Brother IntelliFax-3550 User manual

FACSIMILE EQUIPMENT
SERVICE MANUAL
MODEL: FAX[phone]P/8200P
MFC4450/4550/4550plus
MFC6550MC/7550MC/7650MC
MFC9000/9500

© Copyright Brother 1998
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.

PREFACE
This publication is a Service Manual covering the specifications, construction, theory of opera-
tion, and maintenance of the Brother facsimile equipment. It includes information required for
field troubleshooting and repair—disassembly, reassembly, and adjustment—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 six chapters and appendices.
CHAPTER I. GENERAL DESCRIPTION
CHAPTER II. INSTALLATION
CHAPTER III. THEORY OF OPERATION
CHAPTER IV. DISASSEMBLY/REASSEMBLY AND LUBRICATION
CHAPTER V. MAINTENANCE MODE
CHAPTER VI. ERROR INDICATION AND TROUBLESHOOTING
APPENDICES Circuit Diagrams
This manual describes the model and its versions to be destined for major countries. The specifications
and functions are subject to change depending upon each destination.

SAFETY INFORMATION
Laser Safety (110 - 120V Model only)
This printer is certified as a Class 1 laser product under the US Department of Health and Human
Services (DHHS) Radiation Performance Standard according to the Radiation Control for Health
and Safety Act of 1968. This means that the printer does not produce hazardous laser radiation.
Since radiation emitted inside the printer is completely confined within the protective housings and
external covers, the laser beam cannot escape from the machine during any phase of user opera-
tion.
CDRH Regulations (110 - 120V Model only)
The Center for Device and Radiological Health (CDRH) of the US Food and Drug Administration
implemented regulations for laser products on August 2, 1976. These regulations apply to laser
products manufactured fromAugust 1, 1976. Compliance is mandatory for products marketed in the
UnitedStates. ThelabelshownbelowindicatescompliancewiththeCDRHregulationsandmustbe
attached to laser products marketed in the United States.
The label for Japanese products
MANUFACTURED: AUGUST 1998 K
BROTHER INDUSTRIES, LTD.
15-1 Naeshiro-cho Mizuho-ku Nagoya 467-8561, Japan.
This product complies with FDA radiation
performance standards, 21 CFR Subchapter J.

CHAPTER I.
GENERAL DESCRIPTION

CONTENTS
1. EQUIPMENT OUTLINE................................................................................. I-1
1.1External Appearance and Weight........................................................... I-1
1.2Components............................................................................................I-1
2. SPECIFICATIONS..........................................................................................I-2

I – 1
1. EQUIPMENT OUTLINE
1.1 External Appearance and Weight
The figure below shows the equipment appearance and approximate dimensions.
251 (H)
452 (D)
383 (W)
(excluding the handset) (Unit: mm)
Weight: Machine proper Approx. 8.5 kg (excluding the drum unit and toner cartridge)
In package Approx. 13.5 kg (FAX[phone]P/8200P)
Approx. 14 kg (MFC4450/4550/4550plus/6550MC/7550MC/
7650MC/9000/9500)
1.2 Components
The equipment consists of the following major components:
Top cover
High-voltage power
supply ASSY
Relay PCB
Main PCB
NCU PCB ASSY
Scanner frame ASSY
Main cover
Control panel ASSY
Heat-fixing unit
Inner cover
Multi-purpose
sheet feeder
Drum unit with toner
cartridge loaded
Laser unit
Handset
Gear drive unit
Low-voltage power
supply ASSY
Bottom plate

I – 2
2. SPECIFICATIONS
MODEL FAX3550 MFC4550 MFC6550MC MFC7550MC
COLOR 1267 1138 1138 1138
PRINTER Option
Engine — HL-720 HL-730 HL-730
PPM — 6 6 6
dpi — 600 x 600 600 x 600 600 x 600
Paper Capacity 200 200 200 200
Standards — Windows GDI (600x600) Windows GDI (600x600) Windows GDI (600x600)
Emulation — No PCL4 (300x300) PCL4 (300x300)
Memory (Typical) — 512 KB 512 KB 1 MB
Memory (Min.) — 300 KB 400 KB 1 MB
Fonts Resident — No 24-bit map (PCL4 Comp) 24-bit map (PCL4 Comp)
Fonts Disk Based — No Yes Yes
Paper Handling LTR, LGL, A4 LTR, LGL, EXE, A4, B5,A5 LTR, LGL, EXE, A4, B5, A5 LTR, LGL, EXE, A4, B5,A5
Multi-purpose Sheet Custom Size (2.85x5-8x14) Custom Size (2.85x5-8x14) Custom Size (2.85x5-8x14) Custom Size (2.85x5-8x14)
Feeder Envelope (BL/C5/COM 10/Mona) Envelope (BL/C5/COM 10/Mona) Envelope (BL/C5/COM 10/Mona) Envelope (BL/C5/COM 10/Mona)
Printer Driver — Windows 3.1, 95 Driver with Windows 3.1, 95 Driver with Windows 3.1, 95 Driver with
Auto Installer Program Auto Installer Program Auto Installer Program
Toner Life (5%/page) 2200 pages 2200 pages 2200 pages 2200 pages
Utility Software — — RPC RPC
SCANNER Option
Color/Mono — Mono Mono Mono
Gray Scale — 64 256 256
dpi — 400 x 400 600 x 600 600 x 600
Twain — Yes Yes Yes
ADF Capacity (pages) (30) 30 30 30
Formats — TIFF/BMP (by M/L) TIFF/BMP (by M/L) TIFF/BMP (by M/L)
OCR — Option Yes Yes
COPY
dpi 200 x 400 200 x 400 600 class 600 class
No. of Copies 1-99 1-99 1-99 1-99
Sorting No No Yes Yes
Reduction/Enlargement 50-200% 50-200% 50-200% 50-200%
FAX
Modem ROCKWELL V12 ROCKWELL V12 ROCKWELL V24 ROCKWELL V24
Modem Speed 14400 bps (FAX only) 14400 bps (FAX only) 14400 bps (FAX only) 14400 bps (FAX only)
CCITT Group G3 G3 G3 G3
Coding Method MH/MR/MMR MH/MR/MMR MH/MR/MMR MH/MR/MMR
Transmission Speed 6 sec. 6 sec. 6 sec. 6 sec.
Input/Output Width 8.5"/8.5" 8.5"/8.5" 8.5"/8.5" 8.5"/8.5"
LCD Size 16 x 1 16 x 2 16 x 2 16 x 2
Super Fine Yes (Send only) Yes (Send only) Yes (Send only) Yes
Gray Scale 64 64 64 64
Smoothing Yes Yes Yes Yes
Handset Yes Yes Yes Yes
One-touch Dial 20 x 2 12 x 2 12 x 2 12 x 2
Speed Dial 100 36 36 100
Telephone Index Yes Yes Yes Yes
Contrast Super L/Auto/Super D Super L/Auto/Super D Super L/Auto/Super D Super L/Auto/Super D
Multi-resolution Transmission Yes Yes Yes Yes
FAX/TEL Switch Yes Yes Yes Yes
Distinctive Ringing Yes Yes Yes Yes
Caller ID Yes Yes Yes Yes
Next FAX-reservation Yes Yes Yes Yes
Help Yes Yes Yes Yes
TAD Interface Yes Yes Yes Yes
(1/2)

I – 3
MODEL FAX3650 MFC4450 MFC4550plus MFC7650MC
COLOR 1267 1138 1138 1138
PRINTER Option
Engine — HL-720 HL-720 HL-730
PPM — 6 6 6
dpi 200 x 200 600 x 600 600 x 600 600 x 600
Paper Capacity 200 200 200 200
Standards Windows GDI (200x200) Windows GDI (600x600) Windows GDI (600x600) Windows GDI (600x600)
Emulation — No PCL4 (300x300) PCL4 (300x300)
Memory (Typical) — 512 KB 512 KB 1 MB
Memory (Min.) — 300 KB 400 KB 600 KB
Fonts Resident — No 24-bit map (PCL4 Comp) 24-bit map (PCL4 Comp)
Fonts Disk Based — No Yes Yes
Paper Handling LTR, LGL,A4 LTR, LGL,A4, B5,A5 LTR, LGL, A4, B5, A5 LTR, LGL,A4, B5,A5
Multi-purpose Sheet — Custom Size (2.85x5-8x14) Custom Size (2.85x5-8x14) Custom Size (2.85x5-8x14)
Feeder Envelope (BL/C5/COM 10/Mona) Envelope (BL/C5/COM 10/Mona) Envelope (BL/C5/COM 10/Mona)
Printer Driver — Windows 3.1, 95 Driver with Windows 3.1, 95 Driver with Windows 3.1, 95 Driver with
Auto Installer Program Auto Installer Program Auto Installer Program
Toner Life (5%/page) 2200 pages 2200 pages 2200 pages 2200 pages
Utility Software — — RPC RPC
SCANNER Option
Color/Mono — Mono Mono Mono
Gray Scale — 64 64 256
dpi — 400 x 400 400 x 400 600 x 600
Twain — Yes Yes Yes
ADF Capacity (pages) — 30 30 30
Formats (Import) —
TIFF/BMP/PCX/DCX/BTF/BTX/UNI TIFF/BMP/PCX/DCX/BTF/BTX/MAX TIFF/BMP/PCX/DCX/BTF/BTX/MAX
Formats (Export) — TIFF/BMP/UNI TIFF/BMP/MAX TIFF/BMP/MAX
OCR — Option Yes Yes
COPY
dpi 200 x 400 200 x 400 200 x 400 600 class
No. of Copies 1-99 1-99 1-99 1-99
Sorting Yes No No Yes
Reduction/Enlargement 50-200% 50-200% 50-200% 50-200%
FAX
Modem ROCKWELL V12 Toshiba ROCKWELL V12 ROCKWELL V24
Modem Speed 14400 bps (FAX only) 9600 bps (FAX only) 14400 bps (FAX only) 14400 bps (FAX only)
CCITT Group G3 G3 G3 G3
Coding Method MH/MR/MMR MH/MR/MMR MH/MR/MMR MH/MR/MMR
Transmission Speed 6 sec. 9 sec. 6 sec. 6 sec.
Input/Output Width 8.5"/8.5" 8.5"/8.5" 8.5"/8.5" 8.5"/8.5"
LCD Size 16 x 1 16 x 2 16 x 2 16 x 2
Super Fine Yes Yes Yes Yes
Gray Scale 64 64 64 64
Smoothing Yes Yes Yes Yes
Handset Yes No Yes Yes
One-touch Dial 20 x 2 12 x 2 12 x 2 12 x 2
Speed Dial 100 36 36 100
Telephone Index Yes Yes Yes Yes
Contrast Super L/Auto/Super D Super L/Auto/Super D Super L/Auto/Super D Super L/Auto/Super D
Multi-resolution Transmission Yes Yes Yes Yes
FAX/TEL Switch Yes Yes (with External) Yes Yes
Distinctive Ringing Yes Yes (with External) Yes Yes
Caller ID Yes No Yes Yes
Next FAX-reservation Yes Yes Yes Yes
Help Yes Yes Yes Yes
TAD Interface Yes Yes Yes Yes
(1/2)

I – 4
MODEL FAX8000P MFC9000 MFC9500 FAX8200P
COLOR 1138 1138 1138 1138
PRINTER Option Option
Engine — HL-730 HL-730 —
PPM — 6 6 —
dpi —
600 x 600 (GDI) / 300 x 300 (PCL4) 600 x 600 (GDI) / 300 x 300 (PCL4) —
Paper Capacity 200 200 200 200
Standards — Windows GDI Windows GDI —
Emulation — PCL4 PCL4 —
Memory (Typical) — 512 KB 512 KB —
Memory (Min.) — 400 KB 400 KB —
Fonts Resident — 24-bit map (PCL4 Comp) 24-bit map (PCL4 Comp) —
Fonts Disk Based — Yes Yes —
Paper Handling A4, B5, A5 A4, B5, A5 A4, B5, A5 A4
Multi-purpose Tray
Custom Size (73x127-126x350 mm) Custom Size (73x127-216x350 mm) Custom Size (73x127-216x350 mm)
—
Envelope (DL/C5/COM 10/Mona) Envelope (DL/C5/COM 10/Mona) Envelope (DL/C5/COM 10/Mona)
Printer Driver — Windows 3.1, 95 Driver with Windows 3.1, 95 Driver with —
Auto Installer Program Auto Installer Program
Mac Driver (Option) Mac Driver (Option)
Toner Life (5%/page) 2200 pages 2200 pages 2200 pages 2200 pages
Utility Software —
Remote Priter Console (RPC) Remote Printer Console (RPC) —
SCANNER Option Option
Color/Mono — Mono Mono —
Gray Scale — 256 256 —
dpi — 600 x 600 600 x 600 —
Twain — Yes Yes —
ADF Capacity (pages) 30 30 30 —
Formats — TIFF/BMP TIFF/BMP —
OCR — Option Yes —
COPY
dpi 200 x 400 300 x 400 300 x 400 200 x 400
No. of Copies 1-99 1-99 1-99 1-99
Sorting
Available with optional memory Yes Yes Yes
Reduction/Enlargement 50-200% 50-200% 50-200% 50-200%
FAX
Modem ROCKWELL V12 ROCKWELL V12 ROCKWELL V24 ROCKWELL V12
Modem Speed 14400 bps (FAX only) 14400 bps (FAX only) 14400 bps (FAX only) 14400 bps (FAX only)
CCITT Group G3 G3 G3 G3
Coding Method MH/MR/MMR MH/MR/MMR MH/MR/MMR MH/MR/MMR
Transmission Speed 6 sec. 6 sec. 6 sec. 6 sec.
Input/Output Width 8.5"/8.5" 8.5"/8.5" 8.5"/8.5" 8.5"/8.5"
LCD Size 16 x 1 16 x 2 (STN) 16 x 2 (STN) 16 x 1
Super Fine (Send) Yes Yes Yes Yes
Super Fine (Receive)
Available with optional memory Available with optional memory Available with optional memory Yes
Gray Scale 64 64 64 64
Smoothing Yes Yes Yes Yes
Handset No No No No
One-touch Dial 20 x 2 12 x 2 12 x 2 20 x 2
Speed Dial 100 100 100 100
Telephone Index Yes Yes Yes Yes
Contrast Light/Auto/Dark Light/Auto/Dark Light/Auto/Dark Light/Auto/Dark
Multi-resolution Transmission Yes Yes Yes Yes
FAX/TEL Switch Yes Yes Yes Yes
Distinctive Ringing Yes Yes Yes —
Caller ID
Yes (U.K., Sweden, Holland and France) Yes (U.K., Sweden, Holland and France) Yes (U.K., Sweden, Holland and France) Yes (U.K., Sweden, Holland and France)
Next FAX-reservation Yes Yes Yes Yes
Help Yes Yes Yes Yes
TAD Interface Yes Yes Yes Yes
(1/2)

I – 5
MODEL FAX3550 MFC4550 MFC6550MC MFC7550MC
FAX
Coverpage Yes, Super Yes, Super Yes, Super Yes, Super
Polling Type Std/Del/Seq Std/Del/Seq Std/Del/Seq Std/Del/Seq
Receive password Yes Yes Yes Yes
Delayed Transmission Yes, 3 timings Yes, 3 timings Yes, 3 timings Yes, 3 timings
Call Reservation Yes Yes Yes Yes
Callback Message Yes Yes Yes Yes
Page Memory (TX)* 300 KB (30 pgs: MMR) 200 KB (20 pgs: MMR) 300 KB (30 pgs: MMR) 700 KB (70 pgs: MMR)
Out-of-paper Reception* 400 KB (40 pgs: MMR) 400 KB (40 pgs: MMR) 600 KB (60 pgs: MMR) 1.5 MB (150 pgs: MMR)
Super Quick Scan Yes Yes Yes Yes
Auto Reduction Yes Yes Yes Yes
ECM Yes Yes Yes Yes
Broadcasting Yes Yes Yes Yes
Multi Transmission Yes Yes Yes Yes
MESSAGE CENTER
TAD Feature No No Yes (Hardware & PC) Yes (Hardware & PC)
ICM Recording Time No No Hardware: 15 min. Hardware: 30 min.
Paging No No Yes (Hardware & PC) Yes (Hardware & PC)
Toll Saver No No Yes (Hardware & PC) Yes (Hardware & PC)
OGM No No Yes (Hardware & PC) Yes (Hardware & PC)
Mail Box No No Yes (PC only) Yes (PC only)
Fax-on-demand No No Yes (PC only) Yes (PC only)
Voice-on-demand No No Yes (PC only) Yes (PC only)
FAX Forwarding Yes Yes Yes Yes
FAX Retrieval Yes Yes Yes Yes
MACHINE MEMORY 0.75 MB 0.75 MB 1 MB 2 MB
OPTIONAL MEMORY 1 or 2 MB 1 or 2 MB 1 or 2 MB 1 or 2 MB
(FAX & PRINTER FLEX)
PC FAX (Send/Receive) Option Yes (by M/L) Yes (by M/L) Yes (by M/L)
Standard — Class 1, 2 Class 1, 2 Class 1, 2
DATA MODEM No No No No
INTERFACE
Printer Interface —
Centronics parallel (w/o cable) Centronics parallel (w/o cable) Centronics parallel (w/o cable)
MULTI-FUNCTION LINK PRO MULTI-FUNCTION LINK PRO MULTI-FUNCTION LINK PRO
PC Interface RS-232C ———
(8-pin modular connector)
MULTI-FUNCTION LINK
Extended I/O Interface — — RS-232C and RS-422 RS-232C and RS-422
(supported by an optional serial (supported by an optional serial
interface board RS-100M) interface board RS-100M)
Simultaneous
Sends FAX and Prints — Yes Yes Yes
Receives FAX and Prints — Yes Yes Yes
Receives FAX and Scans — Yes Yes Yes
Prints and Scans — Yes Yes Yes
Receives FAX and Copies — Yes Yes Yes
Prints and Copies — Yes Yes Yes
* CCITT#1 Chart in the Standard Mode, MMR
(2/2)

I – 6
MODEL FAX3650 MFC4450 MFC4550plus MFC7650MC
FAX
Coverpage Yes, Super Yes, Super Yes, Super Yes, Super
Polling Type Std/Del/Seq Std/Del/Seq Std/Del/Seq Std/Del/Seq
Delayed Transmission Yes, 13 timings Yes, 3 timings Yes, 3 timings Yes, 13 timings
Call Reservation Yes Yes (with External) Yes Yes
Callback Message Yes Yes Yes Yes
Page Memory (TX)* 1 MB (100 pgs: MMR) 300 KB (30 pgs: MMR) 300 KB (30 pgs: MMR) 800 KB (80 pgs: MMR)
Out-of-paper Reception* 1.1 MB (110 pgs: MMR) 600 KB (60 pgs: MMR) 600 KB (60 pgs: MMR) 1.0 MB (100 pgs: MMR)
Super Quick Scan Yes Yes Yes Yes
ECM Yes Yes Yes Yes
Broadcasting Yes Yes Yes Yes
Multi Transmission No Yes Yes No
MESSAGE CENTER
ICM Recording Time No No No Hardware: 30 min.
Paging Yes (Hardware & PC) Yes (Hardware & PC) Yes (Hardware & PC) Yes (Hardware & PC)
Toll Saver No No No Yes (Hardware & PC)
OGM No No No Yes (Hardware & PC)
Mail Box No No Yes (PC only) Yes (PC only)
Fax-on-demand No No No Yes (PC only)
Voice-on-demand No No No Yes (PC only)
FAX Forwarding Yes Yes Yes Yes
FAX Retrieval Yes Yes Yes Yes
MACHINE MEMORY 2 MB 1 MB 1 MB 2 MB
OPTIONAL MEMORY 1 or 2 MB No 1 or 2 MB 1 or 2 MB
(FAX & PRINTER FLEX)
PC FAX (Send/Receive) Option Yes (by M/L) Yes (by M/L) Yes (by M/L)
Standard — SMSI SMSI SMSI
DATA MODEM No No No No
INTERFACE
Printer Interface —
Centronics parallel (w/o cable) Centronics parallel (w/o cable) Centronics parallel (w/o cable)
MULTI-FUNCTION LINK PRO MULTI-FUNCTION LINK PRO MULTI-FUNCTION LINK PRO
PC Interface RS-232C ———
(8-pin modular connector)
MULTI-FUNCTION LINK
Extended I/O Interface — — — RS-232C and RS-422
(supported by an optional serial
interface board RS-100M)
Simultaneous
Sends FAX and Prints — Yes Yes Yes
Receives FAX and Prints — Yes Yes Yes
Receives FAX and Scans — Yes Yes Yes
Prints and Scans — Yes Yes Yes
Receives FAX and Copies — Yes Yes Yes
Prints and Copies — Yes Yes Yes
* CCITT#1 Chart in the Standard Mode, MMR
(2/2)

I – 7
MODEL FAX8000P MFC9000 MFC9500 FAX8200P
FAX
Coverpage Yes, Super Yes, Super Yes, Super Yes, Super
Polling Type Std/Del/Seq/Sec Std/Del/Seq/Sec Std/Del/Seq/Sec Std/Del/Seq/Sec
Receive password Yes/Plus Yes/Plus Yes/Plus Yes/Plus
Delayed Transmission Yes, 3 timings Yes, 3 timings Yes, 3 timings Yes, 3 timings
Call Reservation Yes Yes Yes Yes
Callback Message Yes Yes Yes Yes
Page Memory (TX)* 300 KB (30 pgs: MMR) 300 KB (30 pgs: MMR) 300 KB (30 pgs: MMR) 1 MB (100 pgs: MMR)
Out-of-paper Reception* 400 KB (40 pgs: MMR) 600 KB (40 pgs: MMR) 600 KB (60 pgs: MMR) 1.1 MB (110 pgs: MMR)
Super Quick Scan Yes Yes Yes Yes
Auto Reduction Yes Yes Yes Yes
ECM Yes Yes Yes Yes
Broadcasting Up to 140 destinations Up to 124 destinations Up to 124 destinations Up to 190 destinations
Multi Transmission Yes Yes Yes Yes
MESSAGE CENTER
TAD Feature No No Yes (Hardware & PC) No
ICM Recording Time No No Hardware: 15 min. No
Paging No No Yes (Hardware & PC) No
Toll Saver No No Yes (Hardware & PC) No
OGM UK/SWISS/AUS/GER UK/SWISS Yes (Hardware & PC) UK/SWISS/GER
Mail Box No No Yes (PC only) No
Fax-on-demand No No Yes (PC only) No
Voice-on-demand No No Yes (PC only) No
FAX Forwarding Yes Yes Yes Yes
FAX Retrieval Yes Yes Yes Yes
MACHINE MEMORY 0.75 MB 1 MB 1 MB 2 MB
OPTIONAL MEMORY 1 or 2 MB 1 or 2 MB 1 or 2 MB 1 or 2 MB
(FAX & PRINTER FLEX)
PC FAX (Send/Receive) Option Yes Yes Option
Standard — Class 2 Class 2 —
DATA MODEM No No No No
INTERFACE
Printer Interface —
Centronics parallel (w/o cable) Centronics parallel (w/o cable) —
MULTI-FUNCTION LINK PRO MULTI-FUNCTION LINK PRO
PC Interface RS-232C ——
RS-232C
(8-pin modular connector) (8-pin modular connector)
CONNECT 5000 INTERFACE CONNECT 5000 INTERFACE
Extended I/O Interface — RS-232C and RS-422 RS-232C and RS-422 —
(supported by an optional serial (supported by an optional serial
interface board RS-100M) interface board RS-100M)
Simultaneous
Sends FAX and Prints — Yes Yes —
Receives FAX and Prints —YesYes—
Receives FAX and Scans —YesYes—
Prints and Scans — Yes Yes —
Receives FAX and Copies —YesYes—
Prints and Copies — Yes Yes —
* CCITT#1 Chart in the Standard Mode, MMR
(2/2)

CHAPTER II.
INSTALLATION

CONTENTS
1. INSTALLING THE UPDATE DATA TO THE FACSIMILE EQUIPMENT...............II-1

II - 1
1. INSTALLING THE UPDATE DATA TO THE
FACSIMILE EQUIPMENT
If the program version is updated or the main PCB is replaced, install the update program onto the
flash ROM of the main PCB.
The program installation requires a host computer satisfying the following requirements:
- CPU Pentium 75 or higher
- RAM 8MB or greater (16MB recommended for Windows95)
- OS Windows3.1/3.11 or Windows95
Connecting the equipment to your computer
(1) Make sure that the equipment's power cord is unplugged from a wall socket.
(2) Make sure that your computer is powered off.
(3) Connect the interface cable to the parallel interface port on the back of the equipment and
secure it with the lock wires.
(4) Connect the other end of the interface cable to the printer port of your computer and secure
it with the two screws.
(5) Power on your computer.
(6) Plug the equipment's power cord into a wall socket.
Host computer
Interface cable
Lock
wires

II - 2
Installing the update data onto the flash ROM of the facsimile equipment
(1) Load the floppy disk which stores the update data and transfer utility into the floppy disk
drive of your computer.
(Or, copy the update data and transfer utility onto the same directory of the hard disk.)
(2) Click the Start button, point to Programs, and then click MS-DOS Prompt to open an MS-
DOS window.
(3) Type the drive letter where the update data and transfer utility are located. If it is a floppy
disk drive, type A:\ from the command line and press the ENTER key.
(4) Check that your computer is connected with the facsimile equipment correctly.
(5) To start the transfer utility transmitting the update data to the flash ROM of the facsimile
equipment, type the following:
A:\ICEN filename /b
Then press the ENTER key.
The equipment beeps and shows the "CONNECTING" on the LCD for one second.
Then, the equipment shows the "DOWNLOADING" on the LCD and starts receiving data
downloaded from the host computer.
During downloading, the equipment beeps intermittently.
Upon completion of the downloading, the equipment beeps continuously.

CHAPTER III.
THEORY OF OPERATION

CONTENTS
1. OVERVIEW.....................................................................................................III-1
2. MECHANISMS................................................................................................III-2
2.1Scanner Mechanism.............................................................................. III-3
2.1.1Document feeding and ejecting mechanism................................... III-3
2.1.2Document scanning mechanism..................................................... III-3
2.2Laser Printing Mechanism...................................................................... III-4
2.2.1Paper pulling-in, registration, feeding, and ejecting mechanism..... III-4
2.2.2Print process mechanism................................................................ III-6
(1) Charging process.................................................................... III-7
(2) Exposing process.................................................................... III-7
(3) Developing process................................................................. III-8
(4) Transferring process................................................................ III-8
(5) Erasing process....................................................................... III-8
2.2.3Heat-fixing mechanism................................................................... III-9
2.3Sensors and Actuators........................................................................... III-10
3. CONTROL ELECTRONICS........................................................................... III-12
3.1Configuration...........................................................................................III-12
3.2Main PCB................................................................................................III-13
3.3Relay PCB..............................................................................................III-23
3.4NCU PCB................................................................................................III-24
3.5Control Panel PCB................................................................................. III-27
3.6Power Supply PCBs............................................................................... III-28
[ 1 ]Low-voltage power supply PCB.................................................. III-28
[ 2 ]High-voltage power supply PCB................................................. III-29

III – 1
1. OVERVIEW
Fax Control Section Laser Printing Control Section
PC/AT MAC
RS-232C RS-422
NCU
Handset
Line Speaker
Fax data
Printer
data
AC
Control
panel
Scanner unit Paper
feeding
mechanism
Low- and
high-voltage
power
supplies
Laser printing unit
RS-232C
(Modular connector) Centronics
parallel interface Optional serial interface
(Extended I/O connector)
[MFC6550MC/7550MC/
7650MC/9000/9500]
[FAX[phone]/
8000P/8200P] [MFC4450/
4550/4550plus/
6550MC/7550MC/7650MC/
9000/9500]
- LED array
- CCD unit
- Scanner motor Charging, exposing,
developing,
transferring, erasing,
and heat-fixing
processes
- Electrical charger
- Laser unit
(including the polygon
motor)
- Laser-sensitive drum
- Developer roller
- Transfer roller
- Eraser lamp
- Heater roller
- Main motor