• Code: 491
• Description: High voltage power: Drum/ development bias output error
  An error signal is detected for 0.2 seconds when charging the drum or development.
• Causes: • High voltage leak • Broken harness • Defective drum unit or development unit • Defective high voltage supply unit
• Remedy: 1. Check or replace the harness. 2. Replace the drum unit or paper transfer unit. 3. Replace the high voltage supply unit.

• Code: 492
• Description: High voltage power: Image transfer/ paper transfer bias output error
  An error signal is detected for 0.2 seconds when charging the separation, image transfer bet or paper transfer roller.
• Causes: • High voltage leak • Broken harness • Defective image transfer belt unit or paper transfer unit • Defective high voltage supply unit
• Remedy: 1. Check or replace the harness. 2. Replace the image transfer belt unit or paper transfer unit. 3. Replace the high voltage supply unit.

• Code: 498
• Description: Temperature and humidity sensor error
  • The thermistor output of the temperature sensor is not within the prescribed range (0.5V to 4.2V). If this is detected consecutively three times, the SC is generated and the machine defines that the temperature is "23°C". • The thermistor output of the humidity sensor is not within the prescribed range (0.01V to 2.4V). If this is detected consecutively three times, the SC is generated and the machine detects that the humidity is "50%".
• Causes: • Temperature and humidity sensor harness disconnected, loose, defective • Temperature and humidity sensor defective
• Remedy: 1. Check the connector and harness. 2. Replace the temperature/humidity sensor.

• Code: 501
• Description: Paper Tray 1 error
  • When the tray lift motor rotates counterclockwise, (if the upper limit is not detected within 10 seconds), the machine asks the user to reset the tray. • When the tray lift motor rotates clockwise, (if the upper limit is not detected within 1.5 seconds), the machine asks the user to reset the tray. If one of these conditions occurs three consecutive times, the SC is generated.
• Causes: • Disconnected or defective paper lift sensor • Disconnected or defective tray lift motor • Defective bottom plate lift mechanism • Too much paper in the tray • Defective IOB
• Remedy: 1. Check if the paper is not loaded too much. 2. Check if the bottom plate smoothly moves up and down manually. 3. Check and/or replace the tray lift motor. 4. Replace the IOB.

• Code: 502
• Description: Paper Tray 2 error
  • When the tray lift motor rotates counterclockwise, (if the upper limit is not detected within 10 seconds), the machine asks the user to reset the tray. • When the tray lift motor rotates clockwise, (if the upper limit is not detected within 1.5 seconds), the machine asks the user to reset the tray. If one of these conditions occurs three consecutive times, the SC is generated.
• Causes: • Disconnected or defective paper lift sensor • Disconnected or defective tray lift motor • Defective bottom plate lift mechanism • Too much paper in the tray • Defective IOB
• Remedy: 1. Check if the paper is not loaded too much. 2. Check if the bottom plate smoothly moves up and down manually. 3. Check and/or replace the tray lift motor. 4. Replace the IOB.

• Code: 503-01
• Description: Tray 3 error (Paper Tray Unit, Paper Feed Unit or LCT)
  For the two-tray paper feed unit or one-tray paper tray unit: • When the tray lift motor is turned on, the upper limit is not detected within 10 seconds For the LCT: • SC 503-01 occurs if the upper or lower limit is not detected within 8 seconds when the tray lift motor is turned on to lift or lower the tray.
• Causes: For the two-tray paper feed unit or one-tray paper tray unit: • Defective tray lift motor or connector disconnection • Defective lift sensor or connector disconnection For the LCT: • Defective stack transport clutch or connector disconnection • Defective tray motor or connector disconnection • Defective end fence home position sensor or connector disconnection • Defective upper limit sensor or connector disconnection • Defective tray lift motor or connector disconnection
• Remedy: 1. Check the cable connections. 2. Check and/or replace the defective component.

• Code: 503-02
• Description: Tray 3 error (Paper Tray Unit, Paper Feed Unit or LCT)
  This SC is generated if the following condition occurs 3 consecutive times. For the two-tray paper feed unit or one-tray paper tray unit: • When the tray lowers, the tray lift sensor does not go off within 1.5 sec. For the LCT: • When the main switch is turned on or when the LCT is set, if the end fence is not in the home position (home position sensor ON), the tray lift motor stops. • If the upper limit does not go off for 1.5 seconds even the tray lift motor turns on to lower the tray after the upper limit has been detected at power on.
• Causes: For the two-tray paper feed unit or one-tray paper tray unit: • Defective tray lift motor or connector disconnection • Defective lift sensor or connector disconnection For the LCT: • Defective stack transport clutch or connector disconnection • Defective tray motor or connector disconnection • Defective end fence home position sensor or connector disconnection
• Remedy: 1. Check the cable connections. 2. Check and/or replace the defective component.

• Code: 504-01
• Description: Tray 4 error (Paper Tray Unit, Paper Feed Unit or LCT)
  For the two-tray paper feed unit or one-tray paper tray unit When the tray lift motor is turned on, the upper limit is not detected within 10 seconds. For the LCT If the upper or lower limit is not detected within 8 seconds when the tray lift motor is turned on to lift up or lower the tray
• Causes: • Defective tray lift motor or connector disconnection • Defective lift sensor or connector disconnection
• Remedy: 1. Check the cable connections. 2. Check and/or replace the defective component.