• Code: C280
• Description: Carriage home position sensor not going ON within a specified time
• Causes: Home position sensor SLG board
• Remedy: dure Check item Result Measure Next Step 1 Do the carriages make a big noise after they arrive at the home position? Yes 2 No 3 2 Home position sensor SLG board The carriage home position sensor is not turned ON. • Check if the connector of the sensor is disconnected. • Check if the circuits of the SLG board are abnormal. 3 SLG board The carriages are stopped at the home position and do not move. • Check if the connector pins are disconnected or the harnesses are short circuited or open circuited. • Check if the conductor pattern on the SLG board is short circuited or open circuited.

• Code: C290
• Description: Scanner fuse blowout. The scanning system does not operate due to a blowout of the fuse in the scanning system.
• Causes: Fuse in the scanning system SLG board
• Remedy: 1 Power supply unit Check if any fuse in the scanning system is blown out. 2 SLG board Check if the conductor pattern on the SLG board is short circuited or open circuited. Check if the 24V output and the grounding wire are normal.

• Code: C370
• Description: Transfer belt motor abnormality
• Causes: Transfer belt motor LGC board
• Remedy: Transfer belt unit • Connector check (J578) • Check if the transport belt unit is working normally. Transfer belt motor Connector check LGC board Connector check (CN332) Transfer belt Check if it’s normal Release detection sensor Sensor check

• Code: C380
• Description: Auto-toner sensor-K abnormality (upper 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 developer material is too dark visually. • Check if the amount of the developer material is too large or too small. 2 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. 3 Auto toner sensor - Equipment Harness - LGC board • Check the connectors and harnesses between the auto toner sensor and LGC board (CN340). • Remove any foreign matter such as toner in the connector of the auto toner sensor.

• Code: C381
• Description: Auto-toner sensor-K 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 developer material is too light visually. • Check if the amount of the developer material is too large or too small. 2 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. 3 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: C390
• Description: Auto-toner sensor-C 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: C391
• Description: Auto-toner sensor-C 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: C3A0
• Description: Auto-toner sensor-M 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.