error Fusing temperature 541

541	Fusing thermistor open (center)
	The temperature of the hot roller remained below 0C for 5 sec at the center of the hot roller.	• Fusing thermistor out of its position because of incorrect installation • Fusing thermistor disconnected or defective • Power supply not within rated range (15% or more below rating)
542	Fusing temperature warm-up error (center)
	The fusing temperature did not reach the standby temperature within 20 sec. at the center of the hot roller after the main switch turned on.	• Fusing thermistor defective or out of position • Fusing lamp disconnected • Thermistor defective • Fusing lamp defective
543	Fusing overheat error 1 (center)
	The fusing thermistor detected a fusing temperature over 230 °C for 5 sec. at the center of the hot roller.	• TRIAC short on PSU (PSU defective) • BCU board defective • Fusing thermistor defective
544	Fusing overheat error 2 (center)
	A fusing temperature over 250 °C is detected at the center of the hot roller by the fusing temperature monitor circuit in the BCU board. The power was interrupted for more than 0.3 sec.	• TRIAC short on PSU (PSU defective) • BCU board defective • Fusing thermistor defective • Power supply voltage unstable
545	Fusing overheat error 3 (center)
	After warmup, the center of the hot roller attained full operating temperature and maintained this temperature for 10 sec. without the hot roller rotating.	• Center hot roller thermistor installed incorrectly, disconnected. • Center hot roller thermistor defective
547	Zero cross signal detection error
	Zero cross signals were not detected within the prescribed time.	• PSU, BCU harness loose or broken • PSU defective • BCU defective
551	Fusing thermistor open (end)
	The temperature of the hot roller remained below 0C for 5 sec. at the end of the hot roller.	• Fusing thermistor out of its position because of incorrect installation • Fusing thermistor disconnected or defective • Power supply not within rated range (15% or more below rating)
552	Fusing temperature warm-up error (end)
	The fusing temperature did not reach the standby temperature within 20 sec. at the center of the hot roller after the main switch turned on.	• Fusing thermistor defective or out of position • Fusing lamp disconnected • Thermistor defective • Fusing lamp defective
553	Fusing overheat error 1 (end)
	The fusing thermistor detected a fusing temperature over 230 °C for 5 sec. at the center of the hot roller.	• TRIAC short on PSU (PSU defective) • BCU board defective • Fusing thermistor defective
554	Fusing overheat error 2 (end)
	A fusing temperature over 250 °C is detected at the center of the hot roller by the fusing temperature monitor circuit in the BCU board. The power was interrupted for more than 0.3 sec.	• TRIAC short on PSU (PSU defective) • BCU board defective • Fusing thermistor defective • Power supply voltage unstable
555	Fusing overheat error 3 (end)
	After warmup, the center of the hot roller attained full operating temperature and maintained this temperature for 10 sec. without the hot roller rotating.	• Center hot roller thermistor installed incorrectly, disconnected. • Ce