• Code: SC504
• Description: 4th paper tray error - Timing & Condition - • The upper limit sensor stays HIGH when the pick-up solenoid turns off. • The upper limit sensor stays LOW 1.5 seconds after the tray bottom plate goes down. • The upper limit sensor stays HIGH 10 seconds after the tray bottom plate goes up. • The upper limit sensor stays HIGH 3 seconds after the tray bottom plate goes up again.
• Causes: • Pick-up solenoid spring come off • Defective upper limit sensor • Defective tray bottom plate • Defective tray lift motor • Defective I/O control board • Defective main control board
• Remedy: 1. Check if the spring of pick-up solenoid comes off. 2. Check if the sensor harness is properly connected. 3. Clean or replace the sensor and replace it if necessary (Input Check: SP 5-803-014 to 017). 4. Replace the tray bottom lever if it is broken. 5. Pull out the paper tray and check if the tray lift motor works properly (Output Check: SP 5-804-75 to 82) 6. Replace the I/O control board. 7. Replace the main control board. [ Signal Check ] • Limit sensor H.P.: CN224-A8 or TP215 on I/O control board [ Signal Check ] • Limit sensor H.P.: CN226-B8 or TP280 on I/O control board

• Code: SC505
• Description: LCT: Upper limit detection error - Timing & Condition - • While the paper tray is being lifted, the upper limit sensor does not activate within 2.5 seconds after the paper end sensor activates.
• Causes: • Poor connection of the connectors • Defective paper end sensor • Paper is not properly loaded in the LCT or curled.
• Remedy: 1. Open the LCT cover and reload paper properly. 2. Check if the paper end sensor is properly connected. 3. Replace the paper end sensor.

• Code: SC510
• Description: Paper feed motor error - Timing & Condition - • The feedback signal from the motor is still out of range 1 second after the trigger signal is sent. • The feedback signal becomes out of range for 2 seconds while the trigger signal is ON.
• Causes: • Poor connection of connector • Defective paper feed motor • Defective I/O control board • Defective main control board • Mechanical overload
• Remedy: 1. Check if the connector is properly connected on the I/O control board (CN230). 2. Replace the paper feed motor. (Output check: SP 5- 804-008 to 009) 3. Replace the I/O control board. 4. Replace the main control board. 5. Check the feed unit drive section and if anything causes overload. [ Signal Check ] • Motor OK: CN230-A1 or TP269 on I/O control board

• Code: SC522
• Description: Duplex - Side fence jogger H.P. error - Timing & Condition - • The home position is still detected a few seconds after the side fence leaves from the home position. • The home position is not detected 12 seconds after the side fence moves back to the home position.
• Causes: • Duplex unit not set properly • Excessive load • Poor connection of connector • Defective side fence motor • Defective I/O control board
• Remedy: 1. Pull out and re-insert the duplex unit. 2. Check the connector (CN488) is properly connected on the duplex control board. 3. Check if anything causes overload to the motor. 4. Replace the side fence motor (Output Check: SP 5-804 093 and 094). 5. Replace the I/O control board. [ Signal Check ] Duplex Side Fence H.P.: CN207-B6 or TP293 on I/O control board

• Code: SC524
• Description: Duplex - End fence jogger H.P. error - Timing & Condition - • The home position is still detected a few seconds after the end fence leaves from the home position. • The home position is not detected 24 seconds after the end fence moves back to the home position.
• Causes: • Duplex unit not set properly • Excessive load • Poor connection of connector • Defective end fence motor • Defective I/O control board
• Remedy: 1. Pull out and re-insert the duplex unit. 2. Check the connector (CN484) is properly connected on the duplex control board. 3. Check if anything causes overload to the motor. 4. Replace the end fence motor (Output Check: SP 5-804 095 and 096). 5. Replace the I/O control board. [ Signal Check ] Duplex End Fence H.P.: CN207-B7 or TP288 on I/O control board

• Code: SC541
• Description: Hot roller thermistor open - Timing - at every 1 second when the fusing unit is set - Condition - The hot roller thermistor output is almost close to 5V, which is correspond to 0°C, for 6 seconds continuously
• Causes: • Fusing unit not set properly • Poor connection of connector • Defective thermistor • Defective I/O control board • Defective main control board
• Remedy: 1. Check if the fusing unit is properly set. 2. Check if the thermistor connector is properly connected. 3. Replace the thermistor if it is deformed. 4. Replace the thermistor if it is opened by measuring the resistance. (Refer to the attached Temperature/ Resistance Conversion Reference Table.) 5. Replace the I/O control board. 6. Replace the main control board. [ Signal Check ] • Thermistor: CN214-A4, TP234, or CN211-B1 on I/O control board / CN302-B9 or TP117 on main control board.

• Code: SC542
• Description: Hot roller warm-up error - Timing & Condition - The hot roller thermistor does not output an analog value corresponding to the ready temperature within 12 minutes after the main switch is turned on.
• Causes: • Poor connection of connectors • Hot roller fusing lamp brown • Hot roller thermofuse opened • Power fluctuation • Defective main control board • Defective I/O control board • Defective AC drive board
• Remedy: 1. Check if the following connectors are properly connected; • Hot roller fusing lamp connectors • CN303 on the main control board • CN212 and CN229 on the I/O control board • CN7 on the AC drive board 2. Replace the hot roller fusing lamp if it is opened. 3. Replace the hot roller thermofuse if it is opened. 4. Check if the power supplied from the outlet fluctuates. 5. Replace the main control board, I/O control board, or AC drive board by checking the trigger signal at each pin. [ Signal Check ] • Hot roller fusing trigger: CN303-B6 on main control board / CN212-B6, TP248, or CN229-5 on I/O control board / CN7-6 on AC drive board.

• Code: SC543
• Description: Hot roller fusing lamp overheat - Timing - at every 1 second when the fusing unit is set - Condition - The hot roller thermistor output is lower than about 0.3V, which is correspond to 220°C, for 3 seconds continuously.
• Causes: • Fusing unit not set properly • Poor connection of connector • Defective thermistor • Defective I/O control board • Defective main control board • Defective AC drive board
• Remedy: 1. Check if the fusing unit is properly set. 2. Check if the thermistor connector is properly connected. 3. Replace the thermistor if it is deformed. 4. Replace the thermistor if it is opened by measuring the resistance. (Refer to the attached Temperature/ Resistance Conversion Reference Table.) 5. Replace the main control board, I/O control board, or AC drive board by checking output from the thermistor and the trigger signal at each pin. [ Signal Check ] • Thermistor: CN214-A4, TP234, or CN211-B1 on I/O control board / CN302-B9 or TP117 on main control board. • Hot roller fusing trigger: CN303-B6 on main control board / CN212-B6, TP248, or CN229-5 on I/O control board / CN7-6 on AC drive board.