Canon PC-D320, Service Manual

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PC-D320/PC-D340/FAX-L400 Chapter 2: Technical Reference
2-17
4.4 Fixing Section
This section comprises the fixing ass’y and pressure roller. The fixing section on this machine is
an on-demand method that uses fixing film with low thermal capacity.
The toner that was transferred to the recording paper at the toner transfer section is fused to the
paper and fixed as a permanent image.
The fixing ass’y has a built-in fixing heater and thermistor.
4.4.1 Fixing unit Malfunction
The CPU on the ECNT board assesses a fixing unit malfunction under the conditions a) to g)
indicated below and it performs the following three procedures:
1. Cuts off power to the fixing heater by setting the FIXING HEATER DRIVE
(FSRD:ECNT board-IC201-39pin) signal “L”.
2. Sets the RELAY DRIVE (RLYD:ECNT board-IC201-38pin) signal “L” to turn OFF the
relay (RL101:ECNT board-RL101).
3. Stops the main motor, scanner motor, and high-voltage power supply system
immediately, and then sets the printer an error state and notifies the malfunction to the
SCNT board.
a) The main thermistor does not exceed 50 °C within 1.47 seconds after the start of start-
up temperature control.
b) The main thermistor remains 230 °C or more continuously for 1.5 seconds during fixing
heater temperature control.
c) The temperature of the main thermistor is 100°C or less continuously for 1.5 seconds
during normal temperature control. Or, the main thermistor remains 50°C or less
continuously for 1.5 seconds during between-sheet temperature control.
d) The temperature of the main thermistor remains less than 20°C continuously for 3
seconds during fixing heater temperature control.
e) The main thermistor does not exceed 100 °C within 30 seconds after the start of start-up
temperature control.
f) The sub thermistor remains less than 20 °C continuously for 1.5 seconds during fixing
heater temperature control.
g) The temperature of the sub thermistor is 320°C or more continuously for 3 seconds
during fixing heater temperature control.