Brother Fax875MC, Fax825MC, Fax590MC, Fax590DT, Fax725M Service Manual

...
FACSIMILE EQUIPMENT
SERVICE MANUAL
MODEL: FAX100/570/615/625/635/675
FAX575M/715M/725M FAX590DT/590MC/825MC/875MC
© Copyright Brother 1995 All rights reserved. No part of this publication may be reproduced in any
Specifications are subject to change without notice.

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 adjustment—so that service personnel will be able to understand equipment function, to rapidly repair the equipment and order any necessary spare parts.
T o 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 CHAPTER II CHAPTER III. THEORY OF OPERATION CHAPTER IV. INDICATION AND INFORMATION PRINTOUT OF ERROR CHAPTER V. MAINTENANCE
APPENDICES Circuit Diagrams
.
GENERAL DESCRIPTION
.
INSTALLATION
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
1. EQUIPMENT OUTLINE
1.1 External Appearance
The figure below shows the equipment appearance and approximate dimensions.
121 (H)
1.2 Components
The equipment has the following components:
Facsimile Equipment
377 (W)
Electronic/ Electrical/ Section
Mechanical Section
304 (D)
(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 Clutch Solenoid
(for paper & document feed and for cutter drive)
Package Accessories
Drive Gears Control Panel Unit Covers Automatic Document Feeder (ADF) Handset Frame and Miscellaneous Parts
I – 1
2. SPECIFICATIONS
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 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 Y es 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 T ype 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 OGM No No No No No FAX Forwarding No No No No No FAX Retrieval No No No No No PCI (Missing link) 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
(Standard thermal/Therma PLUS)
(* : w/o PC FAX RX)
164'/164' 164'/164' 164'/164' 164'/164' 164'/164'
No (Note 1) (Note 1) Option* Option*
(Note 1) No: Asia and Taiwan
Option*: Gulf, China, and Saudi Arabia
I – 2
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 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) 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
(Standard thermal/Therma PLUS)
(* : w/o PC FAX RX)
164'/164' 164'/164' 164'/164' 164'/164'
Option Option Option Option
(Note 2) No: Taiwan
Yes: Other countries
(Note 3) No: Asia, Gulf, China, and Saudi Arabia
Yes: Other countries
I – 3
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 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
Paper Size LCD Size 16 x 1 16 x 1 16 x 1 On-screen Programming Yes Yes Yes Super Fine Yes Yes Yes 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
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
Connect 5000 Connectivity (PCI or Missing link)
Backup for Voice No No 6 hours Backup for Page Memory No No 6 hours Backup for Clock 15 hours 15 hours 15 hours Password No No No FAX-on-demand No No Up to 50 messages Voice-on-demand No No Up to 50 messages
Fax Mail Box No No Yes, 5 Voice Mail Box No No Yes, 5
(Standard thermal/Therma PLUS)
(Brother chart) (ITU-T No. 1 chart)
(CCITT No. 1 chart) No 9 pages 49 pages
(* : w/o PC FAX RX)
15 sec 13 sec 9 sec 19 sec 15 sec 10 sec
50 m/50 m 50 m/50 m 50 m/50 m
No Yes Yes
(Note 4) 1293: German and UK versions
1138: Other versions
I – 4
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
3.2.1FAX100/570/615/625/635/675/575M/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
1. OVERVIEW
1.1 Mechanical Layout
Recording paper cover
Recorder & cutter unit
Drive unit
Handset
Panel cover ASSY
Main frame
Scanner frame ASSY
Handset mount
Main PCB
1.2 Functional Block Diagram
LCD
Control panel
Scanner
NCU PCB
(Missing link)
PCI
Power supply PCB
Bottom plate
PC
Automatic
cutter
Recorder
Line NCU
Telephone
Controller
Drive unit
Power supply
Speaker
III – 1
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.
Roller (mounted on
Document
Separation roller ASSY
the panel rear cover)
LF roller ASSY
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 fric­tional 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.
Lens
Pressure roller
Separation roller ASSY
(Front)
Bar lens
CCD PCB
Mirror
(Front)
Mirrors LED array
III – 2
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 sen­sors, 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.
Upper blade
Lower blade
(Rear)
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 the ACS rod and the ACS plate.
Cutter chute
Platen
Recording head
ACS rod
ACS plate
Recording paper roll
2.2.2 Automatic cutter
The automatic paper cutter consists of an upper blade (rotary) and a lower blade (station­ary). 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.
III – 3
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 consist­ing 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 le­ver provided on the corresponding sensor so that the sensor signals the detection.
(Rear)
NCU PCB
Cutter sensor Hook switch
sensor Cover sensor
SW3 SW4
SW2
PH1 PH2
Main PCB
SW1
PE sensor
Approx.
0.7 mm
Power supply PCB
Path of actuator's end
Glass
Document rear sensor
Document front sensor
III – 4
Light­emitting diode
Light­receiving transistor
PE sensor actuator
Document front sensor actuator
(Front)
Document rear sensor actuator
Drive unit
Cutter sensor actuator
(Front)
Cover sensor actuator
Hook switch sensor actuator
Location of Sensor Actuators
III – 5
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.
Arm B
Sun gear 18/73
Arm A
Planet gear 20B
Sun gear 18/73
Motor gear
Arm A
Planet gear 20A
Planet gear 20A
Planet gear 20B
Arm B
Stopper of arm A
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 fur­thermore, the rotational force of the sun gear 18/73 is transmitted to that planet gear. Ac­cordingly, the planet gear starts rotation in the opposite direction of the sun gear 18/73.
III – 6
2.4.2 Power transmission for four operation modes
Depending upon the clutch solenoid ON/OFF state and the motor rotation direction, the plan­etary gear train switches the power transmission route for the four operation modes.
Section Y Cutout X
Clutch lever
Section Y Cutout X
(engaged with stopper of arm A)
[ 1 ] Recording mode (Solenoid: OFF, Motor rotation: Forward)
Solenoid: ON
Solenoid: OFF
Spring
Solenoid
Motor gear
Arm A
Sun gear 18/73
Arm B
Planet gear 20B
Stopper of arm A
Planet gear 20A
Forward Reverse
In the recording mode, the control system deactivates the clutch solenoid (see the above fig­ure, Solenoid: OFF). Therefore, when the motor rotates in the forward direction, the clutch lever turns clockwise with the spring and its cutout X becomes 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.
B (Sun gear
18/73)
E (Platen gear)
A (Motor gear)
C1 (Planet gear 20B)
D
F
Cutout X of clutch lever
C2 (Planet
gear 20A)
(Front)
Clutch solenoid
III – 7
[ 2 ] Scanning mode (Solenoid: OFF, Motor rotation: Reverse)
Just as in the recording mode, the control system deactivates the clutch solenoid in the scanning mode to lock arm A.
The motor rotates in the reverse direction and the sun gear 18/73 (B) rotates clockwise so that the planet gear 20A (C2) transmits the rotation to the separation roller gear (L) and LF roller gear (O) via the several gears.
C2 (Planet
gear 20A)
I
B (Sun gear
18/73)
A (Motor gear)
[ 3 ] Copying mode (Solenoid: ON OFF, Motor rotation: Forward)
F
Cutout X of clutch lever
H
J
G
Clutch solenoid
K
L (Separation
roller gear)
M
(Front)
N
O (LF roller
gear)
The control system at first activates the clutch solenoid to release the stopper of arm A from coutout X of the clutch lever while rotating the motor in the forward direction. Accordingly, the sun gear 18/73 (B) rotates counterclockwise so that both the planet gears 20B (C1) and 20A (C2) transmit the rotation to the platen gear (E) and the roller gears (separation roller gear and LF roller gear), respectively.
Once the planet gear 20A becomes engaged with the gear P, the control system deactivates the clutch solenoid.
B (Sun gear
18/73)
A (Motor gear)
E (Platen gear)
C2 (Planet gear 20A)
C1 (Planet gear 20B)
D
H
G
F
P
Clutch lever
I
III – 8
K
J
L (Separation
roller gear)
M
(Front)
N
O (LF roller
gear)
[ 4 ] Cutter driving mode (Solenoid: ON, Motor rotation: Reverse)
B (Sun gear
18/73)
Q (Cutter
gear)
The control system activates the clutch solenoid to release the stopper of arm A from cutout X of the clutch lever. When the motor rotates in the reverse direction, the sun gear 18/73 (B) rotates clockwise so that the planet gear 20A (C2) transmits the rotation to the cutter gear (Q).
Since the planet gear 20B (C1) is blocked by section Y of the clutch lever, it remains idling without engaging with any other gear.
C1 (Planet gear 20B)
Section Y of clutch lever
(Front)
C2 (Planet gear 20A)
III – 9
2.4.3 Power transmission route
Rotation of the motor gear is transmitted as shown below.
E
D
B
Q
A
C2
A: Motor gear B: Sun gear 18/73 C1: Planet gear 20B C2: Planet gear 20A D: Gear 18/26 E: Platen gear F: Gear 16A G: Gear 16B H: Gear 24
C1
H
G
F
P
I
J
K
L
O
M
N
I: Gear 44A J: Gear 21/50 K: Gear 44B L: Separation roller gear M: Idle gear 24A N: Idle gear 24B O: LF roller gear P: Gear 16C Q: Cutter gear
[ 1 ] Recording Mode (Solenoid: OFF, Motor rotation: forward)
C1 D E
A B
C2 (idling)
[ 2 ] Scanning Mode (Solenoid: OFF, Motor rotation: reverse)
C1 (idling)
A B
C2 F G H I J K L M N O
[ 3 ] Copying Mode (Solenoid: ON OFF, Motor rotation: forward)
C1 D E
A B
C2 P F G H I J K L M N O
[ 4 ] Cutter Driving Mode (Solenoid: ON, Motor rotation: reverse)
C1 (idling)
A B
C2 Q
III – 10
3. CONTROL ELECTRONICS
3.1 Configuration
The hardware configuration of the facsimile equipment is shown below.
Speaker
Motor
Handset
Solenoid
Line
2-pin 8-pin
2-pin
4-pin
NCU PCB
(See NOTE below.)
Main PCB
2-pin 6-pin
2-pin 12-pin
2-pin
26-pin
FAX engine
LED array
Thermal recording head
NOTE: The FAX engine includes a CPU and gate array. In the FAX100/570/
615/625/635/675/575M/715M, it also includes a MODEM.
*1 On the NCU PCB are the
following switches:
PC
• PE sensor (SW1)
• Cover sensor (SW2)
• Cutter sensor (SW3)
• Hook switch sensor (SW4)
*
Power
8-pin
supply PCB
*1
2 On the main PCB are the
following photosensors:
• Document front sensor (PH1)
• Document rear sensor (PH2)
14-pin
5-pin
LCD
LEDs
*2
10-pin
CCD PCB
13-pin
FPC key
3.2 Main PCB
The main PCB, which is the nucleus controlling the entire operation of the equipment, con­sists of a FAX engine (ASIC), memories, MODEM (except for FAX100/570/615/625/635/675/
575M/715M)
recording, and power transmission switching.
NCU and Power supply
Speaker
LED array and CCD PCB
Configuration of Facsimile Equipment
, motor drive circuitry, sensor detection circuitry, and analog circuits for scanning,
ROM
E2PROM
DRAM
Image
processor
FAX engine (ASIC)
Motor driver
Sensors
Control panel
Recording head
Motor
PCI
E2PROM: Electrically Erasable Programmable Read-only Memory DRAM: Dynamic Random Access Memory
Block Diagram of Main PCB
III – 11
3.2.1 FAX100/570/615/625/635/675/575M/715M [ 1 ] Primary function group
Main PCB Circuit Diagram 1/4
1 FAX engine (ASIC) which integrates a CPU, MODEM and gate array 2 Clock for MODEM 3 Clock for CPU 4 Clock for calendar clock 5 Reset IC 6 LED array light intensity control circuit and connector 7 Recording head drive voltage detector 8 Control panel connector
III – 12
[ 2 ] ROM and DRAM group
Main PCB Circuit Diagram 2/4
1 ROM (2-megabit. Note that the sample machines for demonstration have a 4-
megabit ROM.)
2 E2PROM (16-kilobit) 3 DRAM (256-kilobit) for the FAX100/570/615/625/635/675 4 DRAMs (256-kilobit) for the FAX575M/715M
III – 13
[ 3 ] Image processing group
Main PCB Circuit Diagram 3/4
1 Image processor (Image processing IC) 2 Connector for the CCD PCB 3 Recording head temperature detector and head connector 4 Motor driver and connector 5 Clutch solenoid connector 6 Document front sensor (photosensor) 7 Document rear sensor (photosensor)
III – 14
[ 4 ] Analog signal processing group
Main PCB Circuit Diagram 4/4
1 Analog front end IC
Processes the analog I/O signals from/to the MODEM.
2 Main-NCU connector 3 Analog signal selectors
3-1: Selects either RL1 or RL2 signals inputted from the communications net-
work.
3-2: Selects either input signals from the handset or those from the MODEM. 3-3: Selects either sound signals (e.g. alarm beeps, key clicks and ringer sounds)
generated by the FAX engine or signals selected by 3-1. 4 Amplifier circuit for signals outputted from the MODEM 5 Amplifier & shaper circuit for signals inputted from the communications network 6 Speaker amplifier circuit
Amplifies sounds issued from the above analog signal selector (3) and feeds them to the speaker.
7 Speaker connector
III – 15
3.2.2 FAX725M/590DT/590MC/825MC/875MC [ 1 ] Primary function group
Main PCB Circuit Diagram 1/5
1 FAX engine (ASIC) which integrates a CPU and gate array. 2 Clock for CPU 3 Clock for calendar clock 4 ROM (2-megabit. Note that the sample machines for demonstration have a 4-
megabit ROM.)
5 E2PROM (16-kilobit in the FAX725M/590DT/590MC/825MC, 32-kilobit in the
FAX875MC)
6 Control panel connector 7 LED array light intensity control circuit and connector 8 Recording head drive voltage detector
III – 16
[ 2 ] DRAM group
Main PCB Circuit Diagram 2/5
1 DRAMs
FAX725M: Two 256-kilobyte DRAMs FAX590DT/590MC/825MC/875MC: Two 512-kilobyte DRAMs
2 Calendar clock backup circuit (for the FAX725M) 3 DRAM backup circuit and nickel-hydrogen battery connector (for the FAX590DT/
590MC/825MC/875MC)
4 DRAM refresh circuit (for the FAX590DT/590MC/825MC/875MC) 5 Reset IC
III – 17
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