Toshiba e-STUDIO 4500c, Service Manual

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April, 2007 SERVICE CALL CONDITIONS
4-51
Heating roller thermistor 1 error 3: Software - High temperature SC543 A
The thermistor detected a
temperature over 230
°
C.
•
TRIAC short
•
IOB defective
•
BICU defective
•
Fusing temperature out of control
Do SP5810 to cancel the SC fusing code.
Heating roller thermistor 1 error 4: Hardware - High temperature SC544 A
The thermistor detected a
temperature over 260
°
C.
•
TRIAC short
•
IOB defective
•
BICU defective
•
Fusing temperature control is erratic
Do SP5810 to cancel the SC fusing code.
Heating roller thermistor 1 error 5: Lamp remains ON SC545 A
After hot roller reaches warmup
temperature, the fusing lamps
remained ON at full capacity for
25 sec. after reaching the
warmup temperature while the
hot roller was not rotating.
•
Thermistor damaged, or out of position
•
Fusing lamp disconnected, broken
Do SP5810 to cancel the SC fusing code.
Heating roller thermistor 2 error 1: Thermistor disconnected SC546 A
The temperature measured by
the heating roller thermistor
does not reach 0°C after 45 sec.
and remains over this
temperature for 10 readings.
•
Loose connection of the heating roller
thermistor
•
Defective heating roller thermistor
Zero cross error SC547 A
When the main switch is turned ON, the
machine checks how many zero-cross
signals are generated within 500 ms. This
SC code is issued if the number of zero-
cross signals detected is either more than 66
or less than 45 for 10 readings.
Note: Zero cross signals, generated from an
ac power supply, are used to generate a
trigger pulses to control the applied power
accurately.
•
Electrical noise on the power
supply line
•
Fusing relay damaged:
replace the PSU.
Normally, this SC is cancelled if you do SP5810 to cancel the SC fusing code.