Brother FAX-2820 Service Manual page 45

CHAPTER 3 THEORY OF OPERATION
This chapter gives an overview of the scanning and printing mechanisms as well as the sensors,
actuators, and control electronics. It aids in understanding the basic principles of operation as
well as locating defects for troubleshooting.
3.1 OVERVIEW ......................................................................................................................3-1
3.2 MECHANICAL COMPONENTS.......................................................................................3-2
3.2.1 Scanner Mechanism ............................................................................................3-3
3.2.2 Document Feeding and Ejecting Mechanism.......................................................3-3
3.2.3 Scanner ................................................................................................................3-3
3.2.4 Printing Mechanism..............................................................................................3-4
3.2.4.1 Paper supply ................................................................................................3-4
3.2.4.2 Push-up function of paper tray.....................................................................3-6
3.2.4.3 Paper registration.........................................................................................3-8
3.2.4.4 Paper eject ...................................................................................................3-9
3.2.4.5 Drum unit......................................................................................................3-9
3.2.4.6 Toner cartridge...........................................................................................3-10
3.2.4.7 Print process ..............................................................................................3-13
3.2.5 Sensors and Actuators .......................................................................................3-16
3.3 CONTROL ELECTRONICS...........................................................................................3-17
3.3.1 Components .......................................................................................................3-17
CONTENTS
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