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Brother International DCP 8040 Service Manual - Page 228

Insufficient output from high-voltage power supply unit, Fixing heater temperature failure, Laser

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MFC-8440/8840D/8840DN, DCP-8040/8045D/8045DN SERVICE MANUAL M-5 Insufficient output from high-voltage power supply unit Possible cause High-voltage contact High-voltage power supply PCB Step 1 2 Check Do any of the terminals on the high-voltage contacts have dirt or contact burns? Check the connections of the connector between the highvoltage power supply and the engine PCB are secured correctly. Result Remedy Yes Clean the terminals. Yes Replace the high-voltage power supply PCB No Reconnect the connector between the high-voltage power supply and the engine PCB. M-6 Fixing heater temperature failure Possible cause Poor thermistor harness contact Blown thermal fuse Thermistor failure Halogen heater lamp failure Step 1 2 3 4 Check Is the contact of connector CN7 on the engine PCB good? Remove the fixing unit and measure the resistance of the thermal fuse. Is it open circuit? Is the thermistor installed properly? Remove the fixing unit and measure the resistance of the halogen heater lamp. Is it open circuit? Result No Yes Yes No Yes Remedy Reconnect the connector. Replace the fixing unit. Replace the fixing unit. Reinstall the thermistor properly. Replace the halogen heater lamp. M-7 Laser Unit failure Possible cause Harness connection failure (1) Harness connection failure (2) Step 1 Check Is the LD harness connector on the main PCB secured correctly? 2 Is the polygon motor connector on the engine PCB secured correctly? Result No Remedy Reconnect the connector securely. Yes Replace the laser unit. No Reconnect the connector securely. Yes Replace the laser unit. 6-25

Section	Page
MFC8440/8840D/8840DN DCP8040/8045D/8045DN SERVICE MANUAL	1
PREFACE	3
TABLE OF CONTENTS	4
REGULATION	10
SAFETY INFORMATION	12
CHAPTER 1 GENERAL	14
1. OVERVIEW	14
2. SPECIFICATIONS	16
2.1General	16
2.2General (Continued)	16
2.3Print Media	17
2.4Copy	17
2.5Fax	18
2.6Scanner	19
2.7Printer	19
2.8Interfaces	20
2.9Consumable Items	20
2.10Network (LAN) Board (NC-9100h)	20
2.11Computer Requirements	21
2.12Paper	22
2.12.1Type and size of paper	22
2.12.2Recommended paper	22
2.12.3Paper capacity of the paper trays	22
2.12.4Paper specifications for each paper tray	23
2.13Printable Area	24
2.13.1PCL5e/EPSON/IBM emulation	24
2.13.2PCL6/BR-Script3 emulation	27
2.14Print Speeds with Various Settings	28
2.15Toner Cartridge Weight Information	28
3. SERIAL NO. DESCRIPTIONS	29
CHAPTER 2 INSTALLATION AND BASIC OPERATION	31
1. CONDITIONS REQUIRED FOR INSTALLATION	31
1.1Power Supply	31
1.2Environment	31
2. UNPACKING	32
3. INSTALL THE MACHINE	33
3.1For All Users	33
3.1.1Install the Automatic Document Feed (ADF) support	34
3.1.2Install the drum unit assembly	35
3.1.3Load paper into the paper tray	36
3.1.4Release the scanner lock	37
3.2Installing the Driver & Software	38
3.2.1For USB Interface Cable Users (For WindowsR 98/98SE/Me/20...	38
3.2.2For Parallel Interface Cable Users (For WindowsR 95/98/98...	43
3.2.3For Windows NTR Workstation Version 4.0 Users	48
3.2.4For Network Interface Cable Users (For WindowsR 95/98/98S...	50
3.2.5For USB Interface Cable Users (For MacR OS 8.6 to 9.2 Use...	53
3.2.6For USB Interface Cable Users (For MacR OS X 10.1/10.2.1 ...	54
3.2.7For Network Interface Cable Users (For MacR OS 8.6 to 9.2...	55
3.2.8For Network Interface Cable Users (For MacR OS X 10.1/10....	56
CHAPTER 3 THEORY OF OPERATION	57
1. ELECTRONICS	57
1.1General Block Diagram	57
1.2Main PCB Block Diagram	58
1.3Main PCB	59
1.3.1CPU	59
1.3.2USB	59
1.3.3IEEE1284	60
1.3.4ROM	60
1.3.5Flash ROM	61
1.3.6SDRAM	61
1.3.7Optional RAM	62
1.3.8EEPROM	63
1.3.9Reset circuit	63
1.3.10Engine I/O	63
1.3.11Panel I/O	63
1.3.12Video I/O	64
1.3.13Scanner control	64
1.3.14Power supply	65
1.4Engine PCB	66
1.5Power Supply	67
1.5.1Low-voltage power supply	67
1.5.2High-voltage power supply	68
2. MECHANICS	69
2.1Overview of Printing Mechanism	69
2.2Scanner Mechanism	70
2.3Paper Transfer	71
2.3.1Paper supply	71
2.3.2Paper registration	71
2.3.3Paper eject	72
2.3.4Duplex printing	72
2.4Sensors	73
2.4.1Cover sensors	73
2.4.2Toner sensors	73
2.4.3Cassette sensor / Paper empty sensor	74
2.4.4Paper eject sensor	74
2.4.5MP-PE sensor	75
2.4.6Document cover sensor	75
2.4.7Document front sensor /Document rear sensor	76
2.4.8DX-sensor PCB ASSY	76
2.4.9Rear cover sensor	77
2.4.10HP sensor	77
2.5Drum Unit	78
2.5.1Photosensitive drum	78
2.5.2Primary charger	78
2.5.3Transfer roller	78
2.5.4Cleaner	78
2.6Toner Cartridge	78
2.7Print Process	78
2.7.1Charging	78
2.7.2Exposure stage	79
2.7.3Developing	80
2.7.4Transfer	80
2.7.5Fixing stage	81
CHAPTER 4 DISASSEMBLY AND RE-ASSEMBLY	82
1. SAFETY PRECAUTIONS	82
2. DISASSEMBLY FLOW	83
3. DISASSEMBLY PROCEDURE	84
3.1AC Cord	84
3.2Drum Unit	84
3.3Paper Tray	85
3.4DX Feed ASSY (MFC-8840D/8840DN, DCP-8045D/8045DN only)	95
3.5Access Cover / Battery	98
3.6Driver PCB Access Cover	99
3.7ADF Unit	100
3.8Document Scanner	109
3.9Panel Unit	114
3.10Rear Cover C (MFC-8440, DCP-8040 only)	117
3.11Outer Chute (MFC-8440, DCP-8040 only)	118
3.12Rear Cover MP ASSY / Outer Chute MP ASSY(MFC-8840D/8840DN, DCP-8045D/8045DN only)	119
3.13Rear Cover L/R	120
3.14Side Cover L/R	121
3.15Joint Cover	122
3.16Front Cover ASSY (MFC-8440, DCP-8040 only)	126
3.17MP Unit (MFC-8840D/8840DN, DCP-8045D/8045DN only)	127
3.18Rear Cover Sensor	132
3.19NCU (MFC-8440/8840D/8840DN only)	133
3.20Fixing Unit	134
3.21Laser Unit	143
3.22Main PCB	145
3.23Base Plate / LV Insulation Sheet	147
3.24DX-Sensor PCB ASSY (MFC-8840D/8840DN, DCP-8045D/8045DN only)	148
3.25Engine PCB	149
3.26High-voltage PS PCB ASSY	150
3.27Low-voltage PS PCB ASSY	151
3.28Paper Feeder	152
3.29Frame L / Drive Unit	159
3.30Reversing Release Solenoid (MFC-8840D/8840DN, DCP-8045D/8045DN only)	163
3.31Thermistor ASSY	164
3.32Fan Motor 60 Unit LV / Fan Motor 60 Unit	164
3.33Frame R	165
4. PACKING	167
5. GUIDELINES FOR LEAD FREE SOLDER	168
6. SCREW TORQUE LIST	171
7. LUBRICATION	173
8. HARNESS ROUTING	178
CHAPTER 5 PERIODIC MAINTENANCE	180
1. CONSUMABLE PARTS	180
1.1Drum Unit	180
1.2Toner Cartridge	182
2. PERIODICAL REPLACEMENT PARTS	186
2.1Fixing Unit	187
2.2Paper Feeding Kit	195
3. PERIODICAL CLEANING	199
3.1Cleaning the Machine Exterior	199
3.2Cleaning the Scanner	199
3.3Cleaning the Printer	200
3.4Cleaning the Drum Unit	201
3.5Cleaning the Scanner Window	201
3.6Cleaning the Electrical Terminals	202
4. MTBF / MTTR	203
CHAPTER 6 TROUBLESHOOTING	204
1. INTRODUCTION	204
1.1Initial Check	204
1.2Warnings for Maintenance Work	205
1.3Identify the Problem	206
2. ERROR MESSAGE	207
2.1Error Message on the LCD	207
2.2Error Codes Shown in the “MACHINE ERROR X X” message.	210
3. PAPER PROBLEMS	214
3.1Paper Loading Problems	214
3.2Original Jams	215
3.2.1Original is jammed in the top of the ADF unit	215
3.2.2Original is jammed inside the ADF unit	215
3.3Paper Jams	216
3.3.1Clearing jammed paper	216
3.3.2Paper is jammed in the Duplex Tray (For MFC-8840D/8840DN,...	219
3.3.3Causes & countermeasures	220
3.4Paper Feeding Problems	221
4. SOFTWARE SETTING PROBLEMS	223
5. MALFUNCTIONS	226
6. TROUBLESHOOTING OF THE CONTROL PANEL	231
7. TROUBLESHOOTING OF FAX FUNCTIONS	233
8. IMAGE DEFECTS	237
8.1Image Defect Examples	237
8.2Diameter of Rollers	237
8.3Troubleshooting Image Defect	238
8.4Location of Grounding Contacts	256
8.4.1Drum unit	256
8.4.2Machine body & Paper tray	256
9. INCORRECT PRINTOUT	257
10. NETWORK PROBLEM	259
10.1Installation Problem	259
10.2Intermittent Problem	260
10.3TCP/IP Troubleshooting	261
10.4UNIX Troubleshooting	261
10.5WindowsR NT/LAN Server (TCP/IP) Troubleshooting	262
10.6WindowsR 95/98/Me Peer to Peer Print (LPR) Troubleshooting	262
10.7WindowsR 95/98/Me Peer to Peer (HP JetAdmin Compatible Met...	262
10.8WindowsR 95/98/Me/2000/XP/NT 4.0 Peer to Peer Print (NetBI...	263
10.9Brother Internet Print (TCP/IP) Troubleshooting	263
10.10WindowsR 95/98/Me/2000/XP IPP Troubleshooting	263
10.11Novell Netware Troubleshooting	264
10.12AppleTalk Troubleshooting	265
10.13DLC/LLC Troubleshooting	265
10.14Web Browser Troubleshooting (TCP/IP)	265
10.15Internet Fax Troubleshooting	266
CHAPTER 7 MAINTENANCE MODE	267
1. ENTRY INTO THE MAINTENANCE MODE	267
2. LIST OF MAINTENANCE-MODE FUNCTIONS	268
3. DETAILED DESCRIPTION OF MAINTENANCE-MODE FUNCTIONS	270
3.1EEPROM Parameter Initialization (Maintenance mode 01/91)	270
3.2Printout of Scanning Compensation Data (Maintenance mode 05)	271
3.3Placement of CCD Unit in Position for Transportation (Maintenance mode 06)	273
3.4ADF Performance Test (Maintenance mode 08)	273
3.5Test Pattern 1 (Maintenance mode 09)	274
3.6Firmware Switch Setting and Printout	275
3.6.1Firmware switch setting (Maintenance mode 10)	275
3.6.2Printout of firmware switch data (Maintenance mode 11)	277
3.7Operation Check of LCD (Maintenance mode 12)	278
3.8Operational Check of Control Panel PCB (Maintenance mode 13)	279
3.9Sensor Operational Check (Maintenance mode 32)	280
3.10Received Data Transfer Function (Maintenance mode 53)(MFC-8440/8840D/8840DN only)	282
3.11Fine Adjustment of Scan Start/End Positions (Maintenance mode 54)	284
3.12CCD Scanner Area Setting (Maintenance mode 55)	286
3.13EEPROM Customizing (Maintenance mode 74)	287
3.14Printing out of Machine Log Information (Maintenance mode 77)	288
3.15Display of the Equipment’s Log Information (Maintenance mode 80)	290
3.16Machine Error Code Indication (Maintenance mode 82)	292
3.17Output of Transmission Log to the Telephone Line (Maintenace mode 87)	292
3.18Cancellation of the Memory Security Mode (Not applicable to the Japanese version)	293
APPENDIX 1 EEPROM CUSTOMIZING CODES	294
APPENDIX 2 INSTALLING THE UPDATE DATA	296
1. INSTALLING THE UPDATE DATA TO THE MACHINE	296
1.1Connecting the Machine to Your PC	296
1.2Setting up the Machine and Your PC	296
1.3Installing the Update Data onto the Flash ROM of the Machine	297
2. SETTING ID CODES TO MACHINES	298
2.1Connecting the Machine to Your PC	298
2.2Setting Up the Machine and Your PC	298
2.3Running the Setup Utility	299
APPENDIX 3 FIRMWARE SWITCHS (WSW)	300
APPENDIX 4 CIRCUIT DIAGRAMS	361

Match case Limit results 1 per page

MFC-8440/8840D/8840DN, DCP-8040/8045D/8045DN

SERVICE MANUAL

6-25

M-5

Insufficient output from high-voltage power supply unit

Possible cause

Step

Check

Result

Remedy

High-voltage

contact

Do any of the terminals on the

high-voltage contacts have dirt

or contact burns?

Yes

Clean the terminals.

High-voltage

power supply

PCB

Check the connections of the

connector between the high-

voltage power supply and the

engine PCB are secured

correctly.

Yes

Replace the high-voltage

power supply PCB

Reconnect the connector

between the high-voltage

power supply and the engine

PCB.

M-6

Fixing heater temperature failure

Possible cause

Step

Check

Result

Remedy

Poor thermistor

harness contact

Is the contact of connector

CN7 on the engine PCB good?

Reconnect the connector.

Blown thermal

fuse

Remove the fixing unit and

measure the resistance of the

thermal fuse.

Is it open circuit?

Yes

Replace the fixing unit.

Thermistor

failure

Is the thermistor installed

properly?

Yes

Replace the fixing unit.

Reinstall the thermistor

properly.

Halogen heater

lamp failure

Remove the fixing unit and

measure the resistance of the

halogen heater lamp.

Is it

open circuit?

Yes

Replace the halogen heater

lamp.

M-7

Laser Unit failure

Possible cause

Step

Check

Result

Remedy

Harness

connection

failure (1)

Is the LD harness connector

on the main PCB secured

correctly?

Reconnect the connector

securely.

Yes

Replace the laser unit.

Harness

connection

failure (2)

Is the polygon motor connector

on the engine PCB secured

correctly?

Reconnect the connector

securely.

Yes

Replace the laser unit.