Power Supply - Canon LBP 2460 - B/W Laser Printer Service Manual

CHAPTER 2
G. Power Supply
1. Outline
This machine's power supply utilizes the remote switch method.
When the printer is turned ON, the printer outputs commands to the option controller through the
video controller. The option controller outputs a POWER ON signal (PWRON-IN) to the power
supply through the paper deck driver to turn the power ON. When PWRON-IN signal turns "H",
the power supply circuit supplies the paper deck driver with +24V and +5V.
+24V is used to drive the deck motor, pick-up motor, clutch and solenoid etc., and +5V is for
the sensors and ICs etc. on the paper deck driver PCB.
This is outlined in the block diagram below.
Fuse
Noise
filter
2. Protection System
On the various +24V and +5V power supply circuits is an overcurrent protection system which
automatically cuts the output voltage protecting the circuits from being damaged in the event that
overcurrent should flow due to some form of trouble or from one of the loads shorting.
Therefore, when the overcurrent protection circuit is activated and DC voltage is not being output
from the power supply circuit, after turning the printer power OFF and rectifying the problem,
turn the power ON again.
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Power supply

Remote
contorol
Smoothing
circuit
Transformer
circuit
Control IC
Overcurrent
protection
curcuit
Figure 2-10-14
PWRON-IN
+24V
Smoothing
+5V Paper deck
circuit
driver PCB
Overcurrent
protection
curcuit
Option
PWRON-IN
controller
PCB
Switches
+5V
/sensors
+24V
Solenoids
+24V
Clutches
+24V
Motors