Brother mfc8440 Service Manual page 6

TABLE OF CONTENTS
2.4.9 Rear cover sensor............................................................................................................. 3-21
2.4.10 HP sensor ......................................................................................................................... 3-21
2.5 Drum Unit ....................................................................................................................... 3-22
2.5.1 Photosensitive drum.......................................................................................................... 3-22
2.5.2 Primary charger................................................................................................................. 3-22
2.5.3 Transfer roller.................................................................................................................... 3-22
2.5.4 Cleaner ............................................................................................................................. 3-22
2.6 Toner Cartridge .............................................................................................................. 3-22
2.7 Print Process.................................................................................................................. 3-22
2.7.1 Charging ........................................................................................................................... 3-22
2.7.2 Exposure stage ................................................................................................................. 3-23
2.7.3 Developing ........................................................................................................................ 3-24
2.7.4 Transfer............................................................................................................................. 3-24
2.7.5 Fixing stage....................................................................................................................... 3-25
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 Tray ....................................................................................................................... 4-4
3.4 DX Feed ASSY (MFC-8840D/8840DN, DCP-8045D/8045DN only) ............................. 4-14
3.5 Access Cover / Battery .................................................................................................. 4-17
3.6 Driver PCB Access Cover.............................................................................................. 4-18
3.7 ADF Unit......................................................................................................................... 4-19
3.8 Document Scanner ........................................................................................................ 4-28
3.9 Panel Unit....................................................................................................................... 4-33
3.10 Rear Cover C (MFC-8440, DCP-8040 only) .................................................................. 4-36
3.11 Outer Chute (MFC-8440, DCP-8040 only) .................................................................... 4-37
3.12 Rear Cover MP ASSY / Outer Chute MP ASSY
(MFC-8840D/8840DN, DCP-8045D/8045DN only) ....................................................... 4-38
3.13 Rear Cover L/R .............................................................................................................. 4-39
3.14 Side Cover L/R............................................................................................................... 4-40
3.15 Joint Cover ..................................................................................................................... 4-41
3.16 Front Cover ASSY (MFC-8440, DCP-8040 only) .......................................................... 4-46
3.17 MP Unit (MFC-8840D/8840DN, DCP-8045D/8045DN only) ......................................... 4-47
3.18 Rear Cover Sensor ........................................................................................................ 4-52
3.19 NCU (MFC-8440/8840D/8840DN only) ......................................................................... 4-53
3.20 Fixing Unit ...................................................................................................................... 4-54
3.21 Laser Unit....................................................................................................................... 4-63
3.22 Main PCB ....................................................................................................................... 4-65
3.23 Base Plate / LV Insulation Sheet ................................................................................... 4-67
3.24 DX-Sensor PCB ASSY (MFC-8840D/8840DN, DCP-8045D/8045DN only) ................. 4-68
3.25 Engine PCB.................................................................................................................... 4-69
3.26 High-voltage PS PCB ASSY .......................................................................................... 4-70
3.27 Low-voltage PS PCB ASSY........................................................................................... 4-71
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