Contents3.1.5Control Panel PCB....................................................................................................................................... 3- 53.1.6Power Supply PCB ...................................................................................................................................... 3- 53.1.7Analog Processor PCB ................................................................................................................................ 3- 53.1.8Sensor PCB .................................................................................................................................................. 3- 53.1.9Laser Driver/BD PCB.................................................................................................................................. 3- 53.1.10Main Motor/Scanner Motor Driver ........................................................................................................... 3- 53.1.11Printer Controller PCB .............................................................................................................................. 3- 53.1.12NCU PCB (if equipped with fax functions) .............................................................................................. 3- 63.1.13Modular Jack PCB (if equipped with fax functions) ................................................................................. 3- 63.1.14Sensor Relay PCB...................................................................................................................................... 3- 63.1.15Controlling the Main Motor....................................................................................................................... 3- 73.1.16Reproduction Processes ............................................................................................................................. 3- 73.2 Basic Sequence ................................................................................................................................................ 3- 113.2.1Basic Sequence of Operations at Power-On .............................................................................................. 3- 11Chapter 4 Original Exposure System4.1 Construction....................................................................................................................................................... 4- 14.1.1Major Components ...................................................................................................................................... 4- 14.2 Parts Replacement Procedure ............................................................................................................................ 4- 24.2.1 Reader Unit ................................................................................................................................................. 4- 24.2.2 Copyboard glass .......................................................................................................................................... 4- 54.2.3 Sensor PCB ................................................................................................................................................. 4- 54.2.4 Scanner Motor ............................................................................................................................................. 4- 74.2.5 Contact sensor ............................................................................................................................................. 4- 8Chapter 5 Laser Exposure5.1 Construction....................................................................................................................................................... 5- 15.1.1Outline ......................................................................................................................................................... 5- 15.2 Parts Replacement Procedure ............................................................................................................................ 5- 25.2.1 Laser Scanner Unit ...................................................................................................................................... 5- 2Chapter 6 Image Formation6.1 Construction....................................................................................................................................................... 6- 16.1.1Outline ......................................................................................................................................................... 6- 16.2 Parts Replacement Procedure ............................................................................................................................ 6- 26.2.1 Developing Cylinder ................................................................................................................................... 6- 26.2.2 Developing Blade ........................................................................................................................................ 6- 36.2.3 Transfer Charging Roller ............................................................................................................................ 6- 56.2.4 Toner Bottle Sensor..................................................................................................................................... 6- 66.2.5 Waste Toner Full Sensor ............................................................................................................................. 6- 8Chapter 7 Pickup/Feeding System7.1 Construction....................................................................................................................................................... 7- 17.1.1Outline ......................................................................................................................................................... 7- 17.2 Detecting Jams................................................................................................................................................... 7- 3