HL-5240/5250DN/5270DN/5280DW SERVICE MANUAL
iii Confidential
2.3.9 Reset circuit ........................................................................................................................ 2-5
2.3.10 Panel I/O ............................................................................................................................. 2-5
2.3.11 Video I/O ............................................................................................................................. 2-5
2.3.12 Power supply....................................................................................................................... 2-5
2.3.13 Wireless LAN ...................................................................................................................... 2-5
2.4 Power Supply................................................................................................................... 2-6
2.4.1 Low-voltage power supply................................................................................................... 2-6
2.4.2 High-voltage power supply.................................................................................................. 2-6
3. MECHANICS .............................................................................................................2-7
3.1 Overview of Printing Mechanism ..................................................................................... 2-7
3.2 Overview of Gear ............................................................................................................. 2-8
3.3 Paper Transfer ................................................................................................................. 2-9
3.3.1 Paper supply ....................................................................................................................... 2-9
3.3.2 Paper registration.............................................................................................................. 2-11
3.3.3 Drum unit .......................................................................................................................... 2-11
3.3.4 Developing ........................................................................................................................ 2-12
3.3.5 Fixing stage....................................................................................................................... 2-13
3.3.6 Paper eject........................................................................................................................ 2-14
3.3.7 Duplex printing (HL-5250DN/5270DN/5280DW) ............................................................... 2-15
3.3.8 Paper feeding from the MP tray ........................................................................................ 2-16
3.3.9 LT tray............................................................................................................................... 2-16
3.4 Toner Cartridge.............................................................................................................. 2-17
3.4.1 Toner life end mode .......................................................................................................... 2-17
3.4.2 New toner detection mechanism ....................................................................................... 2-19
3.4.3 Counter reset during indication of “Toner Life End”........................................................... 2-20
3.5 Print Process.................................................................................................................. 2-21
3.5.1 Charging ........................................................................................................................... 2-21
3.5.2 Exposure stage ................................................................................................................. 2-21
3.5.3 Transfer............................................................................................................................. 2-22
3.6 Sensors .......................................................................................................................... 2-23
3.7 Heat Control of Fuser Unit ............................................................................................. 2-24
CHAPTER 3 PERIODIC MAINTENANCE............................................... 3-1
1. CONSUMABLE PARTS.............................................................................................3-1
1.1 Toner Cartridge................................................................................................................ 3-1
1.2 Drum Unit ......................................................................................................................... 3-7
2. PERIODICAL REPLACEMENT PARTS ..................................................................3-12
2.1 Periodical Replacement Parts ....................................................................................... 3-12
2.2 Procedures to Replace Periodical Replacement Parts.................................................. 3-13
2.2.1 Fuser unit and laser unit.................................................................................................... 3-13
2.2.2 Paper feeding kit for tray 1, 2, 3 ........................................................................................ 3-35
2.2.3 Paper feeding kit for MP tray............................................................................................. 3-43