• Code: SC544
• Description: Hot roller fusing lamp lower temperature - Timing - at every 1 second after the warm-up is completed - Condition - The hot roller thermistor output is higher than about 3V, which is correspond to 87°C, for 8 seconds continuously after the warmup is completed.
• 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.

• Code: SC545
• Description: Hot roller ready temperature abnormal - Timing - at every 1 second after the temperature reaches to the ready condition - Condition - The hot roller thermistor output does not reach to the ready temperature within 7 minutes 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.

• Code: SC547
• Description: Hot roller temperature does not increase - Timing - at every 1 second, 2minutes after the main switch turned on and before the hot roller temperature does not reach to the ready condition - Condition - The fusing roller temperature does not increase by no more than 3°C for a minutes during warm-up.
• Causes: • Poor connection of connectors • Hot roller fusing lamp brown • Hot roller thermofuse opened • 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. 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: SC551
• Description: Pressure roller thermistor open - Timing - at every 1 second after the fusing unit is set - Condition - The pressure 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-A9, TP232, or CN211-B2 on I/O control board / CN302-B8 or TP118 on main control board

• Code: SC552
• Description: Pressure roller warm-up error - Timing & Condition - The pressure 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 • Pressure roller fusing lamp brown • Pressure roller thermofuse opened • Brown fuse • 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; • Pressure 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 ] • Pressure roller fusing trigger: CN303-B7 on main control board / CN212-B5, TP240, or CN229-4 on I/O control board / CN7-7 on AC drive board.

• Code: SC553
• Description: Pressure roller overheat - Timing - at every 1 second when the fusing unit is set - Condition - The pressure 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-A9, TP232, or CN211-B2 on I/O control board / CN302-B8 or TP118 on main control board. • Pressure roller fusing trigger: CN303-B7 on main control board / CN212-B5, TP240, or CN229-4 on I/O control board / CN7-7 on AC drive board.

• Code: SC554
• Description: Pressure roller low temperature - Timing - at every 1 second after the warm-up is completed - Condition - The pressure roller thermistor output is higher than about 3V, which is correspond to 87°C, for 8 seconds continuously after the warm-up is completed.
• 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-A9, TP232, or CN211-B2 on I/O control board / CN302-B8 or TP118 on main control board. • Pressure roller fusing trigger: CN303-B7 on main control board / CN212-B5, TP240, or CN229-4 on I/O control board / CN7-7 on AC drive board.

• Code: SC555
• Description: Pressure roller ready temperature abnormal - Timing - at every 1 second after the temperature reaches to the ready condition - Condition - The pressure roller thermistor output does not reach to the ready temperature within 7 minutes 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-A9, TP232, or CN211-B2 on I/O control board / CN302-B8 or TP118 on main control board. • Pressure roller fusing trigger: CN303-B7 on main control board / CN212-B5, TP240, or CN229-4 on I/O control board / CN7-7 on AC drive board.