Brother FAX100 User manual

FACSIMILE EQUIPMENT
SERVICE MANUAL
MODEL: FAX[phone]/675
FAX575M/715M/725M
FAX590DT/590MC/825MC/875MC

© Copyright Brother 1995
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 five chapters and appendices.
CHAPTER I . GENERAL DESCRIPTION
CHAPTER II . INSTALLATION
CHAPTER III. THEORY OF OPERATION
CHAPTER IV. INDICATION AND INFORMATION PRINTOUT OF ERROR
CHAPTER V. MAINTENANCE
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.

CHAPTER I.
GENERAL DESCRIPTION

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

I – 1
1. EQUIPMENT OUTLINE
1.1 External Appearance
The figure below shows the equipment appearance and approximate dimensions.
(Unit: mm)
Main PCB
NCU PCB
Control Panel PCB
Recording Head Unit
LED Array (for illuminating documents)
Charge Coupled Device (CCD) Unit
Sensors
Power Supply PCB
Recorder & Cutter Unit
CCD Unit
Drive Motor
(for paper & document feed and for cutter drive)
Clutch Solenoid
Drive Gears
Control Panel Unit
Covers
Automatic Document Feeder (ADF)
Handset
Frame and Miscellaneous Parts
Electronic/
Electrical/
Section
Mechanical
Section
Facsimile
Equipment
Package
Accessories
1.2 Components
The equipment has the following components:
121 (H)
304 (D)
377 (W)

I – 2
Model FAX100 FAX615 FAX625 FAX635 FAX675
Color 1138 BN4 BN2 BN4 BN2
Modem Speed 9600 bps 9600 bps 9600 bps 9600 bps 9600 bps
Coding Method MH MH MH MH MH
Transmission Speed 15 sec 15 sec 15 sec 15 sec 15 sec
CCITT Group G3 G3 G3 G3 G3
Input/Output Width 8.5"/8.5" 8.5"/8.5" 8.5"/8.5" 8.5"/8.5" 8.5"/8.5"
Auto Cutter Yes Yes Yes Yes Yes
ADF Capacity (pages) 15 15 15 15 15
Anti-curl System Yes Yes Yes Yes Yes
Paper Size (Standard thermal/Therma PLUS) 164'/164' 164'/164' 164'/164' 164'/164' 164'/164'
LCD Size 16 x 1 16 x 1 16 x 1 16 x 1 16 x 1
On-screen Programming Yes Yes Yes Yes Yes
Super Fine Yes Yes Yes Yes Yes
Smoothing Yes Yes Yes Yes Yes
Gray Scale 32 32 32 64 64
One-touch Dialing 10x2 10 10x2 10x2 10x2
Speed Dialing 20 30 20 30 40
Group Dialing No No No No No
Telephone Index No No No No No
Speakerphone Monitor Monitor Monitor Monitor Monitor
Fax/Tel Switch Yes Yes Yes Yes Yes
TAD Interface Yes Yes Yes Yes Yes
Enhanced Remote Activation Yes Yes Yes Yes Yes
Distinctive Ringing Yes Yes Yes Yes Yes
Next-Fax Reservation Yes No Yes Yes Yes
Help Yes Yes Yes Yes Yes
Caller ID No No No No Yes
Automatic Redialing Yes Yes Yes Yes Yes
Multi-Resolution Transmission Yes Yes Yes Yes Yes
Polling Std/Sec/Del Std/Sec/Del Std/Sec/Del Std/Sec/Del Std/Sec/Del
Delayed Transmission Yes, 1 timer Yes, 1 timer Yes, 1 timer Yes, 1 timer Yes, 1 timer
Coverpage Yes Yes Yes Yes Yes
Call Reservation Yes Yes Yes Yes Yes
Call Back Message Yes Yes Yes Yes Yes
Activity Report Yes Yes Yes Yes Yes
Transmission Verification Report Yes Yes Yes Yes Yes
Page Memory No No No No No
ECM No No No No No
Broadcasting No No No No No
Quick Scanning No No No No No
Out-of-Paper Reception No No No No No
Multi Copy No No No No No
Multi Transmission No No No No No
TAD Type No No No No No
ICM Recording Time No No No No No
Remote Control No No No No No
Paging No No No No No
Toll Saver No No No No No
Memo/2-Way Recording No No No No No
Time/Date Stamp No No No No No
Message Center No No No No No
2. SPECIFICATIONS
(Note 1) No: Asia and Taiwan
Option*: Gulf, China, and Saudi Arabia
OGM No No No No No
FAX Forwarding No No No No No
FAX Retrieval No No No No No
PCI (Missing link) (* : w/o PC FAX RX) No (Note 1) (Note 1) Option* Option*
Password No No No No No
Paper Save No No No No No
Day-Night Mode No No No No No
Elec. Vol. Control No No No No No
FAX-on-demand No No No No No
Voice-on-demand No No No No No
Fax Mail Box No No No No No
Voice Mail Box No No No No No

I – 3
Model FAX715M FAX725M FAX825MC FAX875MC
Color BN2 BN4 BN2 BN2
Modem Speed 9600 bps 14400 bps 14400 bps 14400 bps
Coding Method MH MH MH MH
Transmission Speed 15 sec 9 sec 9 sec 9 sec
CCITT Group G3 G3 G3 G3
Input/Output Width 8.5"/8.5" 8.5"/8.5" 8.5"/8.5" 8.5"/8.5"
Auto Cutter Yes Yes Yes Yes
ADF Capacity (pages) 15 15 15 15
Anti-curl System Yes Yes Yes Yes
Paper Size (Standard thermal/Therma PLUS) 164'/164' 164'/164' 164'/164' 164'/164'
LCD Size 16 x 1 16 x 1 16 x 1 16 x 1
On-screen Programming Yes Yes Yes Yes
Super Fine Yes Yes Yes Yes
Smoothing Yes Yes Yes Yes
Gray Scale 64 64 64 64
One-touch Dialing 10x2 10x2 10x2 10x2
Speed Dialing 40 40 40 80
Group Dialing 6 6 6 6
Telephone Index Yes Yes Yes Yes
Speakerphone Monitor Monitor Monitor Monitor
Fax/Tel Switch Yes Yes Yes Yes
TAD Interface Yes Yes Yes Yes
Enhanced Remote Activation Yes Yes Yes Yes
Distinctive Ringing Yes (Note 2) Yes (Note 3)
Next-Fax Reservation Yes Yes Yes Yes
Help Yes Yes Yes Yes
Caller ID Yes (Note 2) Yes (Note 3)
Automatic Redialing Yes Yes Yes Yes
Multi-Resolution Transmission Yes Yes Yes Yes
Polling Std/Sec/Del Std/Sec/Del Std/Sec/Del/Seq Std/Sec/Del/Seq
Delayed Transmission Yes, 3 timers Yes, 3 timers Yes, 3 timers Yes, 3 timers
Coverpage Yes Yes Yes Yes
Call Reservation Yes Yes Yes Yes
Call Back Message Yes Yes Yes Yes
Activity Report Yes Yes Yes Yes
Transmission Verification Report Yes Yes Yes Yes
Page Memory 10 pages 10 pages 50 pages 50 pages
ECM Yes Yes Yes Yes
Broadcasting Yes Yes Yes Yes
Quick Scanning Yes Yes Yes Yes
Out-of-Paper Reception Yes Yes Yes Yes
Multi Copy Yes, w/sort Yes, w/sort Yes, w/sort Yes, w/sort
Multi Transmission Yes Yes Yes Yes
TAD Type No No IC Digital IC Digital
ICM Recording Time No No (18 min) (18 min)
Remote Control No No Full Full
Paging No No Yes Yes
Toll Saver No No Yes Yes
Memo/2-Way Recording No No Yes Yes
Time/Date Stamp No No Yes Yes
Message Center No No Yes Yes
OGM No No Yes Yes
FAX Forwarding No No Yes Yes
FAX Retrieval No No Yes Yes
PCI (Missing link) (* : w/o PC FAX RX) Option Option Option Option
Password No No No No
Paper Save No No No No
Day-Night Mode No No No No
Elec. Vol. Control No No No No
FAX-on-demand Yes Yes
Voice-on-demand No No Yes Yes
Fax Mail Box No No Yes, 5 Yes, 5
Voice Mail Box No No Yes, 5 Yes, 5
(Note 2) No: Taiwan
Yes: Other countries
(Note 3) No: Asia, Gulf, China, and Saudi Arabia
Yes: Other countries

I – 4
Smoothing Yes Yes Yes
Gray Scale 32 64 64
One-touch Dialing 10x2 10x2 10x2
Speed Dialing 40 40 40
Group Dialing None 6 6
Telephone Index No Yes Yes
Speakerphone No No No
Fax/Tel Switch Yes Yes Yes
TAD Interface Yes Yes Yes
Enhanced Remote Activation Yes Yes Yes
Next-Fax Reservation Yes Yes Yes
Help Yes Yes Yes
Caller ID UK/Holland/Sweden UK UK/Holland/Sweden
Automatic Redialing Yes Yes Yes
Multi-Resolution Transmission Yes Yes Yes
Polling Std/Sec/Del Std/Sec/Del Std/Sec/Del/Seq
Delayed Transmission Yes, 1 timer Yes, 3 timers Yes, 3 timers
Coverpage Yes Yes Yes
Call Reservation Yes Yes Yes
Call Back Message Yes Yes Yes
Journal Report (Activity Report) Yes Yes Yes
Transmission Verification Report Yes Yes Yes
Page Memory (Brother chart) No 10 pages 55 pages
(CCITT No. 1 chart) No 9 pages 49 pages
ECM No Yes Yes
Broadcasting No 60 60
Quick Scanning No No No
Out-of-Paper Reception No Yes Yes
Multi Copy No Yes, w/stack & sort Yes, w/stack & sort
Multi Transmission No Yes Yes
TAD Type No No IC Digital
ICM Recording Time No No 13 min
Remote Control No No Yes
Paging No No Yes
Toll Saver No No Yes
Time/Date Stamp No No Yes
Message Center No No Yes
OGM No No Yes
FAX Forwarding No No Yes
FAX Retrieval No No Yes
(Note 4) 1293: German and UK versions
1138: Other versions
Backup for Voice No No 6 hours
Backup for Page Memory No No 6 hours
Backup for Clock 15 hours 15 hours 15 hours
Fax Mail Box No No Yes, 5
Voice Mail Box No No Yes, 5
CCITT Group G3 G3 G3
Input/Output Width A4/A4 A4/A4 A4/A4
Auto Cutter Yes Yes Yes
ADF Capacity (pages) 15 15 15
Anti-curl System Yes Yes Yes
Model FAX570 FAX575M FAX590DT/590MC
Color 1138/1293 (Note 4) 1138/1293 (Note 4) 1138/1293 (Note 4)
Modem Speed 9600 bps 9600 bps 14400 bps
Coding Method MH MH MH
Transmission Speed (Brother chart) 15 sec 13 sec 9 sec
(ITU-T No. 1 chart) 19 sec 15 sec 10 sec
Paper Size (Standard thermal/Therma PLUS) 50 m/50 m 50 m/50 m 50 m/50 m
LCD Size 16 x 1 16 x 1 16 x 1
On-screen Programming Yes Yes Yes
Super Fine Yes Yes Yes
Connect 5000 Connectivity No Yes Yes
(PCI or Missing link) (* : w/o PC FAX RX)
Password No No No
FAX-on-demand No No Up to 50 messages
Voice-on-demand No No Up to 50 messages

CHAPTER II.
INSTALLATION

CHAPTER III.
THEORY OF OPERATION

CONTENTS
1. OVERVIEW.....................................................................................................III-1
1.1Mechanical Layout................................................................................. III-1
1.2Functional Block Diagram...................................................................... III-1
2. MECHANISMS................................................................................................III-2
2.1Transmitting Mechanism (Feeding and Scanning Documents).............. III-2
2.1.1Automatic document feeder (ADF).................................................. III-2
2.1.2Scanner...........................................................................................III-2
2.2Receiving Mechanism (Feeding Recording Paper & Recording Data)... III-3
2.2.1Anti-curl system (ACS).................................................................... III-3
2.2.2Automatic cutter.............................................................................. III-3
2.3Sensors...................................................................................................III-4
2.4Power Transmission Shift by the Planetary Gear Train and
Clutch Solenoid.......................................................................................III-6
2.4.1Description of planetary gear train.................................................. III-6
2.4.2Power transmission for four operation modes................................. III-7
[ 1 ]Recording mode (Solenoid: OFF, Motor rotation: Forward)........ III-7
[ 2 ]Scanning mode (Solenoid: OFF, Motor rotation: Reverse).......... III-8
[ 3 ]Copying mode (Solenoid: ON ➞OFF, Motor rotation: Forward).III-8
[ 4 ]Cutter driving mode (Solenoid: ON, Motor rotation: Reverse)..... III-9
2.4.3Power transmission route............................................................... III-10
3. CONTROL ELECTRONICS........................................................................... III-11
3.1Configuration...........................................................................................III-11
3.2Main PCB................................................................................................III-11
3.2.1FAX[phone]/675/575M/715M.................................... III-12
[ 1 ]Primary function group................................................................ III-12
[ 2 ]ROM and DRAM group............................................................... III-13
[ 3 ]Image processing group............................................................. III-14
[ 4 ]Analog signal processing group.................................................. III-15
3.2.2FAX725M/590DT/590MC/825MC/875MC....................................... III-16
[ 1 ]Primary function group................................................................ III-16
[ 2 ]DRAM group............................................................................... III-17

[ 3 ]Image processing group............................................................. III-18
[ 4 ]Analog signal processing group.................................................. III-19
[ 5 ]MODEM.......................................................................................III-20
3.3NCU PCB................................................................................................III-21
3.4Control Panel PCB................................................................................. III-23
3.5Power Supply..........................................................................................III-24

III – 1
1. OVERVIEW
1.1 Mechanical Layout
Recorder & cutter unit
Recording paper cover
Drive unit
Handset
Handset mount Main PCB
NCU PCB
Bottom plate
Power supply PCB
Scanner frame ASSY
Main frame
Panel cover ASSY
PCI
(Missing link)
LCD
Control panel
Scanner
Line NCU
Telephone Speaker
Drive unit
Power supply
Recorder
Automatic
cutter
PC
Controller
1.2 Functional Block Diagram

III – 2
2. MECHANISMS
2.1 Transmitting Mechanism (Feeding and Scanning Documents)
The transmitting mechanism consists of the document stacker, automatic document feeder
(ADF), document feeding related rollers, scanner, and document sensors. (For details about
the sensors, refer to Section 2.3.)
If the operator sets documents on the stacker and starts the sending operation, the ADF
feeds those documents into the equipment, page by page. Each document advances with
the separation roller to the scanner, and then it is fed out of the equipment with the LF roller.
For the drive power source, refer to Section 2.4.
,,,,,,
,,,,,,
,,,,,,
,,,,
,,,,
,,,,,, ,,,,,, ,,,,,, ,,,,,, ,,,,,, ,,,,,, ,,,,,,
,,, ,,, ,,,
, ,
,,
,,
,,
,, ,, ,, ,, ,,
Separation roller ASSY
Pressure roller (Front)
LF roller ASSY
Document Roller (mounted on
the panel rear cover)
2.1.1 Automatic document feeder (ADF)
The ADF, which consists of the separation roller and separator, feeds documents set on the
document stacker, starting from the bottom sheet to the top, page by page, due to the fric-
tional difference among the separation roller, the documents, and the separator.
2.1.2 Scanner
The scanner uses a charge coupled device (CCD) image sensor.
As shown below, the LED array illuminates a document and the reflected light of the scanned
image data is transmitted via the mirrors into the lens which reduces the scanned data so as
to form the image on the CCD.
,,, ,,, ,,, ,,, ,,, ,,, ,,,
,,, ,,,
,, ,,
,, ,,
,
,
,,,, ,,,, ,,,,
,, ,, ,, ,,
,,,, ,,,, ,,,, ,,,,
,,, ,,,
, ,
,,,, ,,,,
Mirror
CCD PCB
Mirrors LED array
(Front)
Lens
Bar lens
Separation roller ASSY

III – 3
2.2 Receiving Mechanism (Feeding Recording Paper & Recording Data)
The receiving mechanism consists of the recording paper roll holder, anti-curl system (ACS),
platen, thermal recording head, automatic cutter, and sensors. (For details about the sen-
sors, refer to Section 2.3.)
The recording paper is routed through the ACS to the recording head which prints onto the
heat-sensitive recording paper pressed by the platen according to received image signals.
The printed paper is further fed through the cutter chute and cut by the automatic cutter page
by page.
For the drive power source, refer to Section 2.4.
2.2.1 Anti-curl system (ACS)
The ACS eliminates curl peculiar to the rolled recording paper by curving the paper towards
the opposite side of the curl with theACS rod and the ACS plate.
2.2.2 Automatic cutter
The automatic paper cutter consists of an upper blade (rotary) and a lower blade (station-
ary). As the upper blade rotates around the left end as a support, the recording paper will be
cut. Upon completion of cutting operation, the upper blade returns to the home position
which is detected by the cutter sensor.
,,,
,,,
,,,
,
,
,,
Recording paper roll
ACS plate
Recording
head
Lower blade
Upper blade
Cutter chute
Platen
ACS rod
(Rear)

III – 4
2.3 Sensors
This equipment has two photosensors and four mechanical sensors as described below.
Photosensors
• Document front sensor which detects a presence of documents.
• Document rear sensor which detects the leading and trailing edges of pages to tell the
control circuitry when the leading edge of a new page has reached the starting position
and when the scan for that page is over.
These two photosensors are located on the main PCB. They are of a reflection type consist-
ing of a light-emitting diode and a light-receiving transistor. Each of them has an actuator
separately arranged (see the next page). If an actuator is activated, its white end will come
to the path of light issued from the light-emitting diode and reflect its light. The moment the
reflected light enters the light-receiving transistor, the sensor signals the detection.
Mechanical sensors
• PE (paper empty) sensor which detects whether the recording paper is present.
• Cover sensor which detects whether the recording paper cover is closed.
• Cutter sensor which detects the home position of the upper rotary blade of the automatic
cutter.
• Hook switch sensor which detects whether the handset is placed on the handset mount.
These four sensors are located on the NCU PCB. Each of them has an actuator separately
arranged (see the next page). If an actuator is activated, its lower end pushes down the le-
ver provided on the corresponding sensor so that the sensor signals the detection.
Power supply PCB
PH1 PH2
NCU PCB
(Rear)
SW1
SW2
SW3
SW4
Main PCB
Approx.
0.7 mm
Path of
actuator's end
Glass
Light-
emitting
diode
Light-
receiving
transistor
Document rear sensor
Document front sensor
PE sensor
Cover sensor
Hook switch
sensor
Cutter sensor

III – 5
(Front)
,,
Document rear sensor actuator
Document front
sensor actuator
PE sensor
actuator
(Front)
Hook switch
sensor actuator
Drive unit
Cover sensor actuator
Cutter sensor
actuator
Location of Sensor Actuators

III – 6
2.4 Power Transmission Shift by the Planetary Gear Train and Clutch Solenoid
The equipment has a single drive motor whose power transmission route can be switched by
the planetary gear train and the clutch solenoid. Accordingly, the equipment mechanism can
function in four operation modes (recording, scanning, copying, and cutter driving modes).
2.4.1 Description of planetary gear train
The planetary gear train consists of the sun gear 18/73, two planet gears 20, arm A, and arm
B, as shown below.
Planet gear 20A
Sun gear 18/73
Arm B
Planet gear 20B
Arm A
Sun gear 18/73
Motor gear
Arm A Planet gear 20A
Stopper of arm A
Arm B
Planet gear 20B
If the motor rotates, the sun gear 18/73 rotates so that the rotational force is transmitted to
the engagement between the sun gear and the planet gears 20. Since the arms and planet
gears are so designed that the moment of the arms is less than that of the planet gears, the
arms turn around the center shaft in the same direction as the sun gear 18/73.
If the planet gear(s) becomes engaged with any other gear so that the arm cannot turn fur-
thermore, the rotational force of the sun gear 18/73 is transmitted to that planet gear. Ac-
cordingly, the planet gear starts rotation in the opposite direction of the sun gear 18/73.

III – 7
2.4.2 Power transmission for four operation modes
Depending upon the clutch solenoid ON/OFF state and the motor rotation direction, the plan-
etary gear train switches the power transmission route for the four operation modes.
Clutch lever
Solenoid
Solenoid: ON
Solenoid: OFF
Sun gear 18/73 Arm B
Planet gear
20B
Stopper of arm A
Planet gear 20A
Arm A
Forward
Reverse
A(Motor gear) C2 (Planet
gear 20A)
Clutch
solenoid
C1 (Planet gear 20B)
D
E(Platen gear)
[ 1 ] Recording mode (Solenoid: OFF, Motor rotation: Forward)
In the recording mode, the control system deactivates the clutch solenoid (see the above fig-
ure, Solenoid: OFF). Therefore, when the motor rotates in the forward direction, the clutch
lever turns clockwise with the spring and its cutout Xbecomes engaged with the stopper of
arm A. Once arm A is locked, the planet gear 20A (C2) will not be engaged with any other
gear but simply idle.
The motor rotation turns the sun gear 18/73 (B) counterclockwise so that the planet gear 20B
(C1) transmits the rotation to the platen gear (E) via the gear D.
F
Section Y
Cutout X
Section Y
Cutout X
Spring
(engaged
with stopper
of arm A)
Cutout X of
clutch lever
B(Sun gear
18/73)
(Front)
Motor gear