• Code: 553
• Description: Fusing overheat error (rear)
  The fusing temperature is over 230C for 1 second (detected by the thermistor).
• Causes: - Fusing thermistor defective
  - Power supply board defective

• Code: 555
• Description: Fusing lamp overheat error (rear)
  After the fusing temperature reaches the target temperature, the fusing lamp does not turn off for 20 consecutive seconds.
• Causes: - Fusing thermistor defective or out of position
  - Power supply board defective

• Code: 556
• Description: Unstable fusing temperature (rear)The fusing temperature varies 50C or more within 1 second, and this occurs 2 consecutive times.
• Causes: - Thermistor defective or out of position
  - Power supply unit defective

• Code: 559
• Description: Jam error detected 3 times in succession
  - The exit sensor and the duplex sensor detect a paper jam 3 times in succession
  - This condition can occur when SP 1159 1 is set to ‘on’. The default is ‘off’.
• Causes: Paper jams can occur for the following reasons
  - Dampness
  - Paper curl
  - Incorrect paper setting in the paper tray
  - Stripper pawls coming apart

• Code: 590
• Description: Left exhaust fan motor error
  The CPU detects an exhaust fan lock signal for more than 5 seconds.
• Causes: - Loose connection of the exhaust fan motor
  - Too much load on the motor drive

• Code: 591
• Description: Rear exhaust fan motor error
  The CPU detects an exhaust fan lock signal for more than 5 seconds.
• Causes: - Loose connection of the exhaust fan motor
  - Too much load on the motor drive

• Code: 620
• Description: Communication error between BICU and ADF
  The BICU does not receive a response from the ADF main board for 4 seconds or more. The BICU receives a break signal from the ADF main board.
• Causes: - Poor connection between the BICU and ADF main board (DF connector)
  - ADF main board defective
  - BICU defective

• Code: 621
• Description: ADF connection error
  An incorrect ADF (an ADF for some other copier) is detected. (for Basic and GDI machines) An ADF (including the correct ADF) is installed while the copier is in the energy saver mode. (for GDI machine only)
• Causes: - ADF incorrect (The ADF for B039/B040/B043 or
  B121/B122/B123 is installed on a B245/B268/B269/B276/B277.)
  - The connector of the ADF is removed while the machine is in the energy saver mode.