Ricoh Aficio 480W Dolphin-C2 Service Manual page 159

28 April 2005
SC541 A Fusing thermistor open
The fusing temperature detected
by the thermistor was below
o
13 C (55.4
one 1 s.
SC542 A Fusing temperature warm-up error
After switching on the machine,
or after opening and closing the
machine, during warmup the hot
roller did not attain the ready
temperature within 5 minutes
(the temperature was detected
below 2
SC543 A Fusing overheat error 1 (software)
A fusing temperature of over 215
°C (419°F) was detected for 5 s
SC544 A Fusing overheat error 2 (hardware)
The BCU backup circuit detects
an overheat error even if the
software overheat protection
does not work.
SC545 A Fusing lamp overheat error 3
After reaching the ready
temperature, the hot roller does not
start to rotate and the fusing lamp
stays on at full power for 60 s.
SC546 A Unstable fusing temperature
Fusing temperature is rapidly fluctuating
more than 20°C (68°F) at 1 s intervals.
-or-
Fusing temperature fluctuating over a long
period. It fluctuates 20°C (68°F) more than
3 times during 60 s interval.
o
F) 60 times within
o
C 5 times within 5 s).
4-7
SERVICE CALL CONDITIONS
• Fusing thermistor defective
• Thermistor cable disconnected, broken
• Fusing lamp defective
• Fusing thermistor defective
• Thermistor floating, out of position
• Thermistor cable disconnected, broken
• IOB board defective
• BCU board defective
• PSU defective
• TRIAC short
• TRIAC short
• IOB board defective
• BCU board defective
• PSU board defective
• Hot roller thermistor not positioned
correctly
• Fusing lamp defective
• Thermostat defective
• Poor thermistor connection