Canon imageCLASS MF5600 Series, Service Manual

Page: 44 / 256

Chapter 2
2-12
2.5.2.2
Detecting a Fault in the Fixing Assembly
0002-8630
The CPU identifies a fault in the fixing assembly for the following conditions (a. thorough g.) and operates as
described:
1. the CPU causes the fixing heater drive signal to go Low to cut off the power to the fixing heater.
2. the CPU causes the relay drive signal to go Low to turn off the relay.
3. the CPU, if it detects a fault while printing is under way, discharges the paper being picked up or moved at the
time, and immediately turns off the main motor, scanner motor, and high-voltage system and puts the printer unit
in an error state.
a) the reading of the main thermistor does not exceed 50 deg C within 2.34 sec after the start-up temperature control
mechanism is started.
b) the CPU detects that the reading of the main thermistor remains 235 deg C or more for 1 sec continuously while
fixing temperature control is under way.
c) the CPU detects that the reading of the main thermistor remains 100 deg C or less for 1.2 sec continuously while
paper passage temperature control is under way; or the CPU detects that the reading of the main thermistor remains
50 deg C or less for 0.3 sec continuously while between-sheets temperature control is under way.
d) the CPU detects that the reading of the main thermistor remains less than 20 deg C for 0.3 sec continuously while
fixing heater temperature control is under way.
e) the temperature of the main thermistor does not exceed 100 deg C within 20 sec after the start of start-up
temperature control.
f) the CPU detects that the reading of the sub thermistor remains less than 35 deg C for 0.15 sec continuously while
fixing heater temperature control is under way.
g) the CPU detects that the reading of the sub thermistor remains 320 deg C for 0.15 sec continuously while fixing
heater temperature control is under way.