causes multiple sheets to feed at once.
4. Clean sensors and actuators: Use compressed air to blow dust away from optical sensors. Locate the paper presence sensor(s), registration sensor(s) and exit sensor(s). Carefully clean the felt pads or reflectors associated with these sensors – if they are dirty, a false jam detection will occur.
5. Clean the transport belt: On ADFs with a transport belt (common on dual‑scan feeders), wipe the belt surface gently. A dirty or slipping belt can cause documents to stop mid‑feed.

Result: If cleaning restores normal feeding, the problem was contamination. If the problem persists, proceed to Step 3.

Step 3 – Inspect Rollers for Wear and Replace If Needed

Rubber rollers wear down over time. A worn pickup roller will feel smooth and hard; a worn separation roller may have visible flat spots, cracks or missing material. Signs of roller wear include fine black dust inside the ADF and paper that does not move at all when the feed mechanism activates.

1. Remove the pickup and feed rollers: Open the roller cover. On most Bizhub ADFs, there are two pickup rollers (double tire) and one feed roller. Pull the rollers off their rotating shafts – they are usually held in place by simple tabs or clips.
2. Inspect visually and by touch: Compare the roller surface to a new roller. If the surface is shiny, glazed or hardened, it has lost its grip and must be replaced. If the rubber feels cracked or shows significant wear, replacement is necessary.
3. Replace the separation roller/pad: The separation pad (or roller) is located opposite the feed roller. On C353 and similar models, the separation pad is known to lose its sealing properties over time, causing multi‑feeds. Always replace the separation pad when you replace the pickup rollers – experienced technicians confirm that replacing only the pickup rollers will result in a callback until the separation pad is also renewed.
4. Replace rollers as a set: For reliable operation, replace the pickup roller(s), feed roller, and separation pad together. Mixing old and new components often introduces uneven wear patterns. If available, use genuine Konica Minolta parts.

Step 4 – Check the Torque Limiter / One‑Way Clutch

On many Bizhub ADFs (especially 3‑series and 4‑series models), the feed roller is driven through a one‑way clutch or torque limiter. When this component fails, the feed roller will not turn, even if the motor runs and the shaft rotates.

1. Manual rotation test: With the ADF open and paper removed, manually rotate the shaft that drives the feed roller (clockwise when viewed from the front). The feed roller should turn with the shaft in one direction but slip freely in the opposite direction. If the roller never turns, or if it turns only in the wrong direction, the one‑way clutch is faulty.
2. Listen for clicking: When the ADF attempts to feed, you may hear a faint clicking noise if the clutch is slipping. This indicates the clutch is not engaging properly.
3. Replace the torque limiter / clutch: On DF‑610/611 feeders, a service bulletin recommends replacing the joint assembly (torque limiter) with part #4344507901 (the old part from the Bizhub 350 ADF) to permanently resolve multi‑feed issues. For other models, consult your service manual for the correct clutch part number.

Note: On some older feed units, the one‑way clutch can be saved by cleaning the shaft with fine emery cloth to restore grip, but replacement is the preferred long‑term solution.

Step 5 – Inspect Actuators and Mechanical Linkages

Small plastic actuators (arms that block optical sensors) can break or fall out of position, causing permanent jam errors and preventing feeding.

1. Check the entrance actuator: On the feed assembly, there is a small white plastic arm approximately 25–30 mm long that snaps onto the feed shaft just outside of each feed tire. If this arm is missing or installed backwards, the shaft will hit the entrance sensor at the wrong time and trigger a false jam.
2. Check the spring‑loaded guide assembly: Underneath the ADF belt unit, there is a spring‑loaded guide that swivels beside the belt roller. This guide has a felt pad that can become dusty; if it is clogged, a jam event may be incorrectly signalled.
3. Verify all felt pads and reflectors: Optical sensors rely on reflective surfaces (foil‑like patches) or felt pads. If these are dirty, the sensor cannot “see” the paper. Clean them with a dry cloth or compressed air. If the actuator is broken, replace the entire ADF section or the specific part (refer to the service manual for part numbers).

Step 6 – Adjust Roller Pressure and Stop Position (Service Mode)

Incorrect roller pressure or a maladjusted document stop position can cause feeding issues that cleaning and replacement cannot resolve. These adjustments must be performed in Service Mode.

1. Enter Service Mode: Press Stop → 0 → 0 → Stop → 0 → 1 (the exact sequence may vary; refer to your model’s service manual).
2. Access ADF adjustments: Navigate to Service Mode → ADF (or DF → Feed Adjustment).
3. Adjust separation roller pressure: On Bizhub C360i and similar models, use the menu option “Make the adjusting the pressure of the separation roller.” Increasing the pressure slightly can resolve multi‑feeds, while decreasing it can help with misfeeds on heavy paper.
4. Adjust original stop position: Under the same ADF menu, select “Make the adjustment of original stop position.” This recalibrates where the leading edge of each page stops for scanning. An incorrect stop position can cause the registration sensor to time out and trigger a misfeed code.
5. Exit Service Mode and test: After making adjustments, exit Service Mode (turn the main power switch OFF and ON) and test the ADF with a known‑good 10‑page stack of plain paper.

Step 7 – Retrieve and Interpret Jam Codes

When an ADF fails to feed, the machine stores a detailed jam code that tells you exactly which sensor timed out. This code is not always shown on the control panel.

1. Enter Service Mode (as described above).
2. View the jam history: Navigate to Service Mode → Jam History (or “Misfeed History”). Look for the most recent ADF jam event.
3. Common ADF jam codes:
   • 66‑07: A remaining sheet of paper was detected by a sensor before the job started. Often caused by a dirty or stuck sensor (registration sensor PS3, reading sensor PS4/PS6, or exit sensor PS5).
   • 66‑02: Paper detected at an unexpected timing during feeding. Common causes include a failed feed clutch or worn rollers.
   • Paper take‑up timeout: The Paper Take-Up Sensor was not unblocked after a predetermined time. This almost always points to worn pickup rollers or a broken one‑way clutch.
4. Use the code to target the right area: A code that points to the registration sensor (e.g., 66‑07 on DF‑701) means the problem is before the registration point – check the pickup and separation system. A code for the reading sensor means the paper was picked up but never reached the scanning area – check the transport belt and intermediate rollers.

For a complete list of ADF jam codes, refer to the service manual for your model. The code will significantly shorten your diagnostic time.

Step 8 – Check the ADF Cable and Control Board (ADFCB / DFCB)

If all mechanical components are clean, adjusted and functioning, the problem may be electrical. Intermittent connection or a failed control board can cause the machine to report a jam even when the path is clear.

1. Inspect the ADF cable: The flat ribbon cable or wire harness connecting the ADF to the main body can become loose, pinched, or cracked. Disconnect and reconnect the cable at both ends (ADFCB side and MFP board side). Check for bent or corroded pins.
2. Perform sensor I/O checks in Service Mode: Navigate to Service Mode → I/O Check → ADF/DF. Block and unblock each sensor (paper presence, registration, reading, exit) while watching the I/O display. The status should change from “H” (high) to “L” (low) or vice versa when the sensor is triggered. If no change occurs, the sensor is faulty or the ADFCB is not receiving the signal.
3. Test the feed motor: In the same I/O Check menu, activate the ADF feed motor and pickup motor separately. Listen for smooth operation and watch for roller movement. If the motor runs but the roller does not turn, the problem is mechanical (clutch, gear, or shaft). If the motor does not run at all, suspect the ADFCB or the motor itself.
4. Replace the ADF control board (DFCB / ADFCB): If all sensors and motors test good mechanically but the machine still reports a misfeed, the control board may be faulty. Swap the board with a known‑good unit from a donor machine if available, or order a replacement. In one reported case, a Bizhub 250 repeatedly showed a “misfeed in the doc feeder entry” even with a clear paper path; the root cause turned out to be a failed PBA control board in the ADF.
5. Replace the MFP board as a last resort: In rare cases, the main control board (MFPB) fails to communicate with the ADF correctly. The service manual for the Bizhub 42 lists changing the MFPB as a possible step before replacing the entire ADF unit. However, this is an extreme measure that should only be attempted after eliminating every other cause.

Step 9 – Check for Obstructions and Foreign Objects

A surprisingly common cause of ADF misfeeds is a tiny piece of paper, a staple, a paper clip or even an insect stuck in the paper path or blocking a sensor. These obstructions can be invisible from the outside.

1. Remove the ADF paper chute and covers: Using a service manual for guidance, remove the outer covers of the ADF to expose the entire paper path.
2. Visually inspect and blow out debris: Use a flashlight and compressed air. Look behind the pickup roller area, under the feed roller, and around each sensor. Pay special attention to the area near the registration sensor and the exit roller area, where small paper fragments often collect.
3. Check the transport belt cavity: On dual‑scan feeders, lift the transport belt and look for paper bits that have wrapped around the belt drive roller. One technician reported finding an entire Post‑It note (75×75 mm) lodged inside an ADF after days of troubleshooting.

Step 10 – Verify ADF Firmware and Update if Needed

Konica Minolta periodically releases firmware updates for the ADF controller that improve feeding reliability and correct sensor timing issues.

1. Check the current ADF firmware version in Service Mode → Firmware Version. Compare with the latest version available from your Konica Minolta service portal.
2. If an update is available: Update the ADF firmware using a USB drive and the standard firmware update procedure (detailed in the service manual). Do not skip this step if your machine is exhibiting inconsistent feeding behaviour that other diagnostics have failed to resolve.

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Summary Diagnostic Table

Symptom / Error Message	Most Likely Cause	Action
No pickup at all – rollers do not turn	Worn pickup rollers or failed one‑way clutch	Clean/replace pickup rollers; test and replace torque limiter/clutch
Paper feeds but jams immediately after entry	Dirty or glazed feed roller or separation pad	Clean feed roller; replace separation pad
Multiple sheets feed together (double‑feed)	Worn separation pad, or incorrect roller pressure	Replace separation pad; adjust separation roller pressure in Service Mode
Paper skews or feeds crooked	Adjustable guides too loose, or dirty / uneven rollers	Adjust guides; clean rollers; check for worn roller bearings
“Misfeed detected” but paper path is clear	Broken actuator, dirty sensor, or stuck foreign object	Check actuator arms; clean all sensors; remove debris from paper path
Jam code 66‑07 (DF‑632 / DF‑714)	Remaining paper detected before job start; dirty registration or exit sensor	Clean PS3, PS5, PS4/PS6; adjust original stop position
ADF makes grinding or clicking noise	Worn drive gear, broken one‑way clutch, or seized motor	Inspect gears and clutch; replace torque limiter; test motor in I/O mode
No error code but ADF never starts feeding	ADF cover open sensor not engaged; ADFCB failure	Ensure ADF fully closed; check cable connections; replace DFCB

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When to Call a Certified Technician

While the earlier steps (cleaning rollers, adjusting guides, removing small obstructions) are accessible to a knowledgeable user, the following procedures require specialised training, tools, and access to official Konica Minolta service documentation:

• Replacement of the one‑way clutch / torque limiter (requires disassembly of the feed shaft assembly)
• Service Mode adjustments for roller pressure and original stop position
• Replacing the ADF control board (DFCB) and re‑flashing its firmware
• Performing detailed I/O sensor checks and interpreting service logs
• Replacing the MFP board when ADF communication is at fault
• Disassembling the ADF to access buried sensors and deeply lodged foreign objects

If you have followed this guide and your ADF still does not feed reliably, contact a certified Konica Minolta technician. Operating a machine with an unresolved feeding problem may lead to document damage or further internal damage to the ADF.

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Conclusion

An ADF that refuses to feed originals is almost never a total mystery. By far the most common causes are dirty or worn pickup rollers, a glazed separation pad, and contaminated sensors – all of which can be resolved with cleaning and routine part replacement. However, when basic cleaning fails, the diagnostic path must go deeper: checking the one‑way clutch, verifying actuators, adjusting roller pressure in Service Mode, interpreting jam codes, and finally testing the ADF control board.

With the systematic, step‑by‑step approach outlined in this guide, you can quickly isolate the fault and restore your Bizhub’s document feeder to full, reliable operation.