Brother HL 1240 - B/W Laser Printer Service Manual page 6

TABLE OF CONTENTS
2.6.2 Exposure stage ................................................................................................................. 3-22
2.6.3 Developing ........................................................................................................................ 3-23
2.6.4 Transfer............................................................................................................................. 3-24
2.6.5 Fixing stage....................................................................................................................... 3-24
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY ..............................4-1
1. SAFETY PRECAUTIONS ................................ ................................ ........................ 4-1
2. DISASSEMBLY FLOW ................................ ................................ ............................ 4-2
3. DISASSEMBLY PROCEDURE ................................ ................................ ................4-3
3.1 AC Cord ............................................................................................................................4-3
3.2 Drum Unit..........................................................................................................................4-3
3.3 Paper Cassette .................................................................................................................4-4
3.4 Front Cover .....................................................................................................................4-10
3.5 Top Cover .......................................................................................................................4-11
3.6 Main Cover......................................................................................................................4-12
3.7 Laser Unit........................................................................................................................4-13
3.8 Drive Unit ........................................................................................................................4-14
3.9 Fixing Unit .......................................................................................................................4-17
3.10 Base Plate.......................................................................................................................4-25
3.11 Main PCB ASSY .............................................................................................................4-26
3.12 Lower Tray Relay PCB ASSY (HL-1250 only)................................................................4-26
3.13 Low-voltage Power Supply PCB ASSY ..........................................................................4-27
3.14 Engine PCB ASSY / High-voltage Power Supply PCB ASSY ........................................4-28
3.15 Panel PCB ASSY............................................................................................................4-30
3.16 Solenoid ASSY ...............................................................................................................4-30
3.17 Fan Motor ASSY .............................................................................................................4-33
3.18 Toner Sensor PCB ASSY (Light Emission) ....................................................................4-34
3.19 Toner Sensor PCB ASSY (Light Reception)...................................................................4-34
3.20 Paper Pick-up Roller ASSY ............................................................................................4-35
3.21 Paper Feed Roller ASSY ................................................................................................4-36
4. PACKING ................................ ................................ ................................ ..............4-37
CHAPTER 5 PERIODIC MAINTENANCE ...............................................5-1
1. CONSUMABLE PARTS ................................ ................................ ........................... 5-1
1.1 Drum Unit..........................................................................................................................5-1
1.2 Toner Cartridge.................................................................................................................5-2
2. PERIODICAL REPLACEMENT PARTS................................ ................................ ...5-4
3. PERIODICAL CLEANING ................................ ................................ ........................ 5-5
3.1 Cleaning the Printer Exterior.............................................................................................5-5
3.2 Cleaning the Drum Unit.....................................................................................................5-5
3.3 Cleaning the Scanner Window..........................................................................................5-6
3.4 Cleaning the Electrical Terminals .....................................................................................5-6
4. MTBF / MTTR ................................ ................................ ................................ ..........5-7
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