TOSHIBA FT-3808BK Service Manual

Teléfonos

Precauciones de seguridad Controles de operación

FT-3808BK

Procedimiento de ajuste Diagramas a bloques Diagramas esquemáticos Consejos para localización de fallas Tablas de frecuencias Tablas de voltajes en transistores e ICs Identificación de terminales en semiconductores Localización de partes eléctricas Diagramas de alambrado Vistas explotadas y lista de partes eléctricas Lista de componentes Lista de partes de empaque Especificaciones

FILE NO. 2B0-9805

SERVICE MANUAL

CORDLESS TELEPHONE

FT-3808BK

PRINTED IN CHINA, JUNE,1999

SAFETY PRECAUTIONS-------------------------------------------------------------------------- 1 OPERATING CONTROLS ------------------------------------------------------------------------ 2 ALIGNMENT PROCEDURE --------------------------------------------------------------------- 4 BLOCK DIAGRAM ------------------------------------------------------------------------------- 11 SCHEMATIC DIAGRAMS ---------------------------------------------------------------------- 13 TROUBLESHOOTING HINTS ------------------------------------------------------------------ 15 FREQUENCY CHART ---------------------------------------------------------------------------- 21 IC AND TRANSISTOR VOLTAGE CHART ------------------------------------------------- 22 SEMICONDUCTOR LEAD IDENTIFICATION --------------------------------------------- 28 ELECTRICAL PARTS LOCATION ------------------------------------------------------------ 30 WIRING DIAGRAMS -----------------------------------------------------------------------------32 EXPLODED VIEW AND MECHANICAL PARTS LIST ---------------------------------- 34 COMPONENT LIST -------------------------------------------------------------------------------38 PACKING PARTS LIST---------------------------------------------------------------------------54 SPECIFICATIONS ---------------------------------------------------------------------------------55

SAFETY PRECAUTIONS

Before returning any TOSHIBA FT-3808BK 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 component 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 ! in the schematic diagram and the parts list. Before replacing 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.

OPERATING CONTROLS

5 6

MAIN FEATURES ON HANDSET

1. Helical Antenna - Durable high -gain helical antenna.

2. TALK / FLASH Key & Indicator - Places the handset into talk mode when used away from the base unit/Access Services such as Call Waiting and Call Forwarding . The indicator lights when the handset is in talk mode.

3. BATT LOW & Indicator - Blinks on and off when the handset battery needs to be charged.

4. CHANNEL CHANGE - Switch to a new channel during conversation.

5. OFF Key - Places the handset into standby mode.

6. Volume H/L Control - Control the loudness of the receiver.

7. Dialing Keys - Used for dialing numbers, storing numbers in memory.

8. TONE - Temporary set the telephone into TONE mode.

9. PROGRAM - Used when storing numbers in the memory.

10. REDIAL - Redial the last number dialed.

11. MEMORY - To dial a number from memory.

12. Charging Contacts - Provides power to charge the handset when it is placed on the base unit.

13. BATTERY PACK (BACK)

DC 9V

REAR SIDE OF BASE UNIT

TEL.LINE

BACK SIDE OF BASE UNIT

SPEED DIAL INDEX

1 2 3 4 5

6 7 8 9 0

5 6

MAIN FEATURES ON BASE UNIT

1. Phone Cord Jack -Plugs one end of the telephone line cord into standard RJ11C telephone line jack and the other end into this jack for connecting the base unit to the telephone line.

2. Antenna - Durable high-fain rod antenna.

3. SPARE BATT Indicator - Illuminates steadily when a battery is placed in the base unit charge cradle.

4. IN-USE Indicator - Illuminates when handset is off hook (line engaged).

5. CHARGE Indicator - Goes on when the handset is in the cradle and the battery is charging.

6. POWER Indicator - Illuminates when power is applied to base unit.

7. Memory Dialing cord - Memeory location recording.

8. PAGE - To page the handset, press page key once. Pressing the PAGE a second time will cancel the page.

9. Charging Contacts - Provides power to charge the handset when it is placed onthe base unit.

10. TONE/PULSE Switch - Set the dialing mode between DTMF and PULSE.

11. POWER ADAPTOR JACK - Insert one of the plugs into the jack.

12. SPARE BATTERY DOOR - Install the spare battery pack.

ALIGNMENT PROCEDURE

Perform the alignment of the Handset & Base using the test mode described below:

1. Test mode for Handset unit:

1.1 Connecting the 3.6VDC power supply to the battery contact.

1.2 Pressing the “#” and “3” keys at the same time, both “IN_USE LED” and “LOW_ BATT LED” will be on.

1.3 To change channel, press the CHANNEL key.

1.4 To toggle TX power , press the PROG key.

1.5 To toggle RX power, press the MEM key.

1.6 To toggle TX attenuater, press the REDIAL key.

1.7 To change PLL gain mode, lowest (4 steps) Õ highest, Press the PHONE key.

1.8 Pressing OFF key to exit from test mode.

1.9 LED indication.

IN USE LED “ON” LOW BATT LED “ON” TX power on RX Power on

2. Test mode for Base unit:

2.1 Apply AC power by connecting the AC adaptor to Base unit, The POWER LED will illuminate.

2.2 Pressing and hold the PAGE button, then, slide the TONE/PULSE switch from PULSE to TONE to enter test mode, The IN_USE LED and the CHARGE LED will illuminate.

2.3 Change Mode:

Press and hold the PAGE button for 1-2 seconds. You will change to the next mode. once the charge LED change state (1Õ 0 or 0 Õ 1).

MODE Charge LED Function Press PAGE button

1 ON Change RF channel 0-9 (default 5) 2 OFF Toggle RF transmitter power Default on 3 ON Unused 4 OFF Generate single tone from

DTMF table for 3 seconds, There are 8 tones in the table.

697, 770, 852, 941, 1209, 1336, 1477, 1633 Hz default is 697Hz.

3. Handset unit :

RX -Loop-V TX-Loop-V RX-Audio

Audio

Frequency

3.1 Test equipment required and connection.

Digital Voltmeter

Generator

MIC IN / Handset unit RX Audio (RF & Audio Board) TX Audio / REC + Batt. ANT

3.6V

Counter

3.2 Preparation from alignment

Place the H/S Board into test mode, disconnect microphone wire at H/S Board and set the volume to “L” position.

3.3. Alignment procedure :

Step Preset Adjustment Remark

1 H/S Board into test

mode ---

Connect the digital voltmeter to the PCB test point RX-Loop-V. The reading should > 0.25V DC and < 2.45V DC.

2 H/S Board into test

mode ---

Connect the digital voltmeter to test point TXLoop -V. The reading should > 0.25V DC and <

2.45V DC.

3 H/S Board into test

mode

4 H/S Board into test

mode

5 Audio Gen : 1KHz,

-20dB (NO Load)

6 Audio Gen : 1KHz,

-40dB (NO Load)

HC92 Connect the digital voltmeter to test point RX-A.

Adjust for 1.17VDC at CH6.

HC87 Connect the Frequency counter to test point ANT.

Adjust for 926.55MHz at CH6.

HR113 Connect the VTVM to test point REC + Adjust for

-35dB

HR119 Connect the VTVM to test point TX Audio.

Adjust for -16dB.

VTVM

4. Base unit :

RX -Loop-V TX-Loop-V RX-Audio

Audio

Frequency

4.1 Test Equipment required and connection.

AC Power supply : 120V 50Hz

Digital Voltmeter

Generator

Quad-Tune / Base unit Pin3 of BT1/ Pin3 of BT1 (RF & Audio Board) Tx Audio TX Audio / REC + 9V DC IN ANT

Adapter

Counter

4.2. Preparation from alignment Place the Base Board into test mode.

4.3. Alignment procedure :

Step Preset Adjustment Remark

1 Base Board into test

mode ---

Connect the digital voltmeter to the point RXLoop -V. The reading should >0.25V DC and <2.45V DC.

2 Base Board into test

mode ---

Connect the digital voltmeter to test point TXLoop -V. The reading should > 0.25V DC and <

2.45V DC.

3 Base Board into test

mode

4 Base Board into test

mode

5 Audio Gen : 1KHz,

-10dB (NO Load)

6 Audio Gen : 1KHz,

-30dB (NO Load)

BC151 Connect the digital voltmeter to test point Quad-

tune. Adjust for 2.2VDC at CH6.

BC92 Connect the Frequency counter to test point ANT.

Adjust for 903.8MHz at CH6.

BR114 Connect the VTVM to test point PIN 3 of T1

Adjust for -10dB

BR135 Connect the VTVM to test point TX Audio.

Adjust for -26dB.

VTVM

Base Unit Audio Block Diagram

BLOCK DIAGRAM

Tx Filter

Tx-Audio

Rx-Audio

Tx Filter

TA31103F

RSSI

RF Control

Audio Power(s)

Handset Audio Block Diagram

RF Powers

Summing Amp

Pre-amp

Tx Data

Rx Data

Tx Mute

Rx Mute

MCU

Power

Control

Compressor

Expandor

EFPROM

ATE

interface

DTMF

D/A Circuit

Speech

Network

Speech

Network

Telephone Line

Isoiation Boundary

Cradie Contacts Battery

Tx-Audio

Rx-Audio

RSSI

RF Control

Tx Filter

Data Filter

Audio Power (s)

RF Power (s)

Summing Amp

Pre-amp

Tx Data

Rx Data

Tx Mute

Rx Mute

MCU

Power

Control

Compressor

Expandor

Keypad

EFPROM

ATE

interface

TA31103F

Pre-amp

Ringer

Cradie Contacts Battery

Microphone

Receiver

RF module Block Diagram

2 POLE CERAMIC

Ist Rx AMP

1 GHz LOW PASS

SAW FILTER

TX O.P AMP

TX L.O.

TX Audio

2nd Rx AMP

V-Tune

MIXER

Fin

DUAL PRESCALER SYNTHESIZER

3 LINE DATA

10,7 MHz CERAMIC

Fin

4.0 MHz REFERENCE

IF AMP

V-Tune

Rx L.O.

10.7MHz CERAMIC

V-Tune

Rx-AUDIO

RX DATA

RSSI

TROUBLESHOOTING HINTS

When the PAGE SW of the base is pressed, does the ringer

Check TEL network primary

1. The bell does not ring.

on the handset ring?

When the TEL SG is joined with the base to made bell signal, does PIN 4 of BU8 change from high to low.

By using voltmeter check BU3 of base.

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

By using voltmeter check BU8.

circuit.

BU3 is defective.

BU8 is defective.

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

Can the base and

Check whether the base &

By using voltmeter, check the base & Check the base TX data

Check the handset RX

Check RX data pulse wave

When the key of the

Press handset Dial Key

Check the BU3 and the

Check the handset RX RF

When the PAGE SW of

Check the BS3, BR154 and

handset be connected.

NG NG

handset RX and TX-Loop-V are OK.

Check the base TX Power

OK OK NG

deviation

Sensitivity

on RX-DATA

NG NG

while in Talk Mode, Can key touch sound be heard from the ringer.

handset is pressed, can the pulse output at PIN20 of HU3.

NG OK

At the HD6 anoe, Can the pulse wave be seen.

handset PLL circuit (B/HU2 and surrounding circuit of B/HU2)

By using voltmeter, check the base TX circuit.

By using voltmeter, check BU5 and BU6

circuit (HU1) as well as well as HQ2 and HQ4.

Check HU5C and surrounding circuit of HU5

Check HU3 circuit.

Check HQ14, HQ17 and

HR139.

the base is pressed, does PIN21 of BU3 change from high to low.

surrounding circuit of BU3.

Ringer is defective.

BR77.

+ 42 hidden pages

TOSHIBA FT-3808BK Service Manual

CONTENTS

SAFETY PRECAUTIONS

OPERATING CONTROLS

ALIGNMENT PROCEDURE

TROUBLESHOOTING HINTS