Toshiba FT 8801A Service Manual

FILE NO. 2BO-200112

SERVICE MANUAL

CORDLESS TELEPHONE

FT-8801A

PUBLISHED IN JAPAN, Sep., 2001

SAFETY PRECAUTIONS ...................................................................................................................... 1

OPERATING CONTROLS .....................................................................................................................2

ALIGNMENT PROCEDURE .................................................................................................................. 3

BLOCK DIAGRAMS ............................................................................................................................... 7

SCHEMATIC DIAGRAMS ...................................................................................................................... 9

TROUBLESHOOTING HINTS ............................................................................................................. 13

IC AND TRANSISTOR VOLTAGE CHART ......................................................................................... 20

SEMICONDUCTOR LEAD IDENTIFICATION ..................................................................................... 24

ELECTRICAL PARTS LOCATION ...................................................................................................... 27

WIRING DIAGRAMS............................................................................................................................ 29

EXPLODED VIEW AND MECHANICAL PARTS LIST ........................................................................ 31

PARTS LIST......................................................................................................................................... 33

ASSEMBLY PARTS LIST ....................................................................................................................47

SPECIFICATIONS ............................................................................................................................... 48

SAFETY PRECAUTIONS

Before returning any models to the customer, a safety check of the entire instrument should be made.

The service technician must be sure that no protective device built into the instrument by the manufacturer has become defective or inadvertently degraded during servicing.

1. WARNING:

Alterations of the design or circuitry of these models should not be made. Any design changes or additions such as, but not limited to, circuit modifications, auxiliary speaker

jacks, switches, grounding, active or passive circuitry, etc. may alter the safety characteristics of these models and potentially create a hazardous situation for the user.

Any design alterations or additions will void the manufacturer’s warranty and will further relieve the

manufacturer of responsibility for personal injury or property damage resulting therefrom.

2. PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this chassis have special characteristics. These characteristics

often pass unnoticed and the protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts that have these special safety characteristics are identified in this manual and its supplements; electrical components having such features are identified by a any of these components, read the parts list in this manual carefully. The use of substitute replacement parts that do not have the same safety characteristics as specified in the parts list may create shock, fire or other hazards.

in the schematic diagram and the parts list. Before replacing

— 1 —

HANDSET CONTROLS

OPERATING CONTROLS

LCD

Antenna

Dot matrix display

LCD Display

VOL/RING Button

REDIAL Button

TALK Button

L.D. Button

(TONE) Button

MEM (Memory) Button

PAUSE Button

Charging contact

BASE UNIT CONTROLS

DC IN 9V Jack

LINE modular Jack

COMPANDOR NOISE REDUCTION

REDIAL FLASH

VOL/ RING

SELECT

ALK

PAUSE

ABC

TUV

OPER

DEF

MNO

JKL

5 8 0

FUNC

GHI

PQ RS

TONE

MEM

CID

LOCALL.D.

WX YZ

DELETE

Number of calls

Date Time

FLASH Button

SELECT Button

Caller's telephone number Caller's name

CID Button

3 6 9 #

LOCAL Button

Dialpad

(PULSE) Button

DELETE CH Button FUNC Button

Rechargeable Battery Pack (back)

SETTING THE DIAL MODE

FLASH

until you hear a

. A confirmation

DIGITAL

CALLER-ID

CORDLESS

TELEPHONE

FT-8801

1 Press and hold

confirmation tone.

2 To set the dial mode for pulse dialing,

press

. Or to set the dial mode for

tone dialing press tone sounds to indicate the setting is complete.

Charging Contact

COMPANDOR NOISE REDUCTION

IN USE

CHARGE

PAG E

— 2 —

Antenna

Cradle

IN USE/CHARGE LED

PAGE Button

ALIGNMENT PROCEDURE

Base Unit

Transmitter Section

Connections

Power

Meter

Frequency

Counter

Deviation

Meter

Test Point

RF Test Point

Preset

a) Connect the AC adapter to the base unit while pressing the “PAGE” key, and keep pressing it continuously for

approximate 2 seconds.

b) Release the “PAGE” key when entering TEST mode 1 with IN USE LED lighting.

BASE Unit

J2 DC IN 9V Jack

TEL Line

Jack

1kHz -11dBm

AF GEN.

Adapter

AC 120V 60Hz

Alignment Procedure

Step

Adjustment

RT1

(TX Power)

CT1

(TX Frequency)

RT2

(TX Modulation)

Connect the Power Meter to the RF test point on the Base MAIN PCB. Adjust RT1 for a -6dBm reading on the Power Meter.

Connect the Frequency Counter to the RF test point on the Base MAIN PCB. Adjust CT1 to make sure that the frequency is 926.897468 MHz.

Press the PAGE key to enter the TEST Mode 2. Connect the AF Generator to the TEL Line Jack on the Base MAIN PCB. Make sure that the output is 1 kHz -11dBm from the AF Generator. Connect the Deviation Meter to the RF test point on the Base MAIN PCB. Adjust RT2 to indicate ±8 kHz Dev.

Alignment Point Location on Base Main PCB

Base Main PCB

Remarks

J1 TEL LINE Jack

J2 DC IN 9V Jack

RT2

CT1

— 3 —

RT1

RF Test Point

Receiver Section Connections

AC VoltmeterBASE Unit

AC 120V

60Hz

RF SG

Adapter

Test Point

DC IN 9V Jack

Dummy Load

(600-ohms)

TEL Line

Jack

AF Terminal

DC Voltmeter

Preset

a) Connect the AC adapter to the base unit while pressing the “PAGE” key, and keep pressing it continuously for

approximate 2 seconds.

b) Release the “PAGE” key when entering TEST mode 1 with IN USE LED lighting.

Alignment Procedure

Step

Preset to

SG: 1mV

(−47dBm)

No modulation

SG: 1mV

(−47dBm)

1 kHz ±8kHz

Deviation

SG: −6.0 dBµV

(−113dBm)

No modulation

Adjustment

L15

(Discriminator

Voltage)

RT4 (RX AF Voltage)

RT3

(SQ Point)

Remarks

Press the PAGE key for 3 times to enter the TEST Mode 4. Connect the RF Signal Generator to the RF test point on the Base MAIN PCB. Make sure that the frequency is 902.952467 MHz. Connect the DC Voltmeter to the Discriminator test point. Adjust L15 to indicate DC 2.10V.

Connect the AC Voltmeter across a 600-ohms dummy to the Telephone

Line Jack. Adjust RT4 for a -11dBm reading on the AC voltmeter.

Press the PAGE key to enter the TEST Mode 5. Make sure that the frequency of RF SG output is 902.952467 MHz. Adjust RT3 to turn to the point where the CHG LED just turns on.

Alignment Point Location on Base Main PCB

Base Main PCB

RT3

RT4

L15

Discriminator Test Point

J1 TEL LINE Jack

J2 DC IN 9V Jack

RF Test Point

— 4 —

Handset Unit

Transmitter Section

Connections

Power

Meter

Frequency

Counter

Deviation

Meter

RF Test Point

HANDSET Unit

J603 Battery Connector

MIC+Pin

AF GEN.

1kHz 9mV

DC Power Supply

DC 3.8V

Preset

a) Connect DC power supply to battery connector on the handset unit. b) Turn the DC power supply on while pressing “ ∗ ” and “ # ” keys, and keep pressing the keys continuously for

approximate 2 seconds.

c) Release keys when entering TEST mode 1 with beep.

Alignment Procedure

Step

Adjustment

RT601

(TX Power)

CT601

(TX Frequency)

RT602

(TX Modulation)

Remarks

Connect the RF power Meter to the RF test point on the handset MAIN PCB. Adjust RT601 for a -5dBm reading on the Power Meter.

Connect the Frequency Counter to the RF test point on the handset MAIN PCB. Adjust CT601 to make sure that the frequency is 903.052467 MHz.

Press the 2 key to enter the TEST Mode 2. Connect the AF Generator to the MIC Connector, make sure that the output is 1kHz 9mV from the AF Generator. Connect the Deviation Meter to the RF test point on the handset MAIN PCB. Adjust RT602 to indicate ±8 kHz Dev.

Alignment Point Location on Handset Main PCB

Handset PCB

J601

MC601

RT602

— 5 —

RF Test Point

RT601

L615

CT601

Receiver Section

Connections

RF SG

DC Power Supply

J601

Battery

Connector

DC 3.8V

RF Test Point

Connector

AF Terminal

Dummy Load

(150-ohms)

DC Voltmeter

AC VoltmeterHANDSET Unit

Preset

a) Connect DC power supply to battery connector on the handset unit. b) Turn the DC power supply on while pressing “ ∗ ” and “ # ” keys, and keep pressing the keys continuously for

approximate 2 seconds.

c) Release keys when entering TEST mode 1 with beep.

Alignment Procedure

Step

Preset to

SG: 1mV

(−47dBm)

No modulation

SG: 1mV

(−47dBm)

1 kHz ±8kHz

Deviation

Adjustment

L615

(Discriminator

Voltage)

RT604

(RX AF

Voltage)

Remarks

Press the 4 key to enter the TEST Mode 4. Connect the RF Signal Generator to the RF test point on the handset MAIN PCB. Make sure that the frequency is 926.997467 MHz. Connect the DC Voltmeter to the Discriminator test point. Adjust L615 to indicate DC 0.85 V.

Connect the RF Signal Generator to the RF test point on the handset MAIN PCB. Make sure that the frequency is 926.997467 MHz. Connect the AC Voltmeter across a 150-ohms dummy to the MIC Connector. Adjust RT604 for 126mV(-18dBV ) reading on the AC Voltmeter.

SG: −6.0 dBµV

(−113dBm)

No modulation

RT603

(SQ Point)

Press the 5 key to enter the TEST Mode 5. Make sure that the frequency of RF SG output is 926.997467 MHz. Adjust RT603 to turn to the point where the Ringer just beeps.

Alignment Point Location on Handset Main PCB

Handset PCB

J601

Discriminator Test Point RF Test Point

RT604

— 6 —

RT603

L615

Base Unit

BLOCK DIAGRAMS

— 7 —

Handset Unit

— 8 —

Base Unit

SCHEMATIC DIAGRAMS

— 9 — — 10 —

Handset Unit

— 11 — — 12 —

TROUBLESHOOTING HINTS

1. The bell does not ring.

When the PAGE SW of the base is pressed, does the ringer on the handset ring?

When the TEL SG is joined with the base to make bell signal, is there pulse wave at Pin 4 of IC3?

Is there pulse wave at Pin 21 of IC6?

Check IC6 and its peripheral circuit.

See 2. The bell does not ring & page does not ring.

Check IC3 and TEL network circuit.

Check R133, R134 and C131.

Deletion of the Caller ID memory

To delete the Caller ID memory in the RAM, proceed with the following process:

Connect the battery with pressing and # buttons, and keep pressing the buttons continuously for

1) approximate 2 seconds.

2) Release buttons when entering TEST mode with beep.

Press CID button.

4) A confirmation beep will sound, then the data for caller ID is deleted. (Note: Do not disconnect the battery until you hear the confirmation beep, otherwise the data may not be completely deleted.)

— 13 —

2. The bell does not ring & page does not ring.

Can the base and handset be connected?

Press handset DIAL key while in TALK MODE. Can key touch sound be heard from the ringer?

When the PAGE SW of the base is pressed, does Pin 20 of IC6 change from high to low?

See 3. The base and handset cannot be connected.

When the key of the handset is pressed, can the pulse output at Pin 58 of IC608 be seen?

At the Q612 collector, can the pulse wave be seen?

Check RINGER Y601.

Check R127, R135 and S1.

Check IC608.

Check R715, R726, R727, R728, R730, Q612 and Q613.

Check IC6 and its peripheral circuit.

— 14 —

3. The base and handset cannot be connected.

Check whether the base is able to set in the test mode 1.

Check the TX POWER and the TX FREQUENCY on the base unit.

Press PAGE key twice, check whether deviation of the TX data is app. 8 kHz Dev.

Press PAGE key 7 times, 902.952467 MHz (250 Hz ±8 kHz Dev.) 1mV output signal from RF jack is applied. Can the IN USE LED be lighted?

NGACheck IC6 and its

peripheral circuit.

Check RT1, Q4, IC1 and

their peripheral circuits.

NG Check whether there is a

250 Hz data waveform at C168.

Check D8, IC1 and their peripheral circuits.

NG Check whether there is a

250 Hz data waveform at Pin 9 of IC4.

Check whether there is a 250 Hz data waveform at Pin 3 of IC2.

Check RT2, R98,

R122, R123, R125, R126, C92 and C147.

Check IC1, FT2 and

the peripheral circuit of IC4.

Check RT4 and its

peripheral circuit.

Check whether the handset is able to set in the test mode 1.

Check the TX POWER and the TX FREQUENCY on the handset unit.

Check whether there is a 250 Hz data waveform at Pin 34 of IC6.

Check IC6 and its peripheral circuit.

Check IC608 and its

peripheral circuit.

Check RT601, Q602,

IC601 and their peripheral circuits.

— 15 —

Check R78, R79, IC2 and their peripheral circuits.

Press 3 key, check whether deviation of the TX data is app. 8 kHz Dev.

Press 6 key,

926.997467 MHz (250 Hz ±8 kHz Dev.) 1mV output signal from RF jack is applied. Check whether the bell ring.

Place the handset on the base to charge about 5 seconds, then connect again.

NG Check whether there is a

250 Hz data waveform at RT602.

Check IC601, D603, and their peripheral circuits.

Check whether the 250

Hz data waveform from Pin 9 of IC603 is fed.

Check whether there is a 250 Hz data waveform at Pin 3 of IC602.

Check whether there is a 250 Hz data waveform at Pin 55 of IC608.

Check RT602, R668,

R712, R713, R716, R717, C719 and C748.

Check IC601, FT602 and their peripheral circuits of IC603.

Check RT603 and its

peripheral circuit.

Check R648, R649, IC602 and their peripheral circuits.

Check IC608 and its peripheral circuit.

— 16 —

4. Cannot make a phone call (pulse).

Can the base and handset be connected?

While in TALK MODE, press dial key of the handset. Check whether square waveform from Pin 13 of IC6 is fed.

Check Q12, RL1 and their peripheral circuits.

See 3. The base and handset cannot be connected.

Check IC6.

5. Cannot make a phone call (tone).

Can the base and handset be connected?

See 3. The base and handset cannot be connected.

While in TALK MODE, press dial key of the handset. Can tone waveform from Pin 1 of IC6 is fed?

Can tone signal be heard from the handset speaker?

Check the base TEL-line circuit and REPLAY control circuit.

Check IC6.

Check IC2, Q3 and their peripheral circuits.

— 17 —

+ 37 hidden pages

Toshiba FT 8801A Service Manual

CONTENTS

SAFETY PRECAUTIONS

OPERATING CONTROLS

ALIGNMENT PROCEDURE

BLOCK DIAGRAMS

SCHEMATIC DIAGRAMS

TROUBLESHOOTING HINTS