Canon LBP 2460 Service Manual - Page 140

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. Power supply Fuse Noise filter Remote contorol circuit Smoothing circuit Transformer Smoothing circuit Control IC Overcurrent protection curcuit Overcurrent protection curcuit PWRON-IN Option PWRON-IN controller PCB +24V +5V Paper deck driver PCB +5V +24V Switches /sensors Solenoids +24V Clutches +24V Motors Figure 2-10-14 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. 2 - 94