• Code: C3A1
• Description: Auto-toner sensor-M abnormality (lower limit)
• Causes: Auto toner sensor Harness LGC board Developer material
• Remedy: 1 <Color toner low density> Check the printing status. Is the color printing ratio 5% or more? Yes 2 No The color toner low density might be the cause. Turn the code 08-2692 "Prevention of color toner low density / ON/OFF setting" to ON, and then set number of sheets to be judged at the code 08- 2693 "Prevention of color toner low density/Judged number of sheets setting". 2 Developer unit • Check if the developer unit is installed properly. • Check that the developer unit and coupling on the equipment side are properly engaged. • Check that the mixer of the developer unit is rotated. • Check if the developer material is too light visually. • Check if the amount of the developer material is too large or too small. 3 EPU • Remove any toner or dust on the ATC sensor connector and the drawer connector of the process cover. • Remove any toner or dust on the EPU sensor connector and the drawer connector on the equipment side. 4 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN340). • Check if there is any foreign matter such as toner in the connector of the auto toner sensor. Remove if there is and reconnect it.

• Code: C3B0
• Description: Auto-toner sensor-Y abnormality (upper limit)
• Causes: Auto toner sensor Harness LGC board Developer material
• Remedy: 1 <Color toner low density> Check the printing status. Is the color printing ratio 5% or more? Yes 2 No The color toner low density might be the cause. Turn the code 08-2692 "Prevention of color toner low density / ON/OFF setting" to ON, and then set number of sheets to be judged at the code 08- 2693 "Prevention of color toner low density/Judged number of sheets setting". 2 Developer unit • Check if the developer unit is installed properly. • Check that the developer unit and coupling on the equipment side are properly engaged. • Check that the mixer of the developer unit is rotated. • Check if the developer material is too dark visually. • Check if the amount of the developer material is too large or too small. 3 EPU • Remove any toner or dust on the ATC sensor connector and the drawer connector of the process cover. • Remove any toner or dust on the EPU sensor connector and the drawer connector on the equipment side. 4 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN340). • Check if there is any foreign matter such as toner in the connector of the auto toner sensor. Remove if there is and reconnect it.

• Code: C3B1
• Description: Auto-toner sensor-Y abnormality (lower limit)
• Causes: Auto toner sensor Harness LGC board Developer material
• Remedy: 1 <Color toner low density> Check the printing status. Is the color printing ratio 5% or more? Yes 2 No The color toner low density might be the cause. Turn the code 08-2692 "Prevention of color toner low density / ON/OFF setting" to ON, and then set number of sheets to be judged at the code 08- 2693 "Prevention of color toner low density/Judged number of sheets setting". 2 Developer unit • Check if the developer unit is installed properly. • Check that the developer unit and coupling on the equipment side are properly engaged. • Check that the mixer of the developer unit is rotated. • Check if the developer material is too light visually. • Check if the amount of the developer material is too large or too small. 3 EPU • Remove any toner or dust on the ATC sensor connector and the drawer connector of the process cover. • Remove any toner or dust on the EPU sensor connector and the drawer connector on the equipment side. 4 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN340). • Check if there is any foreign matter such as toner in the connector of the auto toner sensor. Remove if there is and reconnect it.

• Code: C411, C412
• Description: Thermistor / heater lamp abnormality at power-ON
• Causes: Power supply unit. LGC board
• Remedy: Power voltage Check if the power voltage is normal.(Is the voltage during the operation ±10% of the rated voltage?) Thermopiles • Check if the fuser belt center and side thermopiles (front, rear) are installed properly. • Check if the harnesses of the fuser belt center and side thermopiles (front, rear) are open circuited. Power supply unit and fuser unit • Is the fuser unit installed correctly? • Check if the heater lamp is broken. • Check if the connector of the heater lamp is disconnected. • Check if the thermostat is blown • Check if the connectors of the power supply unit are disconnected (power supply unit AC output connector CN408, CN409 and LGC I/F connector CN404 CN405). • Check if the power supply unit is abnormal. LGC board • Check if the connectors CN333, CN345 and CN361 are disconnected. • Check if the conductor pattern on the LGC board is short circuited or open circuited. Status counter After repairing the matter which caused the error [C411/C412], perform the following: • Turn ON the power while [0] and [8] are pressed simultaneously • Key in “2002”, then press [START]. • Change the current status counter value “1 “ or “2 “ to “0”, then press [OK] or [INTERRUPT] (to cancel [C411/C412]). • Turn the power OFF and then back ON. Make sure that the equipment enters the normal ready state.

• Code: C443, C445, C446
• Description: Heater lamp abnormality after abnormality judgment
• Causes: Power supply unit. LGC board
• Remedy: 1,2,3,4. Check the thermopiles, Heater and LGC board Check the above components following the procedures 1, 2,3 and 4 for [C411/C412].
  5 Clear the status counter Change the current status counter value (08-2002) “3”, “5”, “6”, “9”, “19”, “21”, “22”, “23”, “24”, “25”, “27”, “29” or “32” to “0” for [C44X], taking the same procedure as that for [C41X]. * The status counter value is as follows in the following cases. - The error occurred during warming-up: “3”, “5” or “6” The error occurred after the equipment has become ready: “7”. - The temperature detected by the fuser belt center thermopile is 220°C or higher, the temperature detected by the side thermopile is 230°C or higher or the temperature detected by the front thermopile is 250°C or higher: “9”, “19”, “21”, “22”, “23”, “25”, “27” or “29” - The error occurred during printing: “24” or “25”. - The error occurred during energy saving: “27”. - A paper jam occurred: “29”.

• Code: C447, C449
• Description: Heater lamp abnormality after abnormality judgment
• Causes: Power supply unit. LGC board
• Remedy: 1,2,3,4. Check the thermopiles, Heater and LGC board Check the above components following the procedures 1, 2,3 and 4 for [C411/C412].
  5 Clear the status counter Change the current status counter value (08-2002) “3”, “5”, “6”, “9”, “19”, “21”, “22”, “23”, “24”, “25”, “27”, “29” or “32” to “0” for [C44X], taking the same procedure as that for [C41X]. * The status counter value is as follows in the following cases. - The error occurred during warming-up: “3”, “5” or “6” The error occurred after the equipment has become ready: “7”. - The temperature detected by the fuser belt center thermopile is 220°C or higher, the temperature detected by the side thermopile is 230°C or higher or the temperature detected by the front thermopile is 250°C or higher: “9”, “19”, “21”, “22”, “23”, “25”, “27” or “29” - The error occurred during printing: “24” or “25”. - The error occurred during energy saving: “27”. - A paper jam occurred: “29”.

• Code: C448
• Description: Heater lamp lights continuously for a certain period of time when the pressure roller temperature during ready status is higher than the specified
• Causes: Power supply unit. LGC board
• Remedy: Power supply and fuser unit • Check if the fuser unit is installed properly • Check if foreign matter or paper in the fuser unit is plugging up the monitoring opening of the fuser belt thermopile. • Check if there is any stain on sensor area of the fuser belt thermopile. • Check if the opening of the fuser belt thermopile of the equipment is plugged up. • Check if the connectors of the power supply are disconnected (CN404, CN405, CN408, CN409). • Check if the power supply unit is abnormal. LGC board • Check if the connector CN333 is disconnected. • Check if the conductor pattern on the LGC board is short circuited or open circuited. Status counter After repairing the matter which caused the error [C448], perform the following: 1. Turn the power ON while [0] and [8] are pressed simultaneously. 2. Key in “2002”, then press the [START] button. 3. Change the displayed current status counter value “32” to “0”, then press [OK] or [INTERRUPT] (to cancel C448). 4. Turn the power OFF and then back ON. Make sure that the equipment enters the normal status.

• Code: C450 ... C452
• Description: [C450/C451] Abnormal temperature difference between the center thermopile and the edge thermistor [C452] Abnormal thermopile temperature diffe
• Causes: Power supply unit Thermopile LGC board
• Remedy: Power supply and fuser unit • Check if the fuser unit is installed properly. • Check if foreign matter or paper in the fuser unit is plugging up the monitoring opening of the thermopile. • Check if there is any stain on sensor area of the fuser belt thermopile. • Check if the heater lamp is open circuited. • Check if the connector of the heater lamp is disconnected. • Check if the thermistor is open circuited. • Check if the connectors of the power supply unit (power supply unit AC output connector CN408, CN409 and LGC/IF connector CN404, CN405) are disconnected. • Check if the power supply unit is broken. Thermopile • Check if foreign matter is plugging up the thermopile. • Check if the thermopile is installed properly. • Check if the harnesses are open circuited. LGC board • Check if the connectors CN333, CN345 and CN361 are disconnected. • Check if the conductor pattern on the LGC board is short circuited or open circuited. Status counter 1. Turn the power ON while [0] and [8] are pressed simultaneously. 2. Key in “2002”, then press the [START] button. 3. Reset the displayed current status counter value "38", "39", "41", "42", "48", "49", "50" or "51" to "0", then press [OK] or [INTERRUPT]. (The error C451 or C452 is cleared.) 4. Turn the power OFF and then back ON. Make sure that the equipment enters the normal status.