Canon 3370 Series Service Manual page 50

Chapter 2
Fixing unit
AC input
Fan
Transfer
charging roller
Pressure roller
Cartridge
Memory tag
a. CPU (IC201)
The CPU uses one 8-bit single-chip microprocessor IC.
It is a single-chip type CPU with built-in ROM and RAM. The CPU controls the following printer operations according to the control programs stored in the
ROM.
1) Printer sequence
2) Communications with the video controller
3) High-voltage power supply circuit
4) Laser/ scanner
5) Sensors
6) Loads (motor, solenoid etc.)
7) Fixing control circuit
8) Duplex driver PCB (Duplex model only)
9) Option
b. Reset IC (IC502)
The IC502 monitors the +3.3V and resets the CPU when the power switch is turned ON.
c. Memory tag circuit
The memory tag circuit reads/writes the data into/on the memory tag inside a cartridge according to the command from the CPU (IC201).
d. Fixing control circuit
The fixing control circuit controls the temperature of the fixing unit according to the command from the CPU (IC201).
e. High-voltage power supply circuit
The high-voltage power supply circuit generates the high-voltage power supply according to the command from the CPU (IC201).
f. Low-voltage power supply circuit
The low-voltage power supply circuit generates the DC power supply required by the printer when the power switch is turned ON.
g. Fan motor drive circuit
The fan motor drive circuit drives the fan motor according to the command from the CPU (IC201).
2-22
Engine controller PCB
Fixing control
circuit
Low-voltage power
supply circuit
Fan motor drive
circuit
Reset Circuit
High-voltage
power supply
circuit
Memory tag circuit
Video controller PCB
F-2-28
Duplex driver
(Duplex model
IC201
CPU
Scanner motor
Laser driver
Main motor
Solenoids
Sensors
PCB
only)
Option
BD sensor