• Code: C390
• Description: Auto-toner sensor-C abnormality (upper limit)
• Causes: Auto toner sensor Harness LGC board Developer material High-voltage transformer
• Remedy: 1 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. • Remove any toner or dust on the auto-toner 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. 2 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN313, J633, J634). • 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: C391
• Description: Auto-toner sensor-C abnormality (lower limit)
• Causes: Auto toner sensor Harness LGC board Developer material
• Remedy: 1 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 amount of the developer material is too large or too small. • Remove any toner or dust on the auto-toner 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. 2 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN313, J633, J634). • 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: C3A0
• Description: Auto-toner sensor-M abnormality (upper limit)
• Causes: Auto toner sensor Harness LGC board Developer material High-voltage transformer
• Remedy: 1 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. • Remove any toner or dust on the auto-toner 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. 2 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN313, J631, J632). • 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: C3A1
• Description: Auto-toner sensor-M abnormality (lower limit)
• Causes: Auto toner sensor Harness LGC board Developer material
• Remedy: 1 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 amount of the developer material is too large or too small. • Remove any toner or dust on the auto-toner 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. 2 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN313, J631, J632). • 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 High-voltage transformer
• Remedy: 1 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. • Remove any toner or dust on the auto-toner 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. 2 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN313, J629, J630). • 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 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 amount of the developer material is too large or too small. • Remove any toner or dust on the auto-toner 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. 2 Auto toner sensor Harness LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN313, J629, J630). • 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: C3E1
• Description: Drum/cleaner/charger unit replacement (old-new) detection abnormality
• Causes: Drum old/new detection switches Drum TBU motor LGC board Harness
• Remedy: 1 Check if the old/new detection pusher of the drum cleaner unit is being ejected. Yes 4 No 2 2 Check if the harness of the drum old/new detection switch in the drum cleaner unit is open circuited. Yes 3 No Replace the harness. 3 Is the drum old/new detection switch of the drum cleaner unit normal? Yes 4 No Replace the drum old/new detection switch. 4 Check if the drum old/new detection pusher is moved to the escape position while the coupling of the drum cleaner unit is rotated by hand. (Is a driving in the old/new detection pusher section transmitted?) Yes 3 No Correct the drum old/new detection pusher so that it is moved to the escape position. 5 Check that the coupling of the drum TBU drive unit is driven properly. Yes Correct the engagement of the couplings in the drum TBU drive unit and the drum cleaner unit. 9 No 6 6 Check that the drum TBU drive motor rotates properly. (Input check: FS-03-101/151) Yes 9 No 7 7 Check that the connector of the drum TBU drive motor is connected properly. (CN327, J651) Yes 9 No 8 8 Check if the harness of the drum TBU drive motor is open circuited. Yes 9 No Replace the drum TBU drive motor. 9 Check that the connector of the LGC board (CN313, CN327) is connected properly. Yes 11 No Reconnect the connector. 10 Is the harness of the LGC board normal? Yes 11 No Replace the harness. 11 Is the LGC board normal? Replace the LGC board.

• Code: C445, C446
• Description: Heater temperature abnormality after abnormality judgment
• Causes:
• Remedy: 1 Power voltage Check if the power voltage is normal.(Is the voltage during the operation ±10% of the rated voltage?) 2 Thermistor • Check if the center and edge thermistor are installed properly. • Check if the harnesses of the center and edge thermistor are open circuited. • Check if the connectors of the center and edge thermistor are disconnected (CN306, J608). 3 Switching regulator and fuser unit • Is the fuser unit installed correctly? • Check if the IH-COIL is broken. • Check if the terminal of the IH-COIL is attached securely. • Check if the thermostat is blown • Check if the drawer connector is damaged or its connection is detected. • Check if the connectors of the power supply unit are disconnected (CN504, CN505, CN56, CN564, CN565). • Check if the power supply unit is abnormal. 4 LGC board • Check if the connectors CN306 and CN302 are disconnected. • Check if the conductor pattern on the LGC board is short circuited or open circuited. 5 Clear the status counter 1. Perform FS-08-2002. 2. Change the current status counter value "5", "6", "7", "9", "10", "22", "23", "24", "25", "27", "29", or "63 to 70". * The status counter value is as follows in the following cases. - The error occurred during warming-up: "5" or "6" The error occurred after the equipment has become ready: "7". - The temperature detected by the center thermistor is 220°C or higher, the temperature detected by the edge thermistor is 237°C or higher: "9", "10", "22", "23", "25", "27" or "29" - The error occurred during printing: "24", "25", or "64 to 70". - The error occurred during energy saving: "27". - A paper jam occurred: "29".