Canon i-SENSYS LBP5300 Series Service Manual

Also see for i-SENSYS LBP5300 Series: User guide User guide

Contents

Chapter 22-37The low-voltage power supply circuit is to convert AC into DC covering the DC loads.The block diagram of this circuit is illustrated below.F-2-47The low-voltage power supply circuit is partially activated as soon as plugged in the electrical outlet. When turning ON the power switch (SW3701), whole low-voltage power supply works.The AC power is then converted into +24V, +5V and +3.3V covering each of printer DC loads.The following are the main loads for +24V, +5V and +3.3V power.+24V: Motors, solenoids, high-voltage power supply PCB, and 500-sheet paper feeder+5VÅF +5V: Laser driver PCB, high-voltage power supply PCB, color misregistration/image density sensor, control panel, and memory controller PCB+3.3V: Sensor (photo interrupter), media sensor, environment sensor, video controller, control panel, DC controller, and high-voltage power supply PCB2.7.1.2 Other Function2.7.1.2.1 Protective function0013-8413/ i-SENSYS LBP5360 / i-SENSYS LBP5300The low-voltage power supply circuit has protective function against overcurrent and overvoltage to prevent failures in the power supply circuit. Once there flowsan excessive current accidentally to the load side for some trouble such as a short-circuit problem, or overvoltage occurs, it automatically cuts off the output voltage.In case that no DC voltage is supplied from the low-voltage power supply circuit, turn off the power switch (SW3701) anyway. Do not turn on the power again asfar as the root cause is not found at the load side since the protective function may still work. (see Note) There are two fuses, FU3801 and FU3901, in the circuitfor other protective function. The fuses blow and cut off the AC power, once AC overcurrent flows into the AC line.To recover the low-voltage power supply in case of functioning the protection, turn the power OFF (by switching off or unplugging) and leave the printer off for15 seconds or longer, then turn the printer ON again.2.7.1.2.2 Safety0013-8415/ i-SENSYS LBP5360 / i-SENSYS LBP5300For the safety reason for the users and the service technicians, the +24V DC line is intentionally divided into two ways, +24VA and +24VB.The +24VA is supplied from the DC controller all the time, whereas the power supply of the +24VB stops when the door switch (SW1) is cut off. The high-voltagepower supply PCB and motors are supplied with the +24VB. They stop when the front cover or upper cover is opened.This is to protect the users and the service technicians from an electric shock or injury to their hands.The +24VB also functions as the DOOR OPEN signal. The CPU determines the door open when the +24VB supply stops.2.7.1.2.3 Sleep function0013-8417/ i-SENSYS LBP5360 / i-SENSYS LBP5300IC1001CPUNoise filterFusePower switchFuseNoise filterLow-voltage power supply circuitRemote switchcontrol circuitZero crossingcircuit24V generation circuitIC1010ASICPS100V3.3V5V24VAPSREM24VZEROXPSOFF/PSSWOPENRSRDRLD-DCcontrollerDriver ICDoor opendetection switch24VA 24VB24VA 24VB3.3VRLD+Fixing unit3.3VDuplexing unit Paper feeder (Option)3.3V24VBFeed motor, Drum motor, ETB motor,Fixing motor, Solenoids24VBPhotointerrupters3.3VHigh-voltage power supply PCB3.3V24VB5VFan Scanner motor24VALaser PCB5V5V3.3VMemory controller PCBEnvironment sensorPhotointerrupters3.3V5V3.3V Video controller PCBControl panelLow-voltage power supply unitColor misregistration/Image densitysensorSW3701FU3801FU3901Protective circuitFixing contlolcircuit24V ON/OFFcircuit3.3V generation circuit5V generation circuitPrinter power supllyvoltage detection circuit