Large Capacity Tray (LCT) jam codes on Konica Minolta bizhub machines cover paper feed failures that originate inside an externally attached high-capacity paper unit. Three distinct jam codes address different failure zones in the LCT path:
- Jam Code 15-01 — Primary LCT feed misfeed: the paper leading edge does not activate the LCT paper feed sensor (PS3) within the allowed time after the LCT starts feeding. The fault is inside the LCT unit itself — either at the pickup roller or within the LCT’s own feed drive
- Jam Code 16-01 — Transfer LCT (PC-410 / PC-415 / PC-416 / PC-417 internal LCT) feed/transport misfeed: the vertical transport sensor inside the internal LCT does not activate after the feed sensor confirms paper pickup. The fault is in the LCT’s vertical transport drive
- Jam Code 17-20 — LCT transport section misfeed: the LCT paper feed sensor (PS3) activated correctly (paper left the LCT), but the Tray 2 vertical transport sensor (PS12 or PS19) in the base machine did not activate within the allowed time. The fault is in the inter-unit transport path between the LCT exit and the base machine’s tray 2 sensor
All three codes involve the same fundamental LCT architecture but fail at different points in the paper’s journey — understanding which code is displayed tells you immediately which zone of the system to examine first. This article covers all three codes, all compatible LCT models, and the complete diagnostic procedure for each.
| Field | 15-01 (LCT Feed) | 16-01 (Transfer LCT Transport) | 17-20 (LCT Inter-Unit Transport) |
|---|---|---|---|
| Jam Code | 15-01 | 16-01 | 17-20 |
| Fault Zone | Inside the LCT unit — paper never left the LCT feed section | Inside the internal PC-410/PC-416 LCT — paper left the feed nip but did not reach the vertical transport sensor | Between the LCT exit and the base machine Tray 2 VT sensor — paper left the LCT but stalled in the inter-unit transport path |
| Detection Logic — 15-01 | The leading edge of the paper does not turn ON the LU paper feed sensor (PS3) even after the lapse of a given period of time after the external LCT starts to feed paper | ||
| Detection Logic — 16-01 | After the transfer LCT starts to feed paper, the vertical transport sensor (PS133) is not turned ON even after the lapse of a given period of time after the leading edge of the paper has turned ON the paper feed sensor (PS132). Sub-code 16-05: PS132 itself was never activated — paper did not leave the feed nip at all | ||
| Detection Logic — 17-20 | The Tray 2 vertical transport sensor (PS12 or PS19) is not turned ON even after the set period of time has elapsed after the LU paper feed sensor (PS3) turns ON by a paper | ||
| Key LCT Units | LU-302, LU-207 (C258/C308/C368/C458/C558/C658/458e/558e/658e/368e/308e); LU-205, LU-303 (758/808/958/C659/C759); LU-302, LU-207 (C250i/C300i/C360i/750i/800i/900i); PC-410/PC-415 (internal LCT for 16-01); PC-416/PC-417 (internal LCT for 16-01 on i-series) | ||
| Key Components | LCT pickup roller (with load-adjustable spring); LCT paper feed motor (M2); LCT transport motor (M3); LCT paper feed sensor (PS3); LU drive board (LUDB); inter-unit harness between LCT and base machine; Tray 2 vertical transport motor (M7); Tray 2 vertical transport sensor (PS12/PS19); PFTDB (high-volume models), BASEB (i-series), MFPB (e-series), PCCB (internal LCT models) | ||
| Severity | High — LCT disabled; all jobs routed through the LCT are halted until the root cause is resolved | ||
| Related Codes | 15-40 (LCT image write signal timeout), 16-05 (Transfer LCT feed sensor PS132 never activated), 16-40 (Transfer LCT image write timeout), 17-20 (LCT transport section misfeed), 20-01 (Vertical transport section misfeed in base machine), C0501–C0507 (LCT lift motor abnormalities) | ||
All Compatible LCT Units, Base Machine Models, and Exact Component References
The LCT system connects to bizhub machines through two different architectural approaches. External LCT units (LU-series) are free-standing high-capacity feeders placed beside the machine and connected by a harness and mechanical coupling. Internal LCT units are the large-capacity bottom cassettes inside paper cabinets (PC-410/PC-415/PC-416/PC-417). Both types produce 15-01/16-01/17-20 but through different component paths.
Platform Group A — External LCT (LU-302 / LU-207) with MFPB / FRB / BASEB Base Machines
The LU-302 is a 3,000-sheet external LCT. The LU-207 is a 2,500-sheet external LCT. Both use the same core architecture: the LCT has its own LU Drive Board (LUDB), its own paper feed motor (M2), and communicates with the base machine through an inter-unit harness. These units produce Jam Code 15-01 when PS3 is not activated.
| Base Machine Models | LCT Unit | Feed Sensor | M2 Check Signal | Sensor Check Signal | Pickup Roller Adjustment | Base Board | Board Fuse |
|---|---|---|---|---|---|---|---|
| C258 / C308 / C368 / C458 / C558 / C658 / 368e / 308e / 458e / 558e / 658e | LU-302 / LU-207 | PS3 | LUDB CN4-5 to 8, Location: LU-207/LU-302 3-G, Check code: 28, Multi code: 33–36 | LUDB CN5-8 (ON), Location: LU-207/LU-302 4-G | Required — see Step 2 | MFPB + LUDB | PCCB F10 or F12 (where PCCB is installed) |
| C250i / C300i / C360i / 250i / 300i / 360i / 750i / 800i / 900i | LU-302 / LU-207 | PS3 | LUDB CN4-5 to 8, Location: LU-205/LU-303 3-G, Check code: 28, Multi code: 41, 44, 45 | LUDB CN5-8 (ON), Location: LU-302 4-G | Required — see Step 2 | BASEB + LUDB | PCCB F10 or F12 (where PCCB is installed) |
Platform Group B — External LCT (LU-205 / LU-303) with PFTDB Base Machines
The LU-205 is a 4,000-sheet external LCT. The LU-303 is a 3,500-sheet external LCT. On PFTDB-equipped high-volume machines, the external LCT uses both M2 (paper feed motor inside the LCT) and M3 (LCT transport motor also inside the LCT). Both codes 15-01 (PS3 not activated) and 17-20 (PS3 activated but PS12 in base machine not activated) are relevant to these units.
| Base Machine Models | LCT Unit | Feed Sensor | Tray 2 VT Sensor | M2 Check Signal | M3 Check Signal | M7 Check Signal | Base Board | Fuse |
|---|---|---|---|---|---|---|---|---|
| 758 / 808 / 958 / PRO 958 | LU-205 / LU-303 | PS3 | PS12 | LUDB CN4-5 to 8 | LUDB CN4-1 to 4, Location: LU-205/LU-303 3-G | PFTDB CN10-9 to 12, Location: 13-P | PFTDB + MFPB + LUDB | PFTDB F11, F12, F13, F15 |
| C659 / C759 | LU-205 / LU-303 | PS3 | PS12 | LUDB CN4-5 to 8, Check code: 28, Multi code: 17–20 | LUDB CN4-1 to 4, Check code: 28, Multi code: 21–24, Location: LU-205/LU-303 3-G | Check code: 28, Multi code: 13–16, PFTDB CN10-9 to 12, Location: 13-P | PFTDB + MFPB + LUDB | PFTDB F11, F12, F13, F15 |
Platform Group C — Internal LCT (PC-410 / PC-415 / PC-416 / PC-417) — Jam Code 16-01
The internal LCT is a large-capacity bottom cassette inside the PC-410 (2,500-sheet) or PC-415 / PC-416 (equivalent) paper cabinet. Unlike the external LU-series units, the internal LCT uses the same PCCB architecture as the other cabinet trays. Jam Code 16-01 is specific to this internal LCT configuration and indicates that the feed sensor (PS132) activated but the vertical transport sensor (PS133) was not activated — or in the 16-05 sub-code, PS132 itself never activated.
| Base Machine Models | LCT Cabinet | Feed Sensor | VT Sensor | Feed Motor | VT Motor | PS132 Check | PS133 Check | M131 Check | M132 Check | Board | Fuse |
|---|---|---|---|---|---|---|---|---|---|---|---|
| C258 / C308 / C368 / C458 / C558 / C658 / 458e / 558e / 658e | PC-410 / PC-415 | PS132 | PS133 | M131 | M132 | PCCB CN4-14 (ON), Location: PC-415 7-J | PCCB CN4-14 (ON) — refer to SM | Check code: 28, Multi code: 1–4, PCCB CN5-1 to 8, Location: PC-415 5-J | Check code: 28, Multi code: 5–8, PCCB CN5-9 to 16, Location: PC-415 4-J | PCCB + MFPB | PCCB IC2 |
| C250i / C300i / C360i / 750i / 800i / 900i | PC-416 / PC-417 | PS132 / PS162 | PS133 / PS153 | M131 / M152 | M132 / M151 | PC-416: PCCB CN4-14 (ON); PC-417: PS162: PCCB CN4-11, PS153: PCCB CN4-14, Location: PC-417 2-C / 3-C | Refer to SM | PC-417: M152 Check code: 28, Multi code: 51–55, PCCB CN5-1 to 8, Location: PC-417 7-K | PC-417: M151 Check code: 28, Multi code: 56–60, PCCB CN20-1 to 3, Location: PC-417 7-K | PCCB + BASEB | PCCB F4 |
ℹ️ Architecture note — external vs internal LCT: The external LU-series units (LU-205/LU-207/LU-302/LU-303) sit beside the machine on their own stand and connect through a combination of a mechanical paper guide bridge and an inter-unit harness. They have their own independent LU Drive Board (LUDB) and their own dedicated motors (M2 for paper feed, M3 for internal transport). The internal LCT units (PC-410/PC-415/PC-416/PC-417) are large-capacity cassettes inside a paper cabinet, sharing the cabinet’s PCCB with the other trays. These two architectures require completely different diagnostic approaches. Confirm which type is installed before running any service mode check.
Understanding the LCT Paper Path — From Stack to Base Machine
The LCT paper path is longer and more mechanically complex than any standard cassette tray. Understanding the full path from the paper stack to the base machine’s registration sensor is essential for correctly interpreting which jam code applies and where to focus diagnosis.
On external LU-series units, the complete paper path is:
- The LCT lift mechanism raises the paper stack (up to 4,000 sheets) until the top sheet contacts the LCT pickup roller. This mechanism uses a large-capacity elevator driven by the LCT lift motor, and the pickup roller uses an adjustable spring-loaded pressure arm — not a fixed mounting. The pickup roller contact pressure must be set within the specified range using the LCT pickup roller load adjustment procedure. Incorrect contact pressure (too light or too heavy) is one of the most common and most easily overlooked causes of 15-01
- The LCT paper feed motor (M2) drives the pickup roller and feed roller inside the LCT. Paper is separated from the stack by the feed/separation roller pair inside the unit
- The paper leading edge activates the LCT paper feed sensor (PS3) inside the LCT unit — this is the primary detection point. PS3 activation is what clears the 15-01 timer; if PS3 does not activate, 15-01 fires
- On external LCT units with a dedicated transport motor (M3): after PS3 activates, M3 (LCT transport motor) drives the paper from the LCT’s internal feed section across the paper bridge and into the base machine’s paper path. M3 failure produces 17-20 — PS3 activated but the base machine’s tray 2 sensor was never reached
- The paper enters the base machine through the LCT-to-machine paper guide bridge and is picked up by the Tray 2 vertical transport roller (driven by M7 in the base machine). The paper then activates the Tray 2 vertical transport sensor (PS12 or PS19) in the base machine — confirming that the LCT paper has successfully transferred into the main paper path
- From PS12/PS19, paper continues upward through the main paper path to the registration roller, imaging section, and fusing unit
On internal LCT units (PC-410/PC-416), the path is contained within the cabinet, using M131/M152 for feed and M132/M151 for vertical transport, with the paper ultimately entering the base machine from below through the existing inter-tray transport path.
Step 1 — Clear the Paper and Identify the Stopped Position
As with all tray jam codes, identifying exactly where the paper stopped is the most diagnostic-efficient first step. For LCT jams, the paper can stop in three distinct zones, each mapped to a specific jam code and specific component.
- Open the LCT access door (the right-side door on LU-series units, or the cabinet right-side door on PC-410/PC-416 units). Also open the base machine right-side cover if the jam message indicates paper is in the base machine’s transport section
- Remove any jammed paper carefully, always pulling in the direction of paper travel. In the LCT’s vertical transport section, paper should be pulled upward. Never tear paper inside the LCT — fragments in the narrow LCT transport path are very difficult to retrieve and cause repeat jams
- Also check the paper bridge between the LCT and the base machine — this is a frequently overlooked jam location where paper stops mid-transfer between the two units
- Note exactly where the paper stopped:
- Paper did not move at all from the LCT stack (15-01, 16-05): M2 (paper feed motor) not running, pickup roller spring pressure incorrect, pickup roller severely glazed, or LUDB has lost communication. Proceed to Steps 2–5
- Paper moved from the stack but stopped inside the LCT before reaching PS3 (15-01): M2 is running but the feed/separation roller system is not reliably driving the sheet through. Roller wear or one-way clutch slipping inside the LCT. Proceed to Step 3
- Paper exited the LCT feed section (PS3 activated) but stopped inside the LCT’s internal transport section — on PC-410/PC-416 (16-01): M132/M151 (LCT vertical transport motor) not running, or internal transport roller glazed. Proceed to Step 6
- Paper exited the LCT (PS3 activated) but stopped on the paper bridge between LCT and base machine (17-20): M3 (LCT transport motor) not running, or the paper bridge alignment is incorrect. Proceed to Step 7
- Paper crossed the bridge but stopped in the base machine’s Tray 2 VT section (17-20): M7 (Tray 2 vertical transport motor in base machine) not running. Proceed to Step 8
- Inspect the stopped paper for damage patterns:
- Paper has a heavy crease or buckle near the LCT feed nip: Paper was driven by the pickup roller but the feed roller did not turn — one-way clutch inside the LCT is slipping on a polished shaft
- Paper stopped cleanly mid-bridge with no crumpling: M3 (LCT transport motor) not running — the paper exited the LCT feed section but the internal bridge transport rollers received no drive
- Multiple sheets entered the path simultaneously: LCT separation roller or retard pad worn — replace and recheck pickup roller load adjustment
Step 2 — Perform the LCT Pickup Roller Load Adjustment
This step is unique to LCT servicing and has no equivalent in standard cassette tray maintenance. The LCT pickup roller uses an adjustable spring-pressure arm — unlike cassette tray pickup rollers, which have a fixed spring or solenoid-controlled drop. The contact pressure between the pickup roller and the top of the paper stack must be within the manufacturer’s specified range. Too light: the roller slips on the paper surface and cannot reliably pick up single sheets, especially from a full 3,000–4,000-sheet stack. Too heavy: the roller drives multiple sheets simultaneously (double-feed) and the separation mechanism is overwhelmed.
The service manual for every LCT model explicitly lists “Make the pick-up roller load adjustment of the LCT” as Step 2 in the 15-01 remedy — before any sensor or motor check. This is Konica Minolta’s own field guidance that the adjustment is the most common non-electrical cause of 15-01.
- Open the LCT unit access door to access the pickup roller assembly
- Locate the pickup roller pressure adjustment mechanism — on LU-302 and LU-207 units this is a spring tension adjuster on the pickup roller arm, typically accessible from the front-right of the LCT internal mechanism. On LU-205 and LU-303 units the adjustment is accessed similarly through the LCT’s internal access area
- Using a spring scale or by feel with reference to the service manual specification, check the downward contact pressure of the pickup roller against the top of a paper stack of approximately 500 sheets (partial stack condition — this is the most critical check height as pressure varies with stack level):
- The specified contact pressure is typically in the range of 350–600 gf (3.4–5.9 N) at the roller surface — refer to the exact model-specific service manual value as this varies between LU-302, LU-207, LU-205, and LU-303
- Pressure below the minimum: roller cannot consistently grip and lift individual sheets from the stack — primary cause of 15-01 on worn-in units
- Pressure above the maximum: roller picks multiple sheets simultaneously, overwhelming the separation mechanism and causing double-feed jams
- Adjust the spring tension adjuster to bring the pickup roller pressure within the specified range. Most models provide 3–5 adjustment positions on the spring anchor — move the spring to the next anchor position and recheck pressure with the spring scale
- After adjustment, reload approximately 500 sheets into the LCT and run a 10-page print test from the LCT. Observe the first 3–5 pages to confirm single-sheet pickup is reliable
- If the pickup roller pressure is within specification but 15-01 still occurs, the roller itself is glazed or the spring mechanism is deformed. Proceed to Step 3
⚠️ Pickup roller load adjustment is mandatory at every LCT PM. On LU-302 and LU-207 units, the pickup roller spring weakens progressively over high-volume usage. A unit that was adjusted correctly at the last PM may be below specification 150,000–200,000 LCT copies later. Always perform the load adjustment check at every PM visit — this alone prevents a significant proportion of 15-01 service calls on high-volume LCT installations.
Step 3 — Inspect and Replace the LCT Pickup Roller, Feed Roller, and Separation Roller
The LCT pickup and feed rollers wear progressively from the high sheet count that LCT installations typically process. On high-use LCT systems processing 10,000+ sheets per month, the pickup roller typically reaches end-of-life at 200,000–300,000 LCT copies.
- With the LCT access door open, inspect the pickup roller surface — it should be textured and compliant. A shiny, glazed, flat-spotted, or cracked rubber surface is the direct cause of the pickup roller failing to grip individual sheets reliably, particularly from a full stack where the paper surface is smooth and the pressure arm is at its weakest leverage angle
- Access the LCT feed assembly to inspect the feed roller and separation roller. On LU-302 and LU-207 units, the feed assembly is typically accessible after removing a cover panel on the right side of the LCT housing. Refer to the LCT-specific section of the service manual for the exact removal procedure
- Inspect:
- Feed roller: Check for glazing, flat-spotting, or cracking. The rubber surface should have visible texture and should feel slightly grippy to the touch
- Separation roller or retard pad: A rubber separation roller should resist rotation against the feed direction with light force and turn in the feed direction freely. A retard pad should have a firm, textured surface without hollowing or glazing at the contact point
- Clean all roller surfaces with a damp lint-free cloth — never use IPA or chemical solvents
- If any roller is glazed or worn, replace the complete LCT roller set (pickup, feed, and separation/retard) as a unit — individual roller replacement on a worn set produces uneven feed performance. The PM kit for the LU-302 and LU-207 includes these rollers as a set
- After roller replacement, immediately recheck and readjust the pickup roller load pressure (Step 2) — new rollers may have different contact geometry that changes the effective spring pressure at the roller-to-paper interface
Step 4 — Inspect and Reseat the LCT Inter-Unit Harness Connectors
The LCT communicates with the base machine through a multi-pin inter-unit harness that carries the 24V power supply to the LUDB, the CAN or serial communication signals between the LUDB and the base machine board, and the sensor feedback signals. A loose, damaged, or incorrectly seated inter-unit harness produces a total or intermittent loss of LCT function — no motor commands are executed, no sensor data returns, and 15-01 fires on every LCT print cycle.
- Power OFF and unplug both the base machine and the LCT unit (if the LCT has its own power switch and/or power connection)
- Locate the inter-unit harness connector between the LCT and the base machine — on LU-302 and LU-207 units this is a multi-pin connector at the rear of the LCT-to-machine connection point, typically at the rear left of the LCT where it docks against the machine. On LU-205 and LU-303 units the connection is similarly at the rear docking point
- Disconnect the inter-unit harness from both ends and inspect all pins carefully:
- Look for bent or pushed-back pins — common on units that have been detached and reconnected multiple times
- Check for corrosion or toner contamination on connector pins
- Verify the latch clip is fully engaged on both connector ends — a connector that appears seated but has not latched produces intermittent LUDB communication loss
- Also reseat all connectors on the LUDB itself — the LUDB is mounted inside the LCT housing, typically accessible after removing the LCT rear cover. Reseat the M2 motor connector, the M3 motor connector (on LU-205/LU-303), the PS3 sensor connector, and the LUDB power/communication harness connector
- Reconnect the inter-unit harness, power on, and run a 10-page LCT print test. If 15-01 clears, the harness connection was the cause. Monitor for recurrence — an intermittent connection that resolves temporarily but returns within a few power cycles indicates a degraded connector or pin that should be replaced rather than reseated
ℹ️ Critical first check when 15-01 appears immediately after the LCT was moved, serviced, or after a PM visit involving the LCT: The inter-unit harness connector is the first thing to inspect — before entering service mode or checking any mechanical component. A connector not fully reseated after the LCT was repositioned or the paper path bridge was reinstalled reproduces 15-01 on every LCT print and resolves in two minutes when the connector is properly seated. This is the most common post-PM LCT service call cause.
Step 5 — Check the LCT Paper Feed Sensor (PS3) in Service Mode
The LCT paper feed sensor (PS3) is the primary detection point for all 15-01 events. It is located inside the LCT housing at the point where paper exits the LCT’s internal feed section and enters the transport zone. A sensor that is permanently stuck in the ON (blocked) state produces 15-01 when cleared, and a sensor stuck in the OFF state never confirms paper arrival even when paper actually passes through.
- Enter Service Mode (refer to model-specific service manual for access procedure)
- Navigate to the sensor I/O check section
- Monitor PS3 at the check signal shown in the model reference table above:
- LU-302 / LU-207 (all base machines): LUDB CN5-8 (ON), Location: LU-207/LU-302 4-G
- LU-205 / LU-303 (758/808/958/C659/C759): LUDB CN5-8 (ON), Location: LU-205/LU-303 4-G
- With no paper at the PS3 position: the sensor should read OFF (unblocked)
- Manually advance a sheet of paper from the LCT tray through the feed section until the leading edge crosses the PS3 sensor beam — the sensor should switch to ON, then return to OFF when the paper is withdrawn
- Inspect:
- Sensor reads ON permanently with no paper at sensor position: A torn paper fragment from a previous jam is lodged in the PS3 beam — inspect the sensor slot inside the LCT and clear any debris. If the slot is clear and the sensor actuator flag (if present) is intact, the sensor has failed in the blocked state — replace PS3
- Sensor does not switch ON when paper is manually positioned: Check the PS3 connector to LUDB CN5. If the connector is properly seated and the sensor still does not respond, replace PS3
- Sensor switches correctly when tested manually: PS3 is functional. The fault is in M2 (feed motor), the pickup roller spring pressure, or the rollers — paper is not physically reaching PS3 during the powered feed cycle
Step 6 — Check the LCT Paper Feed Motor (M2) in Service Mode
M2 is the motor inside the LCT that drives the pickup roller and feed rollers. On all LU-series units, M2 is mounted inside the LCT housing and its drive signal comes from the LUDB. If M2 does not run, no paper movement occurs from the moment the LCT is commanded to feed — 15-01 fires immediately with no physical paper movement at the LCT feed section.
- In Service Mode, navigate to the motor load check section
- Command M2 to run using the model-specific check signal:
- C258 / C308 / C368 / C458 / C558 / C658 / 458e / 558e / 658e / 368e / 308e (LU-302/LU-207): Check code: 28, Multi code: 33, 34, 35, 36, Signal: LUDB CN4-5 to 8, Location: LU-207/LU-302 3-G
- C250i / C300i / C360i / 750i / 800i / 900i (LU-302/LU-207): Check code: 28, Multi code: 41, 44, 45, Signal: LUDB CN4-5 to 8, Location: LU-302 3-G
- C659 / C759 (LU-205/LU-303): Check code: 28, Multi code: 17, 18, 19, 20, Signal: LUDB CN4-5 to 8, Location: LU-205/LU-303 3-G
- 758 / 808 / 958 / PRO 958 (LU-205/LU-303): Signal: LUDB CN4-5 to 8, Location: LU-205/LU-303 3-G
- Observe: with the LCT access door open, the pickup roller and feed roller should visibly rotate when M2 is commanded. Listen for any unusual noise — grinding or irregular rotation indicates a failing M2 bearing or a mechanical bind in the LCT feed gear train
- Interpret:
- M2 runs and rollers turn: M2 and its drive circuit are functional. The fault is the pickup roller contact pressure (Step 2) or the roller surface condition (Step 3). Return to those steps
- M2 runs but rollers do not turn: The drive coupling between M2 and the roller shaft has failed — inspect the LCT gear train for a stripped gear or broken coupling
- M2 does not run: Check the LUDB power supply from the inter-unit harness — if LUDB has no power, no motor will run regardless of service mode commands. Check PCCB F10 or F12 (on machines with PCCB installed alongside the LCT) for continuity. If LUDB has power and M2 still does not run, check the M2 connector to LUDB CN4, test M2 winding resistance, and replace M2 if the winding is open-circuit
Step 7 — Check the LCT Transport Motor (M3) in Service Mode — LU-205 / LU-303 Models (Jam Code 17-20)
The LCT transport motor (M3) is present on LU-205 and LU-303 units and is responsible for carrying paper from the LCT’s internal feed section (past PS3) across the paper bridge and into the base machine’s Tray 2 vertical transport zone. M3 failure is the most common cause of Jam Code 17-20 — PS3 activates correctly (paper left the LCT feed section) but PS12/PS19 never activates because M3 is not driving the paper across the bridge.
- In Service Mode, navigate to the motor load check section
- Command M3 (LCT transport motor) to run using the model-specific check signal:
- C659 / C759 (LU-205/LU-303): Check code: 28, Multi code: 21, 22, 23, 24, Signal: LUDB CN4-1 to 4, Location: LU-205/LU-303 3-G
- 758 / 808 / 958 / PRO 958 (LU-205/LU-303): Signal: LUDB CN4-1 to 4, Location: LU-205/LU-303 3-G
- Observe whether the LCT’s internal transport rollers (visible through the LCT access door on the transport section) rotate when M3 is commanded. With the paper bridge open, you can also observe whether the bridge entry rollers receive drive from M3
- Inspect the LCT paper bridge alignment:
- The paper bridge between the LCT and the base machine must be correctly seated and locked at both ends — the LCT-side and the machine-side bracket. A bridge that is misaligned by even 1–2 mm causes paper to skew entering the machine, producing 17-20 even when M3 is running correctly
- Confirm the bridge locking lever(s) are fully engaged. On LU-205 and LU-303 units, the bridge has a locking tab that clicks into place against the base machine’s paper path entry frame — if this tab is not fully engaged, the bridge flexes during paper transport and causes misalignment misfeeds
- Check the bridge transport rollers for glazing — clean with a damp lint-free cloth
- Interpret:
- M3 runs and bridge rollers turn: M3 is functional. If 17-20 still occurs, check the bridge alignment (above) and then check M7 in the base machine (Step 8)
- M3 does not run: Check the M3 connector to LUDB CN4. Test M3 winding resistance. If M3 is open-circuit, replace M3. If M3 resistance is within spec but M3 does not run, check LUDB power supply and then replace LUDB (Step 10)
Step 8 — Check the Tray 2 Vertical Transport Motor (M7) and Sensor (PS12/PS19) in the Base Machine — Jam Code 17-20
When PS3 activates (paper left the LCT) and paper successfully crosses the bridge, but PS12 or PS19 (the base machine’s Tray 2 vertical transport sensor) does not activate, the fault is in the base machine’s Tray 2 vertical transport section — not in the LCT itself. This is a 17-20 companion failure that is actually a base machine fault, not an LCT fault.
- In Service Mode, navigate to the motor load check section
- Command M7 (Tray 2 vertical transport motor) to run using the model-specific check signal:
- C659 / C759 (PFTDB): Check code: 28, Multi code: 13, 14, 15, 16, Signal: PFTDB CN10-9 to 12, Location: 13-P
- 758 / 808 / 958 (PFTDB): Signal: PFTDB CN10-9 to 12, Location: 13-P
- C250i / C300i / C360i and 750i/800i/900i (BASEB — M23): Check code: 28, Multi code: 36, 39, 45, Signal: BASEB CN31E-5 to 8, Location: 23-K
- Also check the Tray 2 vertical transport sensor (PS12 or PS19) in the I/O check section to confirm the sensor itself is switching correctly when paper is manually fed past it:
- PFTDB models — PS12: PFTDB CN12-10 (ON), Location: 3-P
- BASEB models — PS19: BASEB CN23E-8 (ON), Location: 15-K
- Inspect the Tray 2 vertical transport roller inside the base machine’s right-side door for glazing — this is the same roller section that can cause 12-01 and 13-01, and it is also the roller that receives LCT paper from the paper bridge. A glazed transport roller causes 17-20 on LCT paper even when the 12-01 cassette tray path works acceptably on lighter copy paper
- If M7 does not run: check the PFTDB fuse (F11, F12, F13, or F15 on PFTDB models) for continuity before replacing M7 or the board. Check M7 connector seating and winding resistance
Step 9 — Check the Transfer LCT Vertical Transport Motor (M132 / M151) in Service Mode — Jam Code 16-01
For Jam Code 16-01 on internal LCT configurations (PC-410/PC-415/PC-416/PC-417), the feed motor (M131/M152) picked up the paper and activated PS132, but the vertical transport motor (M132/M151) that carries the sheet upward through the cabinet’s vertical transport section is not running or is failing to complete the transport stroke.
- In Service Mode, navigate to the motor load check section
- Command the LCT vertical transport motor to run:
- C458 / C558 / C658 / 458e / 558e / 658e (PC-415): Check code: 28, Multi code: 5, 6, 7, 8, Signal: PCCB CN5-9 to 16, Location: PC-415 4-J
- C250i / C300i / C360i (PC-417): M151 Check code: 28, Multi code: 56, 57, 58, 59, 60, Signal: PCCB CN20-1 to 3, Location: PC-417 7-K
- Observe the vertical transport roller inside the LCT cabinet section turning when the motor is commanded
- Also check the vertical transport sensor (PS133/PS153) by manually advancing a sheet of paper past the sensor — it should switch from OFF to ON. If PS133/PS153 is stuck ON from a paper fragment, clear the debris before replacing any components
- Check PCCB fuse IC2 (PC-415) or PCCB F4 (PC-417) for continuity if the motor does not respond — a blown protection component is the common cause when the motor previously stalled under paper load
- Inspect the internal LCT vertical transport roller for glazing or contamination — clean with a damp lint-free cloth. Also check the idle roller pressure springs inside the LCT transport section for spring fatigue, using the same procedure described in the 12-01 and 13-01 articles for the base machine’s vertical transport section
Step 10 — Replace the LUDB (LU Drive Board)
The LUDB is the control board inside the LCT housing that drives M2, M3, reads PS3, and communicates all LCT status and commands with the base machine. If sensor and motor checks confirm that individual components are functioning when tested in isolation but 15-01 or 17-20 still fires during powered LCT print cycles, the LUDB’s motor driver or sensor input circuits have failed.
- Power OFF and unplug the LCT and the base machine
- Access the LUDB inside the LCT housing — on LU-302 and LU-207 units the LUDB is mounted on the rear or right-side wall of the LCT housing, accessible after removing the LCT rear or side cover panel
- Before removing the LUDB, photograph or note all connector positions — the LUDB typically has 5–8 connectors including the motor drive connectors, sensor connectors, and the inter-unit harness connector
- Reseat all LUDB connectors one final time and power on to rule out a loose board connector before committing to board replacement
- If reseating does not resolve the issue, replace the LUDB with the correct part number for the specific LCT model installed:
- LU-302 LUDB — verify part number against the LCT model plate
- LU-207 LUDB — different part number from LU-302; confirm before ordering
- LU-205 / LU-303 LUDB — verify against the LCT model plate on the unit
- After installing the replacement LUDB, reconnect all harnesses, power on, perform the pickup roller load adjustment (Step 2), and run a 20-page LCT print test before leaving the site
ℹ️ PCCB fuse check before LUDB replacement: On base machines with a PCCB installed alongside the LCT (machines with PC-110/PC-210/PC-116/PC-216 cabinets also installed), the PCCB has fuses (F10 or F12) that protect the 24V supply going to the LCT’s LUDB. If the LUDB is not receiving 24V power, no motor will run and the sensor check will return no signal — this mimics a completely failed LUDB but is actually a blown PCCB fuse. Always test PCCB F10 and F12 continuity before replacing the LUDB on machines where both a PCCB and an LCT are installed.
Step 11 — Replace the Base Machine Control Board (Last Resort)
If the LUDB has been replaced, M2 and M3 are confirmed running correctly, PS3 switches correctly, the inter-unit harness is verified intact, and the issue persists, the fault is in the base machine control board’s ability to communicate with or power the LUDB.
- Replace MFPB — bizhub C258/C308/C368, C458/C558/C658, 458e/558e/658e, 368e/308e
- Replace BASEB — bizhub C250i/C300i/C360i, 750i/800i/900i
- Replace PFTDB, then MFPB — bizhub 758/808/958/PRO 958, C659/C759 (try PFTDB before MFPB for isolated LCT codes)
- Replace PCCB, then MFPB or BASEB — for Jam Code 16-01 on internal LCT (PC-415/PC-417) configurations, replace PCCB before the main base machine board
Quick Reference — Troubleshooting by Jam Code and Symptom
| Jam Code / Symptom | Most Likely Cause | First Action |
|---|---|---|
| 15-01 — paper does not move at all from LCT stack | Pickup roller load pressure too light; M2 not running; LUDB not powered | Perform pickup roller load adjustment (Step 2) first; then check M2 in service mode; check LUDB inter-unit harness and PCCB fuses |
| 15-01 — paper moves slightly but stops before reaching PS3 | LCT feed/pickup roller glazed; one-way clutch on feed roller shaft slipping (on models with one-way clutch) | Inspect pickup and feed roller surfaces; clean or replace as a set; recheck pickup roller load pressure after replacement |
| 15-01 — intermittent, occurs approximately 1 in 20–50 LCT pages | Pickup roller spring pressure borderline; roller beginning to glaze | Perform pickup roller load adjustment; clean pickup roller; monitor — if intermittent 15-01 persists after adjustment, replace roller set |
| 15-01 — appears immediately after LCT was moved or serviced | Inter-unit harness connector not fully reseated after LCT repositioning | Power OFF; locate and reseat inter-unit harness at both LCT and machine ends; reseat all LUDB connectors |
| 15-01 with PS3 stuck ON in service mode, no paper present | Paper fragment in PS3 beam slot; PS3 failed in blocked state | Inspect PS3 slot inside LCT for paper debris; clear any fragment; if slot is clear, replace PS3 |
| 15-01 with M2 not responding in service mode | LUDB not receiving 24V; blown PCCB fuse; failed M2 motor; failed LUDB | Check PCCB F10/F12 continuity; check M2 connector; test M2 winding resistance; replace LUDB if M2 is good and LUDB has power |
| 16-01 — internal LCT (PC-410/PC-415/PC-416/PC-417), PS132 activated but PS133 not activated | M132/M151 (LCT vertical transport motor) not running; internal VT roller glazed; PCCB fuse blown | Command M132/M151 in service mode; inspect internal VT roller; check PCCB IC2 or F4 fuse continuity |
| 16-05 — internal LCT (PC-410/PC-415), PS132 never activated | M131/M152 (LCT feed motor) not running; LCT pickup roller glazed or lift failed; PCCB communication lost | Check M131/M152 in service mode; inspect pickup roller; check inter-unit harness and PCCB power |
| 17-20 — PS3 activated, PS12/PS19 not activated, paper stopped on bridge | M3 (LCT transport motor) not running; bridge misaligned or not fully locked to base machine | Command M3 in service mode; inspect bridge alignment and locking mechanism; clean bridge transport rollers |
| 17-20 — PS3 activated, paper crossed bridge, stopped in base machine Tray 2 VT section | M7 (base machine Tray 2 VT motor) not running; Tray 2 VT roller glazed; PFTDB fuse blown | Command M7 in service mode; inspect Tray 2 VT roller inside base machine; check PFTDB fuses F11–F15 |
| Double-feed from LCT (multiple sheets feeding simultaneously) leading to jams | LCT separation roller/retard pad worn; pickup roller load pressure set too high | Replace LCT separation roller/retard pad; check and reduce pickup roller load pressure to within specification |
| 15-01 on heavy paper from LCT only — standard 80 g/m² feeds fine | Pickup roller spring pressure too low for heavier stock weight; or feed roller glazed | Increase pickup roller load pressure within specification; clean feed roller; if still insufficient, replace roller set |
| LCT produces 15-01 only from a full stack (3,000 sheets), works fine at half-stack | Pickup roller spring pressure correct at mid-stack but too low when elevator is at full-stack height — spring arm angle geometry issue | Recheck pickup roller load adjustment with a full stack, not just at mid-stack; adjust spring to compensate for full-stack geometry |
Understanding the Full LCT Jam Code Family
LCT jam codes form a logical sequence from the pickup roller through to the main paper path. Understanding the complete family prevents misidentifying which zone failed:
- 15-01 — LCT primary feed misfeed — PS3 not activated. Paper did not leave the LCT feed section within the allowed time. The fault is inside the LCT: pickup roller, M2, PS3, LUDB, or inter-unit harness. This is the primary LCT no-feed code. This article
- 15-40 — LCT image write signal timeout. The paper path is delivering paper but the image write signal synchronization has failed. More often a board-timing or LUDB-to-base-machine communication fault than a mechanical paper path issue
- 16-01 — Transfer LCT (internal PC-410/PC-415/PC-416/PC-417 LCT) feed/transport misfeed — PS132 activated but PS133 not activated. Paper left the feed nip but stalled in the internal LCT’s vertical transport section. Fault is M132/M151 or the internal VT roller. Covered in this article
- 16-05 — Transfer LCT primary feed misfeed — PS132 never activated. Paper did not leave the feed nip at all. Fault is M131/M152 or the pickup roller inside the internal LCT. Sub-code of the 16-01 family
- 16-40 — Transfer LCT image write signal timeout. Same logic as 15-40 but for the internal LCT
- 17-20 — LCT transport section misfeed — PS3 activated but PS12/PS19 not activated. Paper successfully left the LCT but did not reach the base machine’s Tray 2 vertical transport sensor. Fault is M3 (LCT transport motor), paper bridge alignment, or M7 (base machine Tray 2 VT motor). Covered in this article
- 20-01 — Main machine vertical transport misfeed — PS38 (registration sensor) not activated after PS4 (Tray 1 VT sensor). On 758/808/958/C659/C759 machines, LCT paper that clears the 17-20 detection zone and enters the main transport path can still produce 20-01 if the main registration motor (M2) or main transport motor (M30) fails. When 17-20 and 20-01 appear together, the LCT delivered paper to the base machine but the base machine’s own transport failed to carry it to the registration sensor
- C0501–C0507 — LCT lift motor abnormality codes — the LCT paper lift elevator motor (the motor that raises the large paper stack to the pickup height) is not operating within the allowed timing or speed parameters. When C0501–C0507 accompany 15-01, the paper stack is not being presented at the correct height to the pickup roller — the lift fault must be resolved before addressing the 15-01 feed failure
Preventing LCT Jams From Recurring
- Perform the LCT pickup roller load adjustment at every PM visit — without exception. This is the single highest-impact preventive action for LCT jam codes. The pickup roller spring weakens gradually over high-volume use and must be checked and readjusted at every PM. On high-volume LCT installations (above 10,000 LCT copies per month), consider checking the load adjustment every 100,000 LCT copies, not only at the standard PM interval
- Include the LCT roller set in every PM kit for high-volume LCT installations. Standard PM kits for the base machine do not always include LCT roller components. On installations where the LCT is the primary paper source (many high-volume document printing environments), the LCT pickup, feed, and separation rollers can reach end-of-life before the next PM cycle. Track LCT-specific copy counts separately from base machine counts and replace LCT rollers on their own schedule where usage data supports this
- Inspect and reseat the LCT inter-unit harness at every PM that involves opening the LCT or moving the unit. The inter-unit harness connector between the LCT and the base machine is handled every time the LCT paper path bridge is removed or the LCT is repositioned. Reseat the connector and inspect for bent pins as a standard PM step. This 60-second check prevents the most common post-PM LCT callback call
- Clean the paper bridge transport rollers at every PM. The paper bridge between the LCT and the base machine accumulates paper dust and debris faster than internal machine rollers because it is exposed to room environment through the bridge opening. A 60-second cleaning of the bridge rollers with a damp cloth at each PM prevents bridge transport roller glazing from causing 17-20 codes between PM intervals
- Check bridge alignment and locking at every PM. On LU-205 and LU-303 units especially, the paper bridge can shift slightly from machine vibration over time. Confirm the bridge is firmly locked at both the LCT-side and machine-side brackets, and check for any visible gap between the bridge and the machine paper path entry. A 2 mm bridge gap causes paper leading edges to buckle at entry, producing 17-20 and crumpled-paper jams
- Load LCT paper correctly — fan the stack and do not overfill. LCT paper that has been sitting in the unit for extended periods should be fanned before the PM visit to separate any sheets that have stuck together from humidity or compression. Overfilling the LCT above the maximum fill mark compresses the top of the stack and reduces the effective pickup roller pressure on the topmost sheets. Advise customers to load LCT paper in 500-sheet increments rather than in a single full load
- Run a 20-page LCT print test after every PM before leaving the site. Marginal pickup roller pressure that fails on page 15 but not page 1 will not be caught by a brief 3-page post-PM test. A 20-page run from the LCT after every PM specifically catches borderline pressure issues before the customer encounters them
Professional Technician Summary
LCT jam codes 15-01, 16-01, and 17-20 on Konica Minolta bizhub machines cover paper feed failures across three distinct zones of the LCT-to-base-machine paper path, and the key to efficient diagnosis is reading the jam code accurately before touching any component — the code tells you exactly which zone failed.
15-01 means paper never left the LCT — the fault is inside the LCT unit itself. In the field, the dominant cause of 15-01 is incorrect pickup roller spring pressure, followed closely by pickup roller or feed roller glazing. The service manual explicitly lists “Make the pick-up roller load adjustment of the LCT” as the mandatory second step before any electrical check — this is field-validated guidance that the adjustment is the most common non-electrical root cause. Always perform the load adjustment before entering service mode on a 15-01 call.
16-01 means paper left the feed nip but stalled in the internal LCT’s vertical transport section. On PC-410/PC-415 configurations, M132 (LCT vertical transport motor) failure or a glazed internal VT roller is the primary cause. Check the PCCB protection fuse (IC2 on PC-415, F4 on PC-417) before replacing the motor or the board — an overloaded or jammed motor will blow the fuse without damaging the board, and replacing a board for a blown fuse is a significant unnecessary cost.
17-20 means paper left the LCT successfully but stalled between the LCT exit and the base machine’s Tray 2 VT sensor. The two most common causes are M3 (LCT transport motor) failure and paper bridge misalignment. On units where the bridge has been recently removed and reinstalled, always check bridge alignment and locking before running a motor check in service mode — a misaligned bridge is a zero-cost fix that takes 30 seconds.
In all three cases, the inter-unit harness between the LCT and the base machine should be the first physical check when the fault appears immediately after any service that involved the LCT or the paper bridge. A connector not fully seated after PM is the leading cause of post-PM LCT callback calls across all LCT models and all base machine platforms.