Panasonic KX-FT937LA-B Service Manual

© 2006 Panasonic Communications Co., Ltd. All
rights reserved. Unauthorized copying and distribu­tion is a violation of law.

ORDER NO. KMF0606979CE

Facsimile with Digital Answering System

KX-FT937LA-B

B: Black Version
(for Latin America)

2

KX-FT937LA-B

TABLE OF CONTENTS

PAGE PAGE

1 Safety Precautions -----------------------------------------------3

1.1. For Service Technicians ---------------------------------- 3

1.2. AC Caution --------------------------------------------------4

1.3. Personal Safety Precautions ---------------------------- 5

1.4. Service Precautions ---------------------------------------6

2 Warning --------------------------------------------------------------7

2.1. About Lead Free Solder (PbF: Pb free) --------------7

2.2. Insulation Resistance Test -------------------------------7

2.3. Battery Caution ---------------------------------------------7

3 Specifications ------------------------------------------------------8
4 General/Introduction --------------------------------------------- 9

4.1. Optional Accessories--------------------------------------9

4.2. Translation Lists -------------------------------------------- 9

5 Features ------------------------------------------------------------ 10
6 Technical Descriptions---------------------------------------- 11

6.1. Connection Diagram ------------------------------------ 11

6.2. General Block Diagram--------------------------------- 12

6.3. Control Section ------------------------------------------- 14

6.4. Facsimile Section ---------------------------------------- 20

6.5. Sensors and Switches ---------------------------------- 26

6.6. Modem Section ------------------------------------------- 30

6.7. NCU Section ---------------------------------------------- 37

6.8. ITS (Integrated Telephone System) AND
MONITOR SECTION ----------------------------------- 41

6.9. ATAS (Automatic Telephone Answering
System) SECTION--------------------------------------- 41

6.10. Operation Board Section ------------------------------- 43

6.11. LCD Section----------------------------------------------- 44

6.12. Power Supply Board Section ------------------------- 45

7 Location of Controls and Components------------------ 48

7.1. Overview --------------------------------------------------- 48

7.2. Control Panel---------------------------------------------- 49

8 Installation Instructions -------------------------------------- 50

8.1. Installation Space ---------------------------------------- 50

8.2. Connections ----------------------------------------------- 50

8.3. Installing the Recording Paper------------------------ 51

9 Operation Instructions ---------------------------------------- 52

9.1. Setting Your Logo---------------------------------------- 52

10 Test Mode---------------------------------------------------------- 54

10.1. DTMF Single Tone Transmit Selection ------------- 55

10.2. Button Code Table--------------------------------------- 55

10.3. Print Test Pattern----------------------------------------- 55

11 Service Mode----------------------------------------------------- 56

11.1. Programming and Lists--------------------------------- 56

11.2. The Example of the Printed List---------------------- 60

12 Troubleshooting Guide --------------------------------------- 64

12.1. Troubleshooting summary ----------------------------- 64

12.2. Error Messages-Display-------------------------------- 65

12.3. Error Messages Report--------------------------------- 67

12.4. Remote Programming ---------------------------------- 88

12.5. Troubleshooting Details -------------------------------- 91

13 Service Fixture & Tools --------------------------------------117
14 Disassembly and Assembly Instructions --------------11 8

14.1. Disassembly Flowchart --------------------------------118

14.2. Disassembly Procedure ------------------------------ 120

15 Maintenance ---------------------------------------------------- 131

15.1. Maintenance Items and Componet Locations -- 131

15.2. Gear Section -------------------------------------------- 133

15.3. Jams ------------------------------------------------------- 139

15.4. Cleaning -------------------------------------------------- 140

16 Miscellaneous -------------------------------------------------- 141

16.1. Terninal Guide of the ICs, Transistors and
Diodes ----------------------------------------------------- 141

16.2. HOW TO REPLACE THE FLAT PACKAGE IC - 143

16.3. Test Chart------------------------------------------------- 147

17 Schematic Diagram ------------------------------------------- 149

17.1. Digital Board --------------------------------------------- 149

17.2. Analog Board -------------------------------------------- 151

17.3. Operation Board ----------------------------------------153

17.4. Power Supply Board ----------------------------------- 154

18 Printed Circuit Board----------------------------------------- 156

18.1. Digital Board --------------------------------------------- 156

18.2. Analogue Board ---------------------------------------- 158

18.3. Operation Board ----------------------------------------160

18.4. Power Supply Board ----------------------------------- 162

19 Appendix Information of Schematic Diagram ------- 163
20 Exploded View and Replacement Parts List ---------164

20.1. Cabinet, Mechanical and Electrical Parts
Location--------------------------------------------------- 164

20.2. Replacement Parts List -------------------------------170

20.3. Cabinet and Mechanical Parts ---------------------- 170

20.4. Digital Board Parts -------------------------------------171

20.5. Analog Board Parts ------------------------------------ 173

20.6. Operation Board Parts -------------------------------- 174

20.7. Power Supply Board Parts --------------------------- 175

20.8. Fixtures and Tools-------------------------------------- 176

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KX-FT937LA-B

1 Safety Precautions

1. Before servicing, unplug the AC power cord to prevent an electric shock.

2. When replacing parts, use only the manufacturer's recommended components.

3. Check the condition of the power cord. Replace if wear or damage is evident.

4. After servicing, be sure to restore the lead dress, insulation barriers, insulation papers, shields, etc.

5. Before returning the serviced equipment to the customer, be sure to perform the following insulation resistance test to prevent
the customer from being exposed to shock hazards.

1.1. For Service Technicians

ICs and LSIs are vulnerable to static electricity.
When repairing, the following precautions will help prevent recurring malfunctions.

1. Cover the plastic part’s boxes with aluminum foil.

2. Ground the soldering irons.

3. Use a conductive mat on the worktable.

4. Do not touch the IC or LSI pins with bare fingers.

1.1.1. Suggested PBF Solder

There are several types of PbF solder available commercially. While this product is manufactured using Tin, Silver, and Copper,
(Sn+Ag+Cu), you can also use Tin and Copper, (Sn+Cu), or Tin, Zinc, and Bismuth, (Sn+Zn+Bi). Please check the manufac­turer’s specific instructions for the melting points of their products and any precautions for using their product with other materi­als.
The following lead free (PbF) solder wire sizes are recommended for service of this product: 0.3mm, 0.6mm and 1.0mm.

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KX-FT937LA-B

1.1.2. How to recognize that Pb Free Solder is Used

P.C.Boards marked as “PbF” use Pb Free solder. (See the figure below.)

(Example: Digital board)

Note: The “PbF” marked may be found on different areas of the same P.C.Board,depending on manufacture date.

1.2. AC Caution

For safety, before closing the lower cabinet, please make sure of the following precautions.

1. The earth lead is fixed with the screw.

2. The AC lead is connected properly to power supply unit.

3. Wrap the earth lead around the core 5 times.

4. Wrap the AC lead around the core 5 times.

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KX-FT937LA-B

1.3. Personal Safety Precautions

1.3.1. Moving Sections of the Unit

Be careful not to let your hair, clothes, fingers, accessories, etc., become caught in any moving sections of the unit.
The moving sections of the unit are the rollers and a gear. There is a separation roller and a document feed roller which are
rotated by the document feed motor. A gear rotates the two rollers. Be careful not to touch them with your hands, especially
when the unit is operating.

1.3.2. Live Electrical Sections

All the electrical sections of the unit supplied with AC power by the AC power cord are live.
Never disassemble the unit for service with the AC power supply plugged in.

CAUTION:

AC voltage is supplied to the primary side of the power supply unit. Therefore, always unplug the AC power cord before disas­sembling for service.

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KX-FT937LA-B

1.4. Service Precautions

1.4.1. Precautions to Prevent Damage from Static Electricity

Electrical charges accumulate on a person. For instance, clothes rubbing together can damage electric elements or change
their electrical characteristics. In order to prevent static electricity, touch a metallic part that is grounded to release the static
electricity. Never touch the electrical sections such as the power supply unit, etc.

7

KX-FT937LA-B

2Warning

2.1. About Lead Free Solder (PbF: Pb free)

Note:

In the information below, Pb, the symbol for lead in the periodic table of elements, will refer to standard solder or solder that con­tains lead.

We will use PbF solder when discussing the lead free solder used in our manufacturing process which is made from Tin, (Sn),
Silver, (Ag), and Copper, (Cu).

This model, and others like it, manufactured using lead free solder will have PbF stamped on the PCB. For service and repair
work we suggest using the same type of solder.

Caution

• PbF solder has a melting point that is 50° ~ 70° F, ( 30 ° ~ 40°C) higher than Pb solder. Please use a soldering iron with tempera­ture control and adjust it to 700° ± 20° F, ( 3 7 0° ± 10°C).

• Exercise care while using higher temperature soldering irons.: Do not heat the PCB for too long time in order to prevent solder
splash or damage to the PCB.

• PbF solder will tend to splash if it is heated much higher than its melting point, approximately 1100°F, ( 6 0 0 °C).

• When applying PbF solder to double layered boards, please check the component side for excess which may flow onto the
opposite side (See figure, below).

2.2. Insulation Resistance Test

1. Unplug the power cord and short the two prongs of the plug with a jumper wire.

2. Turn on the power switch.

3. Measure the resistance value with an ohmmeter between the jumpered AC plug and each exposed metal cabinet part
(screw heads, control shafts, bottom frame, etc.).
Note: Some exposed parts may be isolated from the chassis by design. These will read infinity.

4. If the measurement is outside the specified limits, there is a possibility of a shock hazard.

2.3. Battery Caution

CAUTION

Danger of explosion if the battery is incorrectly replaced. Replace only with the same or equivalent type recommended by the
manufacturer. Dispose of used batteries according to the manufacturer’s Instructions.

The lithium battery is a critical component (type No. CR2032). Please observe for the proper polarity and the exact location
when replacing it and soldering the replacement lithium battery in.

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KX-FT937LA-B

3Specifications

* 1 Transmission speed depends upon the contents of the pages, resolution, telephone line conditions and capability of the other
party’s machine.

*

2

Transmission speed is based upon the ITU-T No. 1 Test Chart with original mode. If the capability of the other party’s machine is

inferior to your unit, the transmission time may be longer.

*

3

If an error occurs during fax reception, such as a paper jam or if the recording paper runs out, the fax and subsequent faxes will

be retained in memory.

*

4

Recording time may be reduced by the calling party’s background noise.

Note:

Design and specifications are subject to change without notice.

Applicable Lines: Public Switched Telephone Network
Document Size: Max. 216 mm in width

Max. 600 mm in length

Effective Scanning Width: 208 mm
Recording Paper Size: 216 × max. 30 m roll
Effective Printing Width: 208 mm

Transmission Time*

1

: Approx. 15 s/page (Original mode)*

2

Scanning Density: Horizontal: 8 pels/mm

Verti cal:

3.85 lines/mm - in standard resolution,

7.7 lines/mm - in fine/photo resolution,

15.4 lines/mm - in super fine resolution

Photo resolution: 64-level
Scanner Type: Contact Image Sensor
Printer Type: Thermal printing
Data Compression System: Modified Huffman (MH), Modified READ (MR)
Modem Speed: 9,600 / 7,200 / 4,800 / 2,400 bps; Automatic Fallback
Operating Environment: 5 - 35°C, 20 - 80% RH (Relative Humidity)
Dimensions (H×W×D): Approx. height 121 mm × width 352 mm × depth 224 mm
Mass (Weight): Approx. 2.8 kg
Power Consumption: Standby: Approx. 1.4 W

Transmission: Approx. 13 W
Reception: Approx. 30 W (When receiving a 20% black document)
Copy: Approx. 35 W (When copying a 20% black document)
Maximum: Approx. 120 W (When copying a 100% black document)

Power Supply: 120 V AC, 60 Hz
Fax Memory Capacity*

3

:

Approx. 28 pages of memory reception
(Based on the ITU-T No. 1 Test Chart in standard resolution, with original mode.)

Voice Memory Capacity*

4

:

Approx. 18 minutes of recording time including greeting messages

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KX-FT937LA-B

4 General/Introduction

4.1. Optional Accessories

*1 Use only the included or specified recording paper. Using other recording paper may affect print quality and/or cause exces­sive wear to the thermal head.

4.2. Translation Lists

4.2.1. Other

4.2.2. Error Message (Report)

Model No. Item Specifications/Usage

KX-A106

Standard thermal recording paper*

1

216 mm × 30 m roll, with 25 mm core

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KX-FT937LA-B

4.2.3. Error Message (Display)

5Features

General

• LCD (Liquid Crystal Display) readout

Facsimile

• Automatic document feeder (10 sheets)

• Resolution: Standard/Fine/Photo/Super Fine (64 level)

• Broad cast

Integrated Telephone System

• Redialing function

• Phonebook function (100 names)

• Caller ID compatible**
**Feature requires a subscription to caller identification ser­vices offered by certain local telephone companies for a tee.
You and your caller(s) must be in areas that provide caller
identification services, and compatible equipment must be
used by both telephone companies. Feature not available
when the unit is connected to a PBX system.

Enhanced Copier Function

• 64-Level halftone

Digital Answering System

• Voice Time/Day Stamp

• Quick & Slow Playback Speeds

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KX-FT937LA-B

6 Technical Descriptions

6.1. Connection Diagram

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KX-FT937LA-B

6.2. General Block Diagram

The following is an outline of each device IC on the digital board. (Refer to General Block Diagram (P.13).).

1. ASIC (IC1)
Composed mainly of an address decoder and a modem control.
Controls the general FAX operations.
Controls the operation panel I/F.
Controls the thermal head I/F and CIS I/F.
Performs the image processing.
CPU and Real time clock
Provides the reset pulse for each of the major ICs.

2. Flash ROM (IC2)
Contains all of the program instructions on the unit operations.
This memory is used mainly for the parameter working in the storage area.

3. Dynamic RAM (IC4)
This memory is used mainly for the parameter working in the storage area.

4. MODEM (IC5)
Performs the modulation and the demodulation for FAX communication.

5. FLASH MEMORY (IC6)
Voice Prompt (TAM) D/L (DownLoad) area.

6. Read Section
CIS image sensor to read transmitted documents.

7. Motor Driver (IC7)
Drives the transmission motor and the reception motor.

8. Thermal Head
Contains heat-emitting elements for dot matrix image printing.

9. Sensor Section
Composed of a cover open and film end switch, a document set switch, a document top switch, a paper top sensor and a
motor position switch.

10. Power Supply Board Switching Section
Supplies +6V and +24V to the unit.

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KX-FT937LA-B

6.2.1. General Block Diagram

POWER SUPPLY BOARD OPERATION PANEL

DIGITAL BOARD ANALOG BOARD

DRAM

4Mbit

3.3V

IC4

FLASH

4Mbit

PROGRAM

3.3V

IC2

FET

ANALOG

SW

IC10

32.256MHz

IC5

MODEM

BOA

R

x

T

x

THERMAL

HEAD

BUFFER

+24V

THON

STB1,2

THLAT,THCLK,

THDAT

2 strobe

Tr

CIS

+5V

3.3V chip

LED ON

CLK, SIG

IC7

MOTOR DRIVER

CPU

OP-PANEL

I/F

256kbit

ROM

64Kbit

SRAM

A/D

IMAGE

PROCESSING

RTC

SERIAL

I/F

MOTOR

I/F

PRINTER

CONTROL

VOL

TONE

32.768KHz

OSC

24MHz

MOTOR

SPEAKER HANDSET

To FLASH

PROGRAMMER

+24

+6V

REG

REG

+5V

+6V

+24V+6V

GATE

ARRAY

LCD PANEL

English 2 lines

Tact SW

KEY MATRIX

SENSOR x2

(Doc sensor,

Read position sensor)

MESSAGE

MIC

FLASH

4Mbit

(TAM Model)

3.3V

IC6

LINERX

CPC

MONRX

LINE

Relay

Transformer

LINETX

JAM

HOOK

PAPER

(Not Used)

(Not Used)

(Not Used)

BELL

PCONT

ASIC

IC1

TONE1

ACK_EN

H/SRX

H/STX_MUTE

+24V

RLY

+3.3

RESET

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KX-FT937LA-B

6.3. Control Section

6.3.1. ASIC (IC1)

This custom IC is used for the general FAX operations.

1. CPU:
This model uses a Z80 equivalent to the CPU operating
at 12 MHz. Most of the peripheral functions are performed
by custom-designed LSIs. Therefore, the CPU only works
for processing the results.

2. RTC:
Real Time Clock

3. DECODER:
Decodes the address.

4. ROM/RAM I/F:
Controls the SELECT signal of ROM or RAM and the
bank switching.

5. CIS I/F:
Controls the document reading.

6. IMAGE DATA RAM:
This memory is programmed into the ASIC and uses 8
KB for the image processing.

7. THERMAL HEAD I/F:
Transmits the recorded data to the thermal head.

8. MOTOR I/F:
Controls the transmission motor which feeds the docu­ment.
Controls the receiving motor which feeds the recording
paper.

9. OPERATION PANEL I/F:
Serial interface with Operation Panel.

10. I/O PORT:
I/O Port Interface.

11. ANALOGUE UNIT:
Electronic volume for the monitor.
Sends beep tones, etc.

Note*:

This memory is incorporated into the ASIC (IC1) and used for the image processing.

Descriptions of Pin Distribution (IC1)

NO. SIGNAL I/O POWER SUPPLIED

VOLTAGE

DESCRIPTION

1 VSSA GND POWER SOURCE (ANALOG GND)
2 VDDA 3.3 3.3V POWER SOURCE (ANALOG +3.3V)
3 AIN1 A 3.3V CIS IMAGE SIGNAL INPUT (ATN1)
4 AIN2 A 3.3V THERMISTOR TEMPERATURE WATCH INPUT
5 AIN3 A 3.3V LINE VOLTAGE DETECTION SIGNAL INPUT (DCIN)
6 AMON A 3.3V ANALOG SIGNAL MONITOR TERMINAL
7 VSS GND POWER SOURCE (GND)
8 X32OUT O 3.3V/BATT RTC (32.768KHz) CONNECTION

9 X32IN I 3.3V/BATT RTC (32.768KHz) CONNECTION
10 VDD (3.3V / B) ----- POWER SOURCE (+3.3V/LITHIUM BATTERY)
11 XBACEN I 3.3V/BATT BACKUP ENABLE
12 XRAMCS O 3.3V/BATT XRAMCS
13 VDD (3.3V / B) ----- POWER SOURCE(+3.3V / LITHIUM BATTERY)
14 VDD (2.5V/B) ----- POWER SOURCE (+2.5V / LITHIUM BATTERY)
15 FTG O 3.3V SH SIGNAL OUTPUT FOR CIS (FTG)
16 F1 O 3.3V 01 SIGNAL OUTPUT FOR CIS (F1)
17 F2/OP O 3.3V OUTPUT PORT (HEADON)
18 FR/OP O 3.3V OUTPUT PORT (MDMRST)
19 CPC I 3.3V INPUT PORT (CPC)
20 RVN I 3.3V INPUT PORT (PAPER)
21 IRDATXD/IOP I 3.3V INPUT PORT (JAM)
22 IRDARXD/IOP80 O 3.3V OUTPUT PORT (HSTX MUTE)
23 TXD/IOP I 3.3V INPUT PORT (BELL)
24 RXD/IOP I/O 3.3V PORT (TELRXEN)
25 XRTS/IOP I 3.3V INPUT PORT (PSHORT)
26 XCTS/IOP I/O 3.3V PORT (MDMTXEN)
27 VDD (2.5V) ----- POWER SOURCE (+2.5V)
28 TONE1 A 3.3V TONE OUTPUT
29 TONE2 A 3.3V TONE OUTPUT
30 VOLUREF A 3.3V ANALOG REF VOLTAGE
31 VOLUOUT A 3.3V VOLUME OUTPUT
32 VOLUIN A 3.3V VOLUME INPUT
33 XNMI I 3.3V HIGH FIXED
34 FMEMDO/IOP O 3.3V OUTPUT PORT (LED ON)
35 VDD (3.3V) ----- POWER SOURCE (+3.3V)
36 VSS GND POWER SOURCE (GND)
37 VSS GND POWER SOURCE (GND)

15

KX-FT937LA-B

38 VDD (3.3V) ----- POWER SOURCE (+3.3V)
39 MIDAT/IOP I/O 3.3V PORT (TONE1EN)
40 MICLK/IOP O 3.3V OUTPUT PORT (TONE2EN)
41 MILAT/IOP I/O 3.3V PORT (HSRXEN)
42 20KOSC/IOP O 3.3V OUTPUT PORT (PWRCNT)
43 XWAIT I 3.3V INPUT PORT (HOOK)
44 HSTRD/IOP I 3.3V INPUT PORT (TEST)
45 HSTWR/IOP O 3.3V OUTPUT PORT (BLEEDER_ON)
46 XOPRBE O 3.3V OUTPUT PORT (MFCS)
47 ADR15 O 3.3V CPU ADDRESS BUS 15 (NOT USED)
48 ADR14 O 3.3V CPU ADDRESS BUS 14 (NOT USED)
49 ADR13 O 3.3V CPU ADDRESS BUS 13 (NOT USED)
50 VDD (2.5V) ----- POWER SOURCE (+2.5V)
51 XOUT O 3.3V SYSTEM CLOCK (24MHz)
52 XIN I 3.3V SYSTEM CLOCK (24MHz)
53 VSS GND POWER SOURCE (GND)
54 VDD (3.3V) ----- POWER SOURCE (+3.3V)
55 XTEST O 3.3V 24MHz CLOCK
56 TEST1 I 3.3V HIGH FIXED
57 TEST2 I 3.3V HIGH FIXED
58 TEST3 I 3.3V HIGH FIXED
59 TEST4 I 3.3V HIGH FIXED
60 XMDMINT I 3.3V MODEM INTERRUPT
61 XMDMCS O 3.3V MODEM CHIP SELECT
62 XRAS/IOP O 3.3V DRAM ROW ADDRESS STROBE (RAS)
63 XCAS1/IOP O 3.3V DRAM COLUMN ADDRESS STROBE (CAS)
64 XCAS2/IOP I 3.3V PORT (SPMUTE)
65 XRESCS2 O 3.3V FLASH CHIP SELECT (XRESCS2)
66 DB3 I/O 3.3V CPU DATA BUS 3
67 DB2 I/O 3.3V CPU DATA BUS 2
68 DB4 I/O 3.3V CPU DATA BUS 4
69 DB1 I/O 3.3V CPU DATA BUS 1
70 DB5 I/O 3.3V CPU DATA BUS 5
71 VDD (3.3V) ----- POWER SOURCE (+3.3V)
72 VSS GND POWER SOURCE (GND)
73 VSS GND POWER SOURCE (GND)
74 VDD (3.3V) ----- POWER SOURCE (+3.3V)
75 DB0 I/O 3.3V CPU DATA BUS 0
76 DB6 I/O 3.3V CPU DATA BUS 6
77 DB7 I/O 3.3V CPU DATA BUS 7
78 XROMCS O 3.3V FLASH (IC2) CHIP SELECT
79 RD O 3.3V CPU RD
80 WR O 3.3V CPU WR
81 ADR0 O 3.3V CPU ADDRESS BUS 0
82 ADR1 O 3.3V CPU ADDRESS BUS 1
83 ADR2 O 3.3V CPU ADDRESS BUS 2
84 ADR3 O 3.3V CPU ADDRESS BUS 3
85 ADR4 O 3.3V CPU ADDRESS BUS 4
86 ADR5 O 3.3V CPU ADDRESS BUS 5
87 VSS GND POWER SOURCE (GND)
88 VDD (2.5V) ----- POWER SOURCE (+2.5V)
89 ADR6 O 3.3V CPU ADDRESS BUS 6
90 ADR7 O 3.3V CPU ADDRESS BUS 7
91 ADR8 O 3.3V CPU ADDRESS BUS 8
92 ADR9 O 3.3V CPU ADDRESS 9
93 ADR10 O 3.3V CPU ADDRESS 10
94 ADR11 O 3.3V CPU ADDRESS 11
95 ADR12 O 3.3V CPU ADDRESS 12
96 RBA0 O 3.3V ROM/RAM BANK ADDRESS 0
97 RBA1 O 3.3V ROM/RAM BANK ADDRESS 1
98 RBA2 O 3.3V ROM/RAM BANK ADDRESS 2

99 RBA3 O 3.3V ROM/RAM BANK ADDRESS 3
100 RBA4 O 3.3V ROM/RAM BANK ADDRESS 4
101 RBA5 O 3.3V ROM/RAM BANK ADDRESS 5
102 RBA6/IOP96 O 3.3V OUTPUT PORT (NC)
103 STB1 O 3.3V STROBE SIGNAL OUTPUT TO THERMAL HEAD

NO. SIGNAL I/O POWER SUPPLIED

VOLTAGE

DESCRIPTION

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KX-FT937LA-B

Connection to operation reset circuit

104 STB2 O 3.3V STROBE SIGNAL OUTPUT TO THERMAL HEAD
105 STB3 O 3.3V OUTPUT PORT (NC)
106 XRESET I 3.3V RESET INPUT
107 VDD (3.3V) ----- POWER SOURCE (+3.3V)
108 VSS GND POWER SOURCE (GND)
109 VSS GND POWER SOURCE (GND)

110 VDD (3.3V) ----- POWER SOURCE (+3.3V)
111 XORESET O 3.3V NOT USED
112 VDD(5V) ----- POWER SOURCE (+5V)
113 VSS GND POWER SOURCE (GND)
114 XRESETI I 3.3V RESET INPUT
115 WDERR O 3.3V WATCHED ERROR OUTPUT SIGNAL
116 THDAT O 3.3V RECORDED IMAGE OUTPUT (THDAT)
117 THCLK O 3.3V CLOCK OUTPUT FOR DATA TRANSFER (THCLK)
118 THLAT O 3.3V PULSE OUTPUT FOR DATA LATCH (THLAT)

119 STBNP I 3.3V INPUT PORT (MOT-POS)
120 RM0/IOP O 3.3V MOTOR A PHASE
121 RM1/IOP O 3.3V MOTOR B PHASE
122 RM2/IOP O 3.3V MOTOR /A PHASE
123 RM3/IOP O 3.3V MOTOR /B PHASE
124 RXE/IOP O 3.3V MOTOR ENABLE
125 TMO O 3.3V OUTPUT PORT (NC)
126 VDD (2.5V) ----- POWER SOURCE (+2.5V)
127 VSS GND POWER SOURCE (GND)
128 TM1/IOP O 3.3V OUTPUT PORT (ACK_EN)
129 TM2/IOP O 3.3V OUTPUT PORT (CISON)
130 TM3/IOP O 3.3V OUTPUT PORT (RLY)
131 TXE/IOP I 3.3V INPUT PORT (CUT_POS)
132 KSTART O 3.3V OPERATION PANEL CONTROL
133 KLATCH O 3.3V OPERATION PANEL CONTROL
134 KSCLK O 3.3V OPERATION PANEL CONTROL
135 KTXD O 3.3V OPERATION PANEL CONTROL
136 KRXD I 3.3V OPERATION PANEL CONTROL
137 FMEMCLK/IOP O 3.3V OUTPUT PORT (OPRESET)
138 FMEMDI/IOP O 3.3V OUTPUT PORT (NC)
139 ADSEL1 O 3.3V CHANNEL SELECT SIGNAL FOR AIN2
140 VDDA (2.5V) 2.5V POWER SOURCE (ANALOG +2.5V)
141 VREFB A 3.3V A/D CONVERTER'S ZERO STANDARD VOLTAGE

OUTPUT
142 VCL A 3.3V ANALOG PART STANDARD VOLTAGE SIGNAL
143 VREFT A 3.3V A/D CONVERTER'S FULL SCALE VOLTAGE OUTPUT
144 VSSA GND POWER SOURCE (ANALOG GND)

NO. SIGNAL I/O POWER SUPPLIED

VOLTAGE

DESCRIPTION

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KX-FT937LA-B

6.3.2. Flash Memory (IC2)

This 512KB ROM (FLASH MEMORY) carries a common area of 32KB and bank areas which each have 8KB (BK4~BK63). The
addresses from 0000H to 7FFFH are for the common area and from 8000H to 9FFFH are for the bank areas.

6.3.3. Dynamic RAM (IC4)

The DRAM serves as CPU and receives memory.
The address is F200H~F3FFH (DRAM access window 1) and F600H~F7FFH (DRAM access window 2).

6.3.4. Reset Circuit (Watch dog timer)

The output signal (reset) from pin 4 of the voltage detect IC (IC3) is input to the ASIC (IC1) 114 pin.

1. During a momentary power interruption, a positive reset pulse of 50~70 msec is generated and the system is reset com­pletely.

2. The watch dog timer, built-in the ASIC (IC1), is initialized by the CPU about every 1.5 ms.
When a watch dog error occurs, pin 115 of the ASIC (IC1) becomes low level.
The terminal of the 'WDERR' signal is connected to the reset line, so the 'WDERR' signal works as the reset signal.

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KX-FT937LA-B

6.3.5. RTC Back up Circuit

1. Function
This unit has a lithium battery (BAT1) which works for the Real Time Clock (RTC, Integrated into ASIC:IC1).
The RTC continues functioning, even when the power switch is OFF, backed up by a lithium battery.

2. Circuit Operation
When the power is turned ON, power is supplied to RTC (IC1).
At this time, the voltage at pin 14 of RTC (IC1) is +3.3V. When the power is turned OFF, the battery supplies the power to RTC
through J1, R80, D503. At that time, the voltage at pin 14 of IC1 are about +2.5V. When the power is OFF and the +5V and
+3.3V voltages decrease, the LOW is input to pin 114 of IC1. Pin 111 of IC1 outputs the reset signals. Pin 11 of IC1 become
low, then RTC (IC1) go into the back up mode, when the power consumption is lower.

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6.3.6. Supervision Circuit for the Thermal Head Temperature

1. Function
The thermistor changes the resistor according to the temperature and uses the thermistor's characteristics. The output of pin
139 of IC1 becomes a low level. Then when it becomes a high level, it triggers point A. In point C, according to the voltage
output time, the thermal head's temperature is detected.
After the thermal head temperature is converted to voltage in B, it is then changed to digital data in the A/D converter inside
IC1. The CPU decides the strobe width of the thermal head according to this value. Therefore, this circuit can keep the ther­mal head at an even temperature in order to stabilize the printing density and prevent the head from being overheated.

CROSS REFERENCE:

Thermal Head (P.22)

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6.4. Facsimile Section

6.4.1. Image Data Flow During Facsimile Operation

Copy (Fine, Super-Fine, Photo)

1. Line information is read by CIS (to be used as the reference white level) via route (1), and is input to IC1. Refer to Block Dia­gram (P.21)

2. In IC1, the data is adjusted to a suitable level for A/D conversion in the Analog Signal Processing Section, and via route (2) it
is input to A/D conversion (8 bit). After finishing A/D conversion, the data is input to the Image Processing Section via route
(3). Then via route (4) and route (5), it is stored in RAM as shading data.

3. The draft’s information that is read by CIS is input to IC1 via route (1). After it is adjusted to a suitable level for A/D conversion
via route (2), the draft’s information is converted to A/D (8 bit), and it is input to the Image Processing Section. The other side,
the shading data which flows from RAM via route (6) and route (7), is input to the Image Processing Section. After finishing
the draft’s information image processing, white is regarded as “0” and black is regarded as “1”. Then via routes (4) and (5),
they are stored in RAM.

4. The white/black data stored as above via routes (6) and (8) is input to the P/S converter. The white/black data converted to
serial data in the P/S converter is input to the Thermal Head via route (9) and is printed out on recording paper.

Note:

Fine: Reads 3.85 lines/mm
Super Fine: Reads 7.7 lines/mm
Photo: Reads 15.4 lines/mm

Transmission

1. Same processing as Copy items 1 - 3.

2. The data stored in the RAM of IC1 is output from IC1 via routes (6) and (10), and is stored in the system bus.
Via route (11), it is stored in the communication buffer inside DRAM (IC4).

3. While retrieving data stored in the communication buffer synchronous with the modem, the CPU (inside IC1) inputs the data to
the modem along route (12), where it is converted to serial analogue data and forwarded over the telephone lines via the
NCU Section.

Reception

1. The serial analog image data is received over the telephone lines and input to the modem via the NCU section, where it is
demodulated to parallel digital data. Then the CPU (IC1) stores the data in the communication buffer DRAM (IC4) along route
(11).

2. The data stored in DRAM (IC4) is decoded by the CPU (IC1) via route (12), and is stored in RAM via routes (13) and (5).

3. Same processing as Copy item 4.

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6.4.2. Block Diagram

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6.4.3. Thermal Head

1. Function
This unit utilizes state of the art thermal printer technology.
The recording paper (roll paper) is chemically processed. When the thermal head contacts this paper it emits heat momen­tarily, and black dots (appearing like points) are printed on the paper. If this continues, letters and/or diagrams appear, and the
original document is reproduced.

2. Circuit Operation
There are 27 driver ICs aligned horizontally on the thermal head and each one of these ICs can drive 64 heat emitting regis­ters. This means that one line is at a density of 64×27=1728 dots=(8 dots/mm).
White/Black (white=0, black=1) data in one line increments is synchronized at IC1 pin 117 (THCLK), and sent from IC1 pin 116
(THDAT) to the shift register of the ICs. The shift registers of the 27 ICs are connected in series, and upon the shift of dot
increment 1728, all the shift registers become filled with data, and a latch pulse is emitted to each IC from IC1 pin 118
(THLAT).With this latch pulse, all the contents of the shift registers are latched to the latch registers. Thereafter, through the
addition of strobes from the IC1 pins (103 - 104) only black dot locations (=1) among latched data activates the driver, and the
current passes to heat the emitting body causing heat emission.
Here, the two line strobes, STB1 and STB2, impress at intervals of 9.216 msec, as required for one-line printout.
The sequence is shown on the next page. [Moreover, for the strobe width, the thermistor value inside the thermal head is
detected according to IC1 pin 4. (See Block Diagram (P.21).) Depending on that value, the strobe width is recorded in
FLASH (IC2).
Accordingly, the strobe width is determined.
When the thermal head is not used, the IC1 (17, HEADON) becomes low, Q6 turns OFF, Q7 turns OFF, and the +24 V power
supply for the thermal head driver is not impressed to protect the IC.

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6.4.4. Scanning Block

The scanning block of this device consists of a control circuit and a contact image sensor made up of a celfoc lens array, a light
source, and photoelectric conversion elements.

When an original document is inserted and the start button pressed, pin 129 of IC1 goes to a high level and the transistor Q14 turns
on.This applies voltage to the light source to light it. The contact image sensor is driven by each of the FTG-F1 signals output from
IC1, and the original image illuminated by the light source undergoes photoelectric conversion to output an analogue image signal
(AIN). The analogue image signal is input to the system ASIC on AIN1 (pin 3 of IC1) and converted into 8-bit data by the A/D con­verter inside IC1. Then this signal undergoes digital processing in order to obtain a high-quality image.

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6.4.5. Stepping Motor Drive Circuit

1. Function
One individual stepping motor is used for transmission and reception. It feeds the document or recording paper synchronized
for reading or printing.

2. Circuit Operation
During motor drive, ASIC IC1 pin 124 becomes a high level, and Q2 and Q1 go ON as a result. +24 V is supplied tothe motor
coil.
Stepping pulses are output from gate array IC1, causing driver IC7 to go ON. The motor coil is energized sequentially in 2
phase increments or 1-2 phase increments, which causes a 1-step rotation. A 1-step rotation is 0.13mm of recording paper or
document paper. The timing chart is below.

Stepping Motor Phase Pattern

When the motor is OFF, gate array IC1 pin 124 becomes a low level and Q2 and Q1 also turns OFF. Instead of +24V, +5V is suplied
through D501 so that the motor is held in place.

Function Mode Phase Pattern Speed

Copy Fine/Photo 1-2 432 pps

Super Fine 1-2 216 pps

FAX STD 2 432 pps

Fine/Photo 1-2 432 pps
Super Fine 1-2 216 pps

——— Paper Feed 2 432 pps

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6.5. Sensors and Switches

All of the sensors and switches are shown below.

Sensor Circuit

Location

Sensor Sensor or Switch Name Message Error

DIGITAL CN5 Motor Position Sensor [CALL SERVICE]

CN6 Cutter Position Sensor [PAPER JAMED]

ANALOG SW1 Recording Paper Sensor [CHECK COVER] and [OUT OF PAPER]

SW2 Hook SW ————
SW3 JAM Sensor [PAPER JAMED]

Operation Panel SW39 Document Top Sensor [REMOVE DOCUMENT]

SW38 Document Set Sensor [CHECK DOCUMENT]

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6.5.1. Motor Position Sensor

This sensor is a detection switch for recording the position of the CAM.

Digital Board

6.5.2. Cutter Position Sensor

Digital Board

6.5.3. Recording Paper Sensor (SW1)

When there is no recording paper, the plate is separated from the switch lever and the switch turns off. Pin 20 of IC1 becomes a
high level. When there is recording paper, the plate pushes the switch lever and the switch turns ON. Pin 20 of IC1 becomes a low
level.

Analog Board

Signal (IC1-119 Pin)
Home position Low level
Other High level

Signal (IC1-131 Pin)
Home position Low level
Other High level

Signal (IC1-20 Pin)
Paper Low level
No paper High level

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6.5.4. Hook Switch (SW2)

When the handset is lifted, the switch turns ON, and the signal at pin 43 of IC1 becomes low.
When the handset is returned, the switch turns OFF, and the signal at pin 43 of IC1 becomes high.

Digital Board

6.5.5. Jam Sensor (SW3)

The JAM sensor is a detection switch for determining whether the recording paper edge is in the correct position or not. If the
recording paper cannot be detected correctly at the JAM sensor position even when recording paper is present, then JAM is dis­played. If the recording paper is at the sensor position, then the switch turns on the IC1-21pin switches to a high level.

Analog Board

SW Signal
ON-Hook OFF High level (IC1-43 pin)
OFF-Hook ON Low level

Signal (IC1-21 Pin)
Paper Low level
No paper High level

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6.5.6. Document Top Sensor (SW39)

When a document is brought to the read position, the SW becomes ON, and the input signal of IC1-5 pin (Operation) becomes a
low level. When there is no document at the read position, the SW becomes OFF, and the input signal of IC1-5 pin (Operation)
becomes a high level.

Operation Board

6.5.7. Document Set Sensor (SW38)

When a document is set, the SW becomes ON, and input signal of IC1-6 pin (Operation) becomes a low level.
When there is no document, the SW becomes OFF, and the input signal of IC1-6 pin (Operation) becomes a high level.

Operation Board

Signal (IC1-5 pin)
Out of the Read Position High level
At the Read Position Low level

Signal (IC1-6 pin)
No document High level
Set document Low level

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6.6. Modem Section

6.6.1. Function

The unit uses a 1 chip modem (IC5) that serves as an interface between the control section for FAX transmission and reception
and the telephone line. During a transmitting operation, the digital image signals are modulated and sent to the telephone line.
During a receiving operation, the analogue image signals which are received via the telephone line are demodulated and con­verted into digital image signals. The communication format and procedures for FAX communication are standardized by ITU-T.
This 1 chip modem (IC5) has hardware which sends and detects all of the necessary signals for FAX communication (DTMF).
It can be controlled by writing commands from the CPU (IC1: inside ASIC) to the register in the modem (IC5).
This modem (IC5) also sends DTMF signals, generates a call tone (from the speaker), and detects a busy tone and dial tones.

Overview of Facsimile Communication Procedures (ITU-T Recommendation):

1. ON CCITT (International Telegraph and Telephone Consultative Committee)
The No. XIV Group of CCITT, one of the four permanent organizations of the International Telecommunications Union (ITU),
investigates and make recommendations on international standards for facsimiles.

2. Definition of Each Group

• Group I (G1)
Official A-4 size documents without using formats which reduce the band width of a signal are sent over telephone lines.Deter­mined in 1968.
Transmission for about 6 minutes at a scanning line density of 3.85 lines/mm.

• Group II (G2)
Using reduction technology in the modulation/demodulation format, an A-4 size document is sent at an official scanning line den­sity of 3.85 lines/mm for about 3 minutes.
Methods to suppress redundancy are not used.
Determined in 1976.

• Group III (G3)
Method of suppressing redundancy in the image signal prior to modulation is used. An A-4 size document is sent within about
one minute.
Determined in 1980.

• Group IV (G4)
Transmission is via the data network. A method is provided for suppressing redundancy in signals prior to transmission, and
error-free reception of transmission is possible.
The scope of these facsimile applications is not limited simply to transmission of written statements. Through symbiotic linkages
with other communication methods, it can be expected to expand to include integrated services.