• Code: 3500
• Description: Communication error between scanner and ASIC An error code is detected.
• Causes: CIS. Main/Engine PWB.
• Remedy: CIS 1. Execute U906 Separating Operation Release. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. CIS and main/engine PWB (YC2011) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the CIS and execute U411.
  Main/Engine PWB Replace the main/engine PWB and check for correct operation.

• Code: 3600
• Description: Scanner sequence error
• Causes: Main/Engine PWB.
• Remedy: 1. Execute U021 memory initializing. 2. Replace the main/engine PWB and execute U411.

• Code: 4000
• Description: Polygon motor steady-state error
  After Polygon motor is stabilized, the ready signal is at the H level for 1 s continuously.
• Causes: Polygon motor (LSU). Main/Engine PWB.
• Remedy: Polygon motor (LSU) 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Polygon motor and main/engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the laser scanner unit.
  Main/Engine PWB 1. Check the main/engine software and upgrade to the latest, if necessary. 2. Replace the main/engine PWB.

• Code: 4010
• Description: Polygon motor synchronization error
  After polygon motor is driven, the polygon motor speed won’t stabilize within 10 s.
• Causes: Polygon motor (LSU). Main/Engine PWB.
• Remedy: Polygon motor (LSU) 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Polygon motor and main/engine PWB (YC10) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the laser scanner unit.
  Main/Engine PWB 1. Check the main/engine software and upgrade to the latest, if necessary. 2. Replace the main/engine PWB.

• Code: 4200
• Description: BD steady-state error
  The BD signal is not detected.
• Causes: APC PWB (LSU). Main/Engine PWB.
• Remedy: APC PWB (LSU) 1. Confirm that the FCC wiring connector is not distorted and connect the FCC wiring all the way in. Laser scanner unit and main/engine PWB (YC2010) 2. If the FCC wiring is disconnected, shorted or grounded, replace the FCC wiring. 3. Replace the laser scanner unit.
  Main/Engine PWB 1. Check the main/engine software and upgrade to the latest, if necessary. 2. Replace the main/engine PWB.

• Code: 6000
• Description: Broken fuser heater wire (main)
  When the fuser thermistor 1 reaches primary stable temperature after a warm-up start and the fuser thermistor 2 is less than 90 ° C/194 °F.
• Causes: Fuser unit. Main/Engine PWB. Power source PWB. Fuser heater.
• Remedy: Fuser unit 1. Check that no paper jam is present. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Fuser unit and mmain/engine PWB (YC14) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the Fuser unit and execute U167 counter clear. (Deteriorated sensitivity due to the toner adhered to the center thermistor.)
  Main/Engine PWB 1. Check the main/engine software and upgrade to the latest, if necessary. 2. Replace the main/engine PWB.
  Power source PWB 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Power source PWB (YC4) and main/ engine PWB (YC14) 2. Replace the power source PWB.
  Fuser heater 1. Replace the Fuser unit and execute U167 counter clear.

• Code: 6020
• Description: Abnormally high fuser thermistor 2 temperature (Center)
  Fuser thermistor 2 detects a temperature higher than 210°C/410°F.
• Causes: Fuser unit. Main/Engine PWB.
• Remedy: Fuser unit 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Fuser unit and main/engine PWB (YC14) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Fuser unit.
  Main/Engine PWB 1. Check the main/engine software and upgrade to the latest, if necessary. 2. Replace the main/engine PWB.

• Code: 6030
• Description: Broken fuser thermistor 2 wire (Center)
  Input from fuser thermistor 2 is 1012 or more (A/D value) continuously for 5 s. Input from fuser thermistor 2 is1012 (A/D value) or more whenthe temperature at the fuser thermistor 1 is 70°C/ 158°F or more.
• Causes: Fuser unit. Main/Engine PWB. Fuser thermistor 2. Fuser thermostat (triggered)
• Remedy: Fuser unit 1. Check that no paper jam is present. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Fuser unit and main/engine PWB (YC14) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the Fuser unit and execute U167 counter clear. (Deteriorated sensitivity due to the toner adhered to the center thermistor.)
  Main/Engine PWB 1. Check the main/engine software and upgrade to the latest, if necessary. 2. Replace the main/engine PWB.
  Fuser thermistor 2 1. Replace the Fuser unit and execute U167 counter clear.
  Fuser thermostat (triggered) 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Fuser unit and fuser heater PWB (YC1) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the Fuser unit and execute U167 counter clear.