Ricoh A250 Service Manual page 291

SC544: Fusing Low Temperature Error
Definition: [A]
A fusing temperature of less than 100°C is detected for 1 second by the fusing
thermistor.
Possible Causes:
• Fusing thermistor defective
• Power supply unit defective
SC546: Unstable Fusing Temperature
Definition: [A]
The fusing temperature does not rise 3°C or more within 5 seconds after the
fusing lamp has been on 8 seconds.
Possible Causes:
• Thermistor defective
• Poor connection of the fusing unit
• Power supply unit defective
SC547: Zero Cross Signal Malfunction
Definition: [A]
Zero-cross signals are not detected within a certain period.
Possible Causes:
• Power supply unit defective
• Input output board
• BICU defective
SC620: Communication Error between BICU and ADF
Definition: [B]
The BICU cannot receive a response from the ADF main board for 4 seconds
or more.
Possible Causes:
• Poor connection between the BICU board and ADF main board (DF
connector)
• ADF main board defective
• BICU board defective
SC630: [D] CSS (RSS) Communication Error between Line Adapter and
CSS Center
Japanese version only
SM
SERVICE CALL CONDITIONS
7-7 A250