541 A
Fusing thermistor open
The fusing temperature detected by the
center thermistor was below 0°C for 7
sec.
• Thermistor open
• Thermistor connector defective
• Thermistor damaged, or out of position
• Fusing temperature –15% less than the
standard input voltage
542 A
Fusing temperature warm-up error
One of the following occurred:
After power on, or after closing the
front door, the hot roller does not reach
the 100°C control temperature within
25 s.
5 sec. after temperature rise started,
temperature remained below 21°C af-
ter 5 samplings.
Fusing unit did not attain reload tem-
perature within 48 sec. of the start of
fusing temperature control.
• Fusing lamp disconnected
• Thermistor warped, out of position
• Thermostat not operating
543 A
Fusing lamp overheat error 1 (software)
Central thermistor detected a temper-
ature of 240°C at the center of the hot
roller. Fusing temperature control soft-
ware error
• PSU defective
• IOB defective
• BICU defective
544 A
Fusing lamp overheat error 1 (hardware)
The center thermistor or an end ther-
mistor detected a temperature of 250°
C on the hot roller.
• PSU defective
• IOB defective
• BICU defective
545 A
Fusing lamp overheat error 2
After hot roller reaches warmup tem-
perature, the fusing lamps remained on
• Thermistor damaged, or out of position
• Fusing lamp disconnected
4. Troubleshooting
260
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