Jam Code 66-02 is a Document Feeder (DF) paper feed section late-arrival fault on Konica Minolta bizhub machines equipped with an automatic document feeder. This code belongs to a completely different subsystem from every code covered elsewhere in this series: the DF handles original documents being fed for scanning or copying — not print paper moving through the print engine’s paper path. The 66-xx code range is dedicated specifically to the document feeder, and 66-02 addresses its own feed section — the zone from the document tray’s pickup nip to the DF’s own first downstream sensor — using the identical -02 late-arrival convention applied consistently throughout the bizhub jam code system: the original was successfully picked from the document tray, but arrived at the DF’s next detection point later than the timing window allows, rather than never arriving at all.

The official Konica Minolta description states precisely:

An original document, confirmed to have left the DF document tray’s pickup nip, was detected at the DF’s next feed-section sensor, but detection occurred after the timing window calibrated for correct feed-section transit had already elapsed.

Translated into field language: the document feeder’s pickup roller and separation mechanism engaged the top original in the document tray and successfully drove it out of the tray’s feed nip — this initial pick is confirmed by the time 66-02 can fire. What follows is a short transit through the DF’s own feed section to the next detection point, typically the sensor that confirms the original has fully cleared the separation area and is correctly positioned to continue into the DF’s main transport path toward the scanning position. If this transit takes longer than the calibrated timing window allows — even though the original is still moving the entire time — 66-02 is logged. The original was never lost; it simply did not arrive in time.

This places 66-02 in the identical diagnostic relationship to its sibling code (66-01, the DF feed section primary misfeed, where the original never arrives at all) that every other -01/-02 pair in this series shares: a component or condition that has begun to degrade does not typically fail outright on its first bad cycle — it passes through a period of reduced-but-nonzero transport capability first. During this period, the original still reaches the downstream sensor, but slower than expected, producing 66-02. If the underlying cause is not corrected, the same degradation eventually crosses the threshold into a full pick/transport failure, producing 66-01 instead. A DF producing 66-02 today is a reasonable candidate to produce 66-01 within a comparatively short time if the cause is not addressed, given that document feeders — unlike the print engine’s own paper path — process a huge variety of original conditions (aged paper, prior staple holes, handling creases, mixed stock) that accelerate wear and reveal marginal conditions faster than a controlled supply of fresh print paper would.

The DF feed section deserves a genuinely distinct diagnostic mindset from the print-paper feed sections covered elsewhere in this series, for a reason specific to what it handles: an original document is not a controlled, uniform product the way a ream of print paper is. Document trays regularly receive originals of mixed sizes, mixed weights, mixed conditions (fresh printouts alongside years-old filed documents), and — critically — originals that were never intended to be automatically fed at all: stapled sets an operator forgot to unstaple, paper-clipped bundles, torn or taped originals, and originals with folded corners or curled edges from long-term storage. Every one of these conditions is a legitimate, common contributor to 66-02 that has no real equivalent in the print engine’s paper feed diagnosis, where the media is a known, consistent, purpose-manufactured product.

Field	Details
Jam Code	66-02
System	Document Feeder (DF / ADF) — the original-document scanning input path, entirely separate from the print engine’s paper path covered elsewhere in this series. Confirm the exact DF unit fitted to the machine (integrated single-pass DF, reverse-duplex DF, or a separate scanner-mounted ADF option) against the model-specific SM, as internal layout and component naming vary
-02 suffix meaning	The original document WAS detected at the DF’s next feed-section sensor, but detection occurred outside the timing window for correct feed-section transit — a timing/delay fault, not a total pick/transport failure
Critical distinction from 66-01 (DF feed section primary misfeed)	66-01 means the original never reached the DF’s next sensor at all — the pickup/separation mechanism failed to move it, or it stalled completely within the feed section. 66-02 means the original DID arrive — pick and initial transport were not fully lost, only delayed. 66-02 is frequently an earlier-stage manifestation of the same root cause (pickup roller wear, separation pad wear) that later produces 66-01 if left unaddressed
Critical distinction from DF transport-section or DF exit-section codes	The DF feed section (covered by 66-01/66-02) is scoped specifically to the zone from the document tray pickup nip to the DF’s first downstream sensor. Faults occurring further into the DF’s transport path (carrying the original past the scanning position) or at the DF’s exit/eject point are covered under separate, distinct code ranges — refer to the model-specific SM to confirm the exact DF-related code structure, since DF code ranges are not standardized the same way the print-engine code family is across this series
Detection Logic	After the DF document tray’s own feed sensor (confirming the original has left the pickup/separation nip) triggers, the DF’s next feed-section sensor must trigger within a timing window calibrated to the known feed-section transit distance. Refer to the model-specific SM for exact sensor designations and the specific timing reference used
What the original is doing when 66-02 fires	The original’s leading edge has reached the DF’s next feed-section sensor, but later than the timing window allows. The original is generally found within the feed section itself, at or near that downstream sensor, often showing a slight buckle, skew, or drag mark consistent with a slowed-but-completed transit rather than a full stall (which would instead present as 66-01 with the original found earlier in the feed section, not having reached the sensor at all)
Key Components	DF document tray and its paper-height/presence sensing (where fitted); DF pickup roller (engages the top original in the stack); DF separation roller or separation/retard pad (prevents multiple originals from feeding together); DF feed sensor (confirms departure from the pickup/separation nip — its triggering is what starts the timing window for 66-02); DF next-stage feed-section sensor (the sensor whose late triggering defines 66-02); DF feed clutch or feed motor; DF controller interface to the main machine controller (refer to SM — DF control may be integrated with the base machine’s scanner controller or handled by a dedicated DF board depending on model)
Severity	Medium-to-High — affects scan-to-X and copy jobs using the DF; the platen (flatbed glass) remains available as an alternative for single-sheet or non-feedable originals, which is a useful customer-facing workaround while the DF fault is being resolved; may correlate with specific original types (aged, thin, or curled documents) before becoming consistent across all originals
Related Jam Codes	66-01 (DF feed section primary misfeed — original never reaches the downstream sensor at all; frequently the escalated form of an uncorrected 66-02 cause), any DF transport-section or DF exit/eject-section codes documented separately in the model-specific SM (refer to SM, as these cover zones further into the DF path beyond this article’s scope), any DF duplex-reversal-specific codes on reverse-duplex DF units (a distinct mechanism from the simplex feed section covered here, broadly analogous in concept to the print-engine duplex codes covered elsewhere in this series but mechanically separate hardware)

Model and DF Unit Coverage

Document feeder designs vary across the bizhub lineup — single-pass simplex DF units, reverse-duplex DF units capable of automatically flipping an original to scan both sides, and higher-capacity DF options with larger document trays are all in use depending on model and configuration. Because internal DF layout, sensor designations, and exact check codes vary by DF unit model, this article does not present a fabricated unit-by-unit component table with specific sensor names or connector references. Confirm the exact DF unit fitted to the machine, and use that unit’s own service manual section (DF units are frequently documented in a dedicated section of the base machine SM, or in some cases a separate DF-specific manual) for every specific component designation and diagnostic-mode check code.

Before beginning diagnosis, confirm from the applicable service manual:

• Whether the DF fitted is a simplex single-pass design or a reverse-duplex design, since this affects which components lie within the feed section scope for 66-02 versus which belong to a separate duplex-reversal mechanism
• The exact designation and physical location of the DF feed sensor and the next-stage sensor relevant to 66-02
• The DF’s rated original specification (size range, weight/thickness range, minimum and maximum original count for automatic feeding) so that originals outside specification can be identified as a contributing cause rather than assumed to be a hardware fault
• Any diagnostic-mode I/O check codes for the DF pickup/feed drive and the relevant sensors

Understanding the DF Pick-and-Feed Sequence — Why 66-02 Occurs

The DF feed section performs a function closely analogous to a print-paper source tray’s own feed section, documented in detail elsewhere in this series for the print engine — a pickup roller engages the top sheet in a stack, a separation mechanism (roller or pad) prevents additional sheets from being carried along, and a feed sensor confirms successful departure from the pickup nip. The DF’s next-stage sensor then confirms the original has cleared this initial feed zone and is correctly positioned to continue into the DF’s main transport path.

Where the DF’s feed section diverges meaningfully from a print-paper tray’s feed section is in the nature of what it feeds. A print-paper tray feeds a controlled, uniform product: fresh paper of a single specified weight and size, loaded by the customer under conditions the machine’s engineering assumes. A document tray, by contrast, regularly receives whatever originals an operator places in it — mixed sizes, mixed conditions, and critically, originals that may carry physical irregularities (staple remnants, paper-clip indentations, torn corners, curled edges from long storage, or handling creases) that a print-paper feed mechanism never has to contend with. This variability is the dominant factor distinguishing DF feed diagnosis from print-paper feed diagnosis, and it directly shapes the root cause ordering below.

Six root cause categories produce 66-02, ordered by frequency in field-installed document feeders:

• Category 1 — DF pickup roller wear or contamination (dominant hardware cause, and the direct precursor to 66-01): The DF pickup roller has glazed or accumulated contamination from repeated cycles across a huge variety of original surface types (glossy prints, matte office paper, thermal fax paper on older originals, and so on), reducing its friction below the level needed for consistently prompt pickup. This produces the same intermittent-to-consistent escalation pattern documented for print-paper pickup rollers elsewhere in this series, but DF pickup rollers frequently see a wider variety of surface conditions per cycle than a print tray roller does, which can accelerate the onset of marginal performance
• Category 2 — Original document condition (curl, creases, or surface condition slowing transit without preventing it): An original with moderate curl, a crease from prior folding, or a surface condition (such as a coated or glossy original) that reduces friction against the feed rollers can transit the feed section more slowly than a fresh, flat sheet of standard office paper — without stalling outright. This category is confirmed by correlating 66-02 onset with specific originals or original batches (older filed documents, originals recently unfolded, glossy print originals) rather than occurring uniformly across all documents fed
• Category 3 — DF separation roller/pad wear affecting feed consistency: A separation mechanism that has begun to wear may not fully prevent a degree of drag or inconsistent release on the top original, slowing its transit through the feed section without producing an outright double-feed or full stall. This is confirmed alongside Category 1 inspection, since both components are typically accessed and evaluated together
• Category 4 — Document tray loading issues (stack height, skew, or mixed originals): An original loaded skewed in the document tray, a stack that includes mixed sizes or weights, or a stack loaded above the tray’s rated capacity can all produce inconsistent feed timing for one or more originals in the set without necessarily producing a complete pick failure. This category is confirmed by inspecting how the originals were loaded and by testing with a single, confirmed-standard original from the same job
• Category 5 — DF feed sensor or next-stage sensor contamination: Paper dust or general debris on either sensor’s detection window can produce a false or delayed-reading 66-02 despite the original having transited at a normal rate. Confirmed by cleaning and retesting, and by direct sensor toggle verification in diagnostic mode
• Category 6 — DF feed clutch/motor marginal performance: A feed drive component nearing end-of-life may still function but with reduced torque, producing slower-than-nominal transit under the combined resistance of a less-than-ideal original (curl, weight) without yet failing outright. The least common cause; investigate after roller, original-condition, and sensor causes have been excluded

Step 1 — Clear the Original, Confirm the Stop Position, and Note Its Condition

1. Open the DF access cover per the model/DF-unit SM — typically a top or side cover on the DF assembly, distinct from any print-engine access point
2. Locate the original: it should be found within the feed section, at or near the next-stage sensor, generally showing evidence of a slowed-but-largely-completed transit (a slight buckle, mild skew, or a faint drag mark) rather than being stalled early in the feed nip area (which would be more consistent with 66-01)
3. Before removing the original, inspect its physical condition: is it curled, creased, glossy/coated, unusually thin or thick relative to standard office paper, or does it show evidence of a prior staple/paperclip (small holes or an indentation pattern in a corner)? Any of these observations directly informs whether Category 2 (original condition) is a likely contributor
4. Remove the original carefully, in the direction of feed travel, per the DF unit’s SM guidance
5. Note whether this was a single original or part of a multi-page set, and whether other originals in the same set fed without issue — a fault isolated to one specific original within an otherwise normal set strongly supports Category 2 (that specific original’s condition) over a hardware-wide cause

Step 2 — Review the Original(s) Involved and Correlate With Media Condition

1. If the fault recurred across multiple originals in the same job, inspect the document tray loading: stack squareness, consistency of size/weight across the stack, and stack height relative to the DF’s rated capacity
2. If the fault is specific to one or a few originals, inspect those specific sheets for curl, creases, staple/clip remnants, or surface coating that could plausibly slow their transit through the feed section
3. Where practical, re-run the same job with the flagged original(s) removed or replaced with a standard photocopy of that original, to confirm whether the original condition itself is the primary variable

Step 3 — Review DF Service History and Escalation Trajectory

1. Check whether 66-02 frequency has been increasing over recent weeks/visits — an escalating trend points toward progressive pickup roller or separation component wear (Category 1/3) and should prompt a proactive hardware inspection rather than treatment as a one-off event
2. Check the DF’s own cycle counter (where the model provides one, generally tracked separately from the print engine’s copy counter) against the DF pickup/separation roller PM replacement interval specified in the SM
3. Check for any recent DF-area service history — roller replacement, DF unit service, or repeated jam-clearing events that might correlate with the fault’s onset

Step 4 — Inspect DF Pickup Roller and Separation Mechanism

1. Per the DF unit’s SM, access the pickup roller and separation roller/pad
2. Inspect the pickup roller surface for glazing, contamination, or damage, using the same general criteria (matte vs. shiny/hard surface) established throughout this series for feed rollers, adapted to the wider variety of original surface types this roller contacts
3. Inspect the separation roller/pad for wear consistent with the criteria established for print-tray separation mechanisms elsewhere in this series
4. Clean or replace per the DF unit’s documented procedure and part reference — replace pickup and separation components together as a set where the SM recommends this, consistent with the general practice established throughout this series for paired feed/separation components
5. Run a multi-original test set after service, including at least one original with mild curl or an aged-document characteristic if available, to confirm the repair holds under realistic original conditions rather than only under ideal, fresh-paper conditions

Step 5 — Verify DF Feed Sensors in Diagnostic Mode

1. Refer to the SM to identify the DF feed sensor and next-stage sensor and their diagnostic-mode check procedures
2. With the feed path confirmed clear, verify both sensors read the correct clear state and toggle correctly on manual paper insertion/removal
3. Clean, reseat, or replace only per the SM’s guidance and documented procedure

Step 6 — Verify DF Feed Drive Operation

1. If mechanical and sensor causes do not resolve the fault, refer to the SM for the DF feed drive’s diagnostic-mode check and command it directly, observing for correct, consistent operation
2. Investigate drive component service only per the SM’s documented procedure once mechanical, original-condition, and sensor causes have been excluded

Quick Reference — Troubleshooting by Symptom

Symptom	Most Likely Cause	First Action
66-02 frequency escalating over recent weeks/visits; occurs across a wide range of originals	Progressive DF pickup roller or separation component wear — early-stage precursor to eventual 66-01	Inspect pickup roller and separation mechanism for even mild glazing/wear; replace per SM procedure rather than deferring
66-02 isolated to specific originals (curled, creased, glossy, or showing staple/clip remnants); other originals in the same set feed normally	Original document condition slowing transit without a hardware fault	Inspect flagged originals for curl, creases, or surface condition; re-test with a standard photocopy of that original in place of the questionable original where practical; advise on original condition/preparation if this is a recurring pattern with the customer’s document types
66-02 correlated with mixed-size or mixed-weight document stacks, or stacks loaded above rated capacity	Document tray loading issue	Inspect stack squareness and composition; advise on correct loading practice; retest with a uniform, correctly-loaded stack
66-02 with no clear original-condition correlation; occurs across otherwise standard originals	DF feed sensor or next-stage sensor contamination, or marginal feed drive performance	Verify both relevant sensors in diagnostic mode; clean if contaminated; investigate feed drive only after mechanical and sensor causes are excluded
66-02 already accompanied by occasional 66-01 events	Escalation has already begun — same root cause producing both severities	Treat as urgent — proceed directly to pickup roller/separation mechanism service rather than re-testing extensively

Preventing Jam Code 66-02 From Recurring

• Track DF-specific cycle count against the pickup/separation roller PM interval independently from the print engine’s own PM schedule, since DF usage volume does not necessarily correlate with print volume and can reach its own service threshold on a different timeline
• Advise customers and key operators on originals that are poor candidates for automatic feeding — heavily creased, curled, torn, or previously stapled/clipped documents — and encourage use of the platen (flatbed glass) for these specific originals rather than forcing them through the DF
• Include DF pickup and separation component inspection in every PM visit, given that this component sees a wider range of surface conditions per cycle than the equivalent print-paper feed component and can wear unpredictably relative to simple cycle count alone
• Clean DF feed-section sensors at every PM, consistent with sensor-cleaning practice established throughout this series for other transport zones
• Document DF component service history, including the DF’s own cycle counter value at replacement, in the service log

Professional Technician Summary

Jam Code 66-02 is the DF feed section late-arrival fault — an original document was successfully picked from the document tray but arrived at the DF’s next feed-section sensor later than the timing window allows, rather than never arriving at all. This is the document feeder’s own version of the -01/-02 escalation pattern documented consistently throughout this series for the print engine’s paper path, applied here to a mechanically similar but functionally distinct subsystem handling originals rather than print paper.

The single most important thing that distinguishes DF diagnosis from print-paper feed diagnosis is the variability of what is being fed. A print-paper tray feeds a controlled, uniform product; a document tray feeds whatever an operator places in it — aged documents, curled or creased originals, mixed sizes and weights, and originals that were never good candidates for automatic feeding in the first place. Before investigating pickup roller or separation mechanism hardware, always ask whether the specific originals involved in a 66-02 event have a plausible condition-based explanation, and test with a standard, fresh original to distinguish a genuine hardware cause from an original-condition cause.

When 66-02 does trace to hardware, it follows the same escalation logic established throughout this series: treat it as an early warning, not just a jam to clear. A DF producing 66-02 with increasing frequency across a range of otherwise normal originals is a strong candidate to progress to 66-01 if the pickup roller and separation mechanism are not serviced proactively.