Brother MFC-4820C User manual

FACSIMILE EQUIPMENT
SERVICE MANUAL
MODEL: MFC4820C/MFC4420C

© Copyright Brother 2003
All rights reserved.
No part of this publication may be reproduced in any
form or by any means without permission in writing
from the publisher.
Specifications are subject to change without notice.

i
PREFACE
This publication is a Service Manual covering the specifications, construction, theory of operation,
and maintenance of the Brother facsimile equipment. It includes information required for field
troubleshooting and repair--disassembly, reassembly, and lubrication--so that service personnel
will be able to understand equipment function, to rapidly repair the equipment and order any
necessary spare parts.
To perform appropriate maintenance so that the facsimile equipment is always in best condition
for the customer, the service personnel must adequately understand and apply this manual.
This manual is made up of eight chapters and appendices.
SAFETY INSTRUCTIONS
CHAPTER 1 PARTS NAMES & FUNCTIONS
CHAPTER 2 SPECIFICATIONS
CHAPTER 3 SETTING UP OF THE MACHINE
CHAPTER 4 THEORY OF OPERATION
CHAPTER 5 ROUTINE MAINTENANCE
CHAPTER 6 DISASSEMBLY/REASSEMBLY
CHAPTER 7 MAINTENANCE MODE
CHAPTER 8 TROUBLESHOOTING
Appendix 1. Serial No. Descriptions
Appendix 2. Software Installation
Appendix 3. EEPROM Customizing Codes
Appendix 4. Firmware Switches (WSW)
Appendix 5. Re-packing Instructions
Appendix 6. Wiring Diagram
Appendix 7. Circuit Diagrams
This manual describes the models and their versions to be destined for major countries. The specifications
and functions are subject to change depending upon each destination.

ii
SAFETY PRECAUTIONS
To Use the Machine Safely
Save these instructions for later reference.
There are high voltage electrodes inside the
machine. Before you clean the machine or
clear a paper jam, make sure you have
unplugged the power cord from the power
outlet.
Do not handle the plug with wet hands.
Doing this might cause an electrical shock.
To prevent injuries, be careful not to put
your hands on the edge of the machine
under the scanner cover.
To prevent injuries, be careful not to put
your fingers in the area shown in the
illustration.
Use caution when installing or modifying telephone lines. Never touch telephone wires or terminals that
are not insulated unless the telephone line has been disconnected at the wall jack. Never install telephone
wiring during a lightning storm. Never install a telephone jack in a wet location unless the jack is
specifically designed for a wet location.
Install equipment with a power cord near a socket-outlet that is easily accessible.
To reduce the risk of shock or fire, use only a No. 26 AWG or larger telecommunication line cord.
Do not use a telephone in the vicinity of gas leak to report leak.

iii
Lightning and power surges can damage this product! We recommend that you use a quality surge
protection device on the AC power line and on the telephone line, or unplug the lines during a lightning
storm.
Do not use this product near appliances that use water, in a wet basement or near a swimming pool.
Avoid using a telephone other than a cordless type during an electrical storm. There may be a remote risk
of electric shock from lightning.
Choosing a Location
Place your machine on a flat, stable surface that is free of vibration and shocks, such as a desk. Put the
machine near a telephone jack and a standard, grounded power outlet. Choose a location where the
temperature remains between 50°F and 95°F (10° and 35°C).
Avoid placing your machine in a high-traffic area.
Do not place near heaters, air conditioners, water, chemicals, or refrigerators.
Do not expose the machine to direct sunlight, excessive heat, moisture, or dust.
Do not connect your machine to electrical outlets controlled by wall switches or automatic timers.
Disruption of power can wipe out information in the machine’s memory.
Do not connect your machine to electrical outlets on the same circuit as large appliances or other
Equipment that might disrupt the power supply.
Avoid interference sources, such as speakers or the base units of cordless phones.

CHAPTER 1
PARTS NAMES & FUNCTIONS

CHAPTER 1 PARTS NAMES & FUNCTIONS
CONTENTS
1.1 EQUIPMENT OUTLINE ...................................................................................................1-1
1.2 CONTROL PANEL...........................................................................................................1-3
1.3 COMPONENTS................................................................................................................1-5

1-1
1.1 EQUIPMENT OUTLINE
Front view
(6) Paper support
(5) Paper tray
(4) Paper guide
(3) PhotoCapture™ media slot
(2) Output paper support
(1) Output paper support extension
(10) Control panel
(9) Scanner cover release lever
(8) Scanner cover
(7) Document cover
Rear view
(13) USB interface connector
(12) Telephone line jack
(11) External telephone line jack

1-2
No. Name Description
(1) Output paper support extension Pull it out to prevent the printed paper from falling.
(2) Output paper support
Printed paper comes out here.
(3) PhotoCapture™ media slot Insert your media card into the appropriate slot to print a digital
photo.
(4) Paper guide Press and slide it to fit the paper width.
(5) Paper tray Load paper here.
(6) Paper support Unfold to support paper.
(7) Document cover Open to place the original on the scanner glass.
(8) Scanner cover Open to install an ink cartridge or to remove jammed paper.
(9) Scanner cover release lever Pull to open the scanner cover.
(10) Control panel Use the keys and display to control the machine.
(11) External telephone line jack Plug in the modular plug on the external telephone line here.
(12) Telephone line jack Plug in the modular plug on the telephone line here.
(13) USB interface connector Connect the USB cable here.

1-3
1.2 CONTROL PANEL
A. Telephone and Message Center keys B. Liquid Crystal Display (LCD)
On/Off
Let’s you activate the Message Center and blinks if
you did not play your voice messages.
Play/Record
Lets you listen to voice messages stored in memory.
Also, it lets you record telephone calls.
Erase
Lets you delete voice messages, all fax messages or
all messages.
Speaker Phone
Lets you dial telephone and fax numbers and speak to
another party without lifting the handset.
Hold
Lets you place calls on hold.
Redial/Pause
Redials the last number you called. It also inserts a
pause in auto dial numbers.
Displays messages on the screen to help you set up
and use your machine.
Quality
Date Current receive
mode
Recording paper
type
A
BEDC