Canon NP-2020, Service Manual

Page: 86 / 207

C. Fixing Assembly and
ery Assembly
b. NP2120
1.
when the black developing assembly and
pick-up from the cassette,
A3, LTR, or Il
switched to control; 170°C
switched to 175%
The upper and lower rollers of fixing
bly and the delivery roller of the delivery assembly
are driven by the main motor (Mi).
The upper roller has a heater W),
which heats the roller.
The DC controller the surface
of the upper roller by a thermistor (TH) to make
that it remain as specified.
The specifics of the control are as follows:
when the blackdeveloping assembly and
pick-up from the multifeeder,
185°C control; paper shorter
than switched to
control
a. NP2020
when the CT unit and from the
cassette,
If B4, A3, LTR, or
switched control: otherwise, 150°C
switched
when the black developing assembly
control temperature
(standby/copying) 170°C
control temperature (pre-heat)
when the CT unit
control temperature (standbylcopying) 150°C
control temperature (pre-heat)
when the CT unit and pick-up from the
multifeeder,
to control; otherwise, if paper shorter
than 165°C control as
b. NP2120
when the black developing assembly
control temperature
preheat) 155°C
when the CT unit
control temperature (standby/pre-heat) .
control temperature (copying) 1
6 5 ”
To prevent lowering of the surface temperate
of the upper rollerduring copying. the
control switched as follows when copying lasts
about 15 seconds.
a. NP2020
when the black developing assembly
If small-size paper 170°C switched to
175°C control
If
paper switched to
control
when the CT unit
If small-size paper 150°C switched to
155°C control
If
paperis switched to
165°C control
The equipped with the following four
types (or three types if NP2020) of protection
mechanism to prevent the fixing heater from
going at the wrong timing.
The microprocessor the of
TH1 when it finds error, issues or
the SERVICE HANDBOOK.)
If the of TH1 lowers to about 1 .O V or
lower (220°C equivalent), the error detection
off the power to fixing heater
regardless of the output of the microprocessor.
3-57.)
the temperature of the thermoswitch exceeds
the thermoswitch goes OFF to cut off
the power to the fixing heater.
If the SSR detection PCB the
of the SSR, it sends the SSR
to the DC controller PCB. In response, the DC
controller PCB compares the output timing of
the HTRD
and the SSR timing,
issuing E004 identification of error
(applies to NP2120 only: the SERVICE
HANDBOOK).
Note:
Note:
Small-size papers A4, LTR, and
papers A3, 1
LGL
Do not use thermal switch (TS) once has
opened; cannot purpose unless
0°C or not to normal
ambient temperature.
3-44
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