• Code: A1
• Description: Uninstalled waste toner conveyer
  The waste toner conveyer is not installed, or the conveyer is clogged inside with waste toner.
• Causes: • Waste toner converyer is not installed. • The belt is not rotating in the conveyer unit. • Connection failure between the CON1 board and the conveyer board • Engine gate arrays (U2/U6) failure • Defective LED driving circuit on the engine board. Defective LED on the conveyer board. Connection failure between the waste toner conveyer board and the photo transistor. Defective photo transistor. • Contaminated waste toner conveyer housing or photo receptor. • The waste toner driving system in the toner container is not working properly.

• Code: A2
• Description: Fuser overheating
  The fuser unit is overheating.
• Causes: • Defective photo-coupler (low voltage) for heaters • Defective engine gate array U2 • Defective heater control circuit (engine board) or heater temperature detector

• Code: A3
• Description: Fuser heater disconnection
  Either or both heater lamp(s) is blown out.
• Causes: • Blown-out heater lamp(s) • Defective connection between the engine board and the low voltage supply. • Malfunctioning engine CPU • Defective heater disconnection sensor circuit in the low voltage supply • Defective thermo-cut (Replace the fuser unit.)

• Code: A4
• Description: Developer unit life-fuse error
  The life fuse won’t cut in the developer unit.
• Causes: • Defective engine gate array • Defective fuse cut circuit on the engine board

• Code: B1 ... B6
• Description: Feed cassette bottom plate motor error
  The feed cassette bottom plate motor won’t revolve.
• Causes: • Excessive torque on the motor (activating the current protection circuit) • Stuck motor • Defective feed board PU (U1) • Defective motor driver circuit (transistors) or over-current detector circuit

• Code: C1
• Description: Duplex communication error
  Communication error between the duplexer and the printer.
• Causes: • Defective engine gate array (U6) • Defective engine CPU (U1) • Duplexer CPU (U1) malfunction • Defective U2, U5, U6 on duplexer board • Defective connection between KP-544 (YC4) and KP-568 (YC1), KP-568 (YC3) and liaison connector, liaison connector and KP-587 (YC1), or defective liaison connector

• Code: C2
• Description: Duplex printing registration error
  The duplexer’s registration boards are not in the home position.
• Causes: • Defective registration motor • Defective home position sensor • Malfunctioning motor driving circuit (U2/U6/U7) on duplexer board • Defective duplxer CPU (U1) • Connection error between the registration motor and KP-587 (YC5), or home position sensor and KP-587 (YC7)

• Code: C4
• Description: DF-30 IPC communication error
  Communication error with the document finisher DF-30
• Causes: • Defective IPC (intelligent protocol controller) LSI (communication chip) • Defective interface connector/cable