Panasonic KX-FT937 Service Manual

Name: Panasonic KX-FT937
Brand: Panasonic
SKU: 5872885
Rating: 4.5 (2 reviews)

4.5 (2)

ORDER NO. KMF0606979CE

Facsimile with Digital Answering System

KX-FT937LA-B

B: Black Version

(for Latin America)

KX-FT937LA-B

	PAGE		PAGE
1	Safety Precautions -----------------------------------------------	3	15.3. Jams -------------------------------------------------------	139
	1.1. For Service Technicians----------------------------------	3	15.4. Cleaning --------------------------------------------------	140
	1.2. AC Caution --------------------------------------------------	4	16 Miscellaneous --------------------------------------------------	141
	1.3. Personal Safety Precautions----------------------------	5	16.1. Terninal Guide of the ICs, Transistors and
	1.4. Service Precautions ---------------------------------------	6	Diodes -----------------------------------------------------	141
2	Warning --------------------------------------------------------------	7	16.2. HOW TO REPLACE THE FLAT PACKAGE IC - 143
	2.1. About Lead Free Solder (PbF: Pb free) --------------	7	16.3. Test Chart-------------------------------------------------	147
	2.2. Insulation Resistance Test -------------------------------	7	17 Schematic Diagram-------------------------------------------	149
	2.3. Battery Caution ---------------------------------------------	7	17.1. Digital Board ---------------------------------------------	149
3	Specifications ------------------------------------------------------	8	17.2. Analog Board --------------------------------------------	151
4	General/Introduction---------------------------------------------	9	17.3. Operation Board ----------------------------------------	153
	4.1. Optional Accessories--------------------------------------	9	17.4. Power Supply Board-----------------------------------	154
	4.2. Translation Lists --------------------------------------------	9	18 Printed Circuit Board-----------------------------------------	156
5	Features------------------------------------------------------------	10	18.1. Digital Board ---------------------------------------------	156
6	Technical Descriptions----------------------------------------	11	18.2. Analogue Board ----------------------------------------	158
	6.1. Connection Diagram ------------------------------------	11	18.3. Operation Board ----------------------------------------	160
	6.2. General Block Diagram---------------------------------	12	18.4. Power Supply Board-----------------------------------	162
	6.3. Control Section -------------------------------------------	14	19 Appendix Information of Schematic Diagram -------	163
	6.4. Facsimile Section ----------------------------------------	20	20 Exploded View and Replacement Parts List ---------	164
	6.5. Sensors and Switches ----------------------------------	26	20.1. Cabinet, Mechanical and Electrical Parts
	6.6. Modem Section-------------------------------------------	30	Location---------------------------------------------------	164
	6.7. NCU Section ----------------------------------------------	37	20.2. Replacement Parts List -------------------------------	170
	6.8. ITS (Integrated Telephone System) AND		20.3. Cabinet and Mechanical Parts ----------------------	170
	MONITOR SECTION -----------------------------------	41	20.4. Digital Board Parts -------------------------------------	171
	6.9. ATAS (Automatic Telephone Answering		20.5. Analog Board Parts ------------------------------------	173
	System) SECTION---------------------------------------	41	20.6. Operation Board Parts --------------------------------	174
	6.10. Operation Board Section-------------------------------	43	20.7. Power Supply Board Parts ---------------------------	175
	6.11. LCD Section-----------------------------------------------	44	20.8. Fixtures and Tools--------------------------------------	176
	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--------------	118
	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

KX-FT937LA-B

1Safety 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.

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.

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.

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.

KX-FT937LA-B

2 Warning

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, (370° ± 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, (600°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.

KX-FT937LA-B

3 Specifications

Applicable Lines:	Public Switched Telephone Network
Document Size:	Max. 216 mm in width
Effective Scanning 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
	Vertical:
	3.85 lines/mm - in standard resolution,
	7.7 lines/mm - in fine/photo resolution,
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)
Power Supply:	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

* 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.

KX-FT937LA-B

4 General/Introduction

4.1.Optional Accessories

Model No.	Item	Specifications/Usage
KX-A106	Standard thermal recording paper*1	216 mm × 30 m roll, with 25 mm core

*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)

KX-FT937LA-B

4.2.3.Error Message (Display)

5 Features

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

KX-FT937LA-B

6 Technical Descriptions

6.1.Connection Diagram

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.

POWER SUPPLY BOARD

OPERATION PANEL

.1.2.6

+24

Tact SW

LCD PANEL

General

English 2 lines

MESSAGE

+6V

GATE

SENSOR x2

Block

ARRAY

(Doc sensor,

Read position sensor)

KEY MATRIX

MIC

(Not Used)

Diagram

PCONT

+6V

+24V

DIGITAL BOARD

ANALOG BOARD

+6V

DRAM

FLASH

4Mbit

IC5

PROGRAM

(TAM Model)

REG

3.3V

MODEM

3.3V

LINERX

LINE

+5V

IC4

IC2

IC6

Transformer

REG

BOA

LINETX

Relay

+3.3

RESET

THERMAL

ANALOG

HEAD

24MHz

CPC

2 strobe

+24V

(Not Used)

OSC

32.256MHz

IC10

OP-PANEL

CPU

FET

THON

I/F

TONE1

MONRX

PRINTER

64Kbit

256kbit

TONE

BUFFER

CONTROL

SRAM

ROM

STB1,2

ASIC

(Not Used)

THLAT,THCLK,

VOL

ACK_EN

+5V

THDAT

IC1

H/SRX

LED ON

IMAGE

H/STX_MUTE

BELL

+24V

A/D

PROCESSING

CLK, SIG

MOTOR

JAM

SERIAL

I/F

RTC

CIS

I/F

HOOK

3.3V chip

PAPER

RLY

IC7

32.768KHz

MOTOR DRIVER

To FLASH

PROGRAMMER

MOTOR

SPEAKER

HANDSET

B-FT937LA-KX

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	DESCRIPTION
			VOLTAGE

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)

					KX-FT937LA-B

NO.	SIGNAL	I/O	POWER SUPPLIED	DESCRIPTION
			VOLTAGE
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

KX-FT937LA-B

	NO.	SIGNAL	I/O	POWER SUPPLIED	DESCRIPTION
				VOLTAGE
	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)

Connection to operation reset circuit

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.

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.

KX-FT937LA-B

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)

KX-FT937LA-B

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

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

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.

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6.5.Sensors and Switches

All of the sensors and switches are shown below.

Sensor Circuit	Sensor	Sensor or Switch Name	Message Error
Location
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

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

6.5.2.Cutter Position Sensor

Digital Board

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

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 (IC1-20	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

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

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

		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

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

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 (IC1-6 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.

+ 146 hidden pages

Panasonic KX-FT937 Service Manual

ORDER NO. KMF0606979CE

Facsimile with Digital Answering System

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