Carriage Relay Pcb; Carriage Relay Pcb Components; Head Relay Pcb; Head Relay Pcb Components - Canon iPF720 Service Manual

This IC generates feed motor control signal based on the control signal from the ASIC.
d) Driver IC (IC2900)
This IC generates purge motor and valve motor control signals based on the control signal from the ASIC.
e) Driver IC (IC2902)
This IC generates a lift motor control signal based on the control signal from the ASIC.
f) DIMMs (IC301,IC302,IC601,IC602,IC603,IC604)
The DIMM comprising a 128-MB DDR-SDRAM and a 128-MB SDR-SDRAM is connected to the 32-bit data bus to be used as a work area.
During print data reception, it is also used as an image buffer.
It cannot be expanded.
g) FLASH ROM (IC701)
A 16-MB flash ROM is connected to the 8-bit data bus to store the printer control program.
h) EEPROM (IC802)
The 128-KB EEPROM stores various setting values, adjustment values, log data, counter values related to the user/servicing.
i) HDD controller (IC1201)
This controller control the hard disk drive.
MEMO:
After replacement of the main controller PCB, the printer must be started up in the service mode to take over the setting and adjustment values to the new PCB
properly (the service mode will be switched to the PCB replacement mode automatically).

2.4.3 Carriage Relay PCB

2.4.3.1 Carriage relay PCB components

a) Regulator IC (IC302)
This IC generates power for the printhead heater.

2.4.4 Head Relay PCB

2.4.4.1 Head relay PCB components

a) Latch IC (IC201)
DI sensor read control function
Obtains reading value of the DI sensor in the printhead and the head rank value for each color and outputs them to the main controller based on the control commands
from the main controller.
Environment temperature read control function
Outputs the environment temperature detected by the thermistor on the head relay PCB to the main controller based on the control commands from the main con-
troller.
Relay function of the power to the logic components in the printhead
Supplies the power to the logic components in the printhead based on the control commands from the main controller.
b) Thermistor (TH201)
The environment temperature surrounding the head relay PCB detected by this thermistor is output to the main controller through the carriage relay PCB.
c) Multi sensor control IC (IC204, IC205)
These IC's generates the LED control signals and makes gain adjustment for the multi sensor.
F-2-27
IC204
TH201
IC201
F-2-28
IC302
IC205
Chapter 2
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0012-6318
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