SERVICE CALL CONDITIONS
B135/B138 4-10 SM
Code No. Symptom Possible Cause
Fusing overheat error (hardware circuit
detection)
544 A
The dual monitoring circuitry of the
BICU detects extremely high
temperature and tripped the relay circuit
off.
• Power supply unit defective
• I/O board (IOB) defective
• BICU defective
• Fusing thermistor defective
Fusing lamp remains on 545 A
After warm-up the fusing lamp remains
at full power for 10 seconds without the
hot roller rotating.
• Thermistor is out of position.
Fusing ready temperature unstable 546 A
The fusing temperature is fluctuating.
• Thermistor connection loose
• Fusing unit connector loose
Zero cross signal malfunction 547 B
The applied power supply ac frequency
was detected at over 66Hz or below
45Hz, and the zero cross signals are
not detected within a certain period
within 500 ms after the main power
switch has been turned on.
• Power supply board defective
• Noise on the ac power line
Fusing unit installation error 548 A
The machine cannot detect the fusing
unit when the front cover and right
cover are closed.
• Fusing unit is not installed
• Fusing unit connection loose
1-bin tray motor lock (optional 1-bin tray
unit)
599 C
A 1-bin tray motor lock signal is not
detected for more than 300 ms during
rotation.
• 1-bin tray motor locked from overload
• 1-bin tray motor defective
• 1-bin tray motor connection loose
Communication error between BICU
and scanner unit
601 C
Within 800 ms after power on, after 3
attempts the BICU does not
communicate with the SIB via the serial
line.
• Serial line connecting the BICU and
SIB defective
• External noise on the serial line
• SIB board defective
• BICU board defective
Communication timeout error between
BICU and ARDF
610 C
The BICU cannot receive a response
within 100 ms after 3 attempts after
sending data to the ARDF.
• BICU board and ARDF main board
serial line connection defective
• External noise
• ARDF main board defective
• BICU board defective
Communication break error between
BICU and ARDF
611 C
The BICU receives a break signal from
the ARDF main board.
• Serial line connecting BICU and
ARDF unstable
• External noise
• ARDF main board defective
• BICU board defective
Communication command error
between BICU and ARDF
612 C
The BICU sends a command to the
ARDF main board that it cannot
execute.
• Abnormal operation performed by
software