Ricoh Neptune-P1 Service Manual page 197

4. Troubleshooting
The circuit on the MCU that monitors the temperature
of the board detected a fusing temperature of 230
(446
544 A Fusing Temperature: Error 2 (Hardware Detection)
The fusing thermistor that monitors the temperature of
the hot roller detected a fusing temperature of 235
(455
fusing temperature control.
4
545 A Fusing Temperature: Error 3
After the hot roller reached the ready
temperature, the fusing lamp stayed
on at full power for 50 sec. while the
hot roller was not rotating.
546 A Fusing Temperature: Error 4
The machine detected that the fusing
temperature was fluctuating out of range for
more than 60 sec. (7 readings detected
temperature fluctuating more than ±20
547 D Zero-Cross Signal Errors
This error occurs if the machine fails to detect
50/60 Hz on the power supply line.
Note: The zero-cross signal from the ac
power supply generates a trigger pulse to
control the power supply of power. (It
automatically detects 50/60 Hz.)
551 A Pressure roller center thermistor error 1
196
o
F) for longer than 2 sec.
o
F), due to a Triac short which interfered with
o
C • MCU defective
• MCU defective
o
C
• PSU defective
• Fusing unit defective
• Hot roller thermistor not positioned correctly
• Fusing lamp harness loose, disconnected,
defective
• MCU defective
• Thermistor connection loose,
disconnected, defective
• Hot roller thermistor not positioned
correctly
• Fusing lamp connections loose,
o
C)
disconnected, defective
• MCU defective
• Check that the frequency of the power
supply to the machine is correct
• PSU defective
• MCU defective