TOSHIBA ft8259 Service Manual

FILE NO. 2B0-9906

SERVICE MANUAL

CORDLESS TELEPHONE

FT-8259

PUBLISHED IN JAPAN, Sep., 1999

CONTENTS

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

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

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

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

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

TROUBLESHOOTING HINTS ................................................................................................... 14

IC AND TRANSISTOR VOLTAGE CHART ............................................................................... 23

SEMICONDUCTOR LEAD IDENTIFICATION........................................................................... 29

ELECTRICAL PARTS LOCATION............................................................................................. 32

WIRING DIAGRAMS .................................................................................................................35

EXPLODED VIEW AND MECHANICAL PARTS LIST............................................................... 38

PARTS LIST............................................................................................................................... 42

ASSEMBLY PARTS LIST .......................................................................................................... 58

SPECIFICATIONS ..................................................................................................................... 59

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 b uilt into the instrument by the manu facture
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 indentified 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.

1

OPERATING CONTROLS

HANDSET CONTROLS AND FUNCTIONS

ANTENNA

LINE 2 LED (Orange)
LINE 1 LED (Green)
TALK/BATT LOW LED (Red)
TALK button
TONE button

FLASH/RDL
(Flash/Redial) button

PAUSE button

• While the handset is engaged in a
call on an outside line, pressing the
MEM and PAUSE buttons
continuously prevents someone
from picking up your conversation
on the base unit.

MEM (Memory) button

900

MHz

2LINE

TALK

LINE1 LINE2

BATT LOW

TALK

LINE2

LINE1

ABC DEF

123

GHI JKL MNO

456

PQ

789

RS

TONE

FLASH/RDL INTCOMCHVOL/RING

MEM

-

PRIVACY-2

1

PAUSE

TUV

OPER

0

CONF HOLD

WX
YZ

LINE 1 button
LINE 2 button

Dialpad (0~9, and # buttons)
INTCOM button
CH (Channel) button
VOL/RING
(Volume/Ringer volume)button

HOLD button
CONF (Conference) button

Charging Contacts

BASE UNIT CONTROLS AND FUNCTIONS

DC in 9V Jack
TEL LINE 2 jack
TEL LINE 1/2 jack

MEM (Memory) button
PAUSE button

• While the base unit is engaged in a
call on an outside line, pressing the
MEM and PAUSE buttons
continuously prevents someone
from picking up your conversation
on the handset.

CORDLESS TELEPHONE FT8259

SPEED DIAL INDEX

Battery compartment

T-P(TONE-PULSE) Switch
Line 1 ringer volume switch
Line 2 ringer volume switch

900MHz 2 LINE

Speaker
One-touch dialing keys (1 to 8)

MUTE button

SPEED DIAL INDEX

1

2
34
56
78
90

OPEN

TONE button
FLASH/RDL (Flash/Redial)
button

LINE 2 LED (Orange)
LINE 1 LED (Green)

LINE 1 button
LINE 2 button

CHARGE LED
POWER LED

ABC DEF

123

GHI JKL MNO

456

PQ

78

RS

TONE

FLASH/RDL

LINE1 LINE2

900

TUV

OPER

CONF HOLD

MHz

CHARGE
POWER

0

2 LINE

WX
YZ

2

ANTENNA

MEM

1

PRIVACY

PAUSE

2

MUTE

9

INTCOM

SPEAKER

INTCOM LED (Green)
INTCOM button

SPEED DIAL INDEX
Speaker volume control

HOLD button
CONF (Conference) button

SPEAKER LED (Green)
SPEAKER button

Microphone

ALIGNMENT PROCEDURE

Base Unit

Transmitter Section

Connections

Power

Meter

Frequency

Counter

Deviation

Mater

RF
Test Point

RF
Test Point

BASE Unit

J4
DC IN
9V Jack

TEL Line

Jack

J1

1kHz 77.5mV

AF GEN.

AC

Adapter

AC 120V
60Hz

Preset

a) Connect the base RF unit to the base main unit.
b) Connect the AC adapter to the base unit while pressing the “ ∗ ” and “ # “ keys and keep pressing it continuously

for approximate 1 second.
c) Release the keys when entering TEST mode with beep.
d) Press “1” key to enter the TEST mode 1.

Alignment Procedure

step

1

2

3

Adjustment

RT301

(TX P ower)

CT1

(TX Frequency)

RT2

(TX Modulation)

Remarks

Connect the Po w er Meter to the RF test point on the Base MAIN PCB.
Adjust RT301 for a -5.0dBm 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 “2” 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 77.5 mV from the AF Generator .
Connect the Deviation Meter to the RF test point on the Base MAIN PCB.
Adjust RT2 to indicate ±8 kHz De v.

Alignment Point Location on Base Main PCB and Base RF PCB

Base Main PCB

Base RF PCB

3

J1
TEL LINE Jack

J4
DC IN 9V Jack

T

S1
T/P Switch

P

RF Test Point

Receiver Section

Connections

RF SG

­+

RF
Test Point

TEL Line

Jack

J1

Dummy Load

(600-ohm)

­+

AC V oltmeterBASE Unit

AC 120V

60Hz

AC

Adapter

DC IN 9V Jack

J4

AF
Terminal

DC V oltmeter

Preset

a) Connect the base RF unit to the base main unit.
b) Connect the AC adapter to the base unit while pressing the “ ∗ ” and “ # “ keys and keep pressing it continuously

for approximate 1 second.

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

Alignment Procedure

step

Preset to

1

SG: 1mV

No modulation

SG: 1mV

1 kHz ±8kHz

2

deviation

SG: -7.0 dB

1kHz ±8kHz

3

Deviation

Adjustment

L183

(Discriminator

Voltage)

(RX AF

Voltage)

µµ

µV

µµ

RT181

(SQ Point)

RT1

Remarks

Press the “4” key 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 903.002467 MHz.
Connect the DC Voltmeter to the AF test point. Adjust L183 to indicate DC

0.95 V.
Connect the AC Voltmeter across a 600-ohm dummy to the Telephone Line

Jack. Adjust RT1 for a 220 mV reading on the AC voltmeter.
Press the “5” key to enter the TEST Mode 5. Make sure that the

frequency of RF SG output is 903.002467 MHz. Adjust RT181 to turn to
the point where the INTCOM LED just turns on.

Alignment Point Location on Base Main PCB and Base RF PCB

Base Main PCB

AF Test Point

4

J1
TEL LINE Jack

J4
DC IN 9V Jack

T

S1
T/P Switch

P

RF Test Point

Handset Unit

Transmitter Section
Connection

Power

Meter

Frequency

Counter

Deviation

Mater

Preset

a) Connect the handseet RF unit to the handset main unit.
b) Connect DC power supply to battery connector on the handset unit.
c) Turn the DC power supply On while pressing " *" and " # " keys, and keep pressing the keys continuously for

approximate 1 second.
d) Release keys when entering TEST mode 1 with TALK LED and LINE2 LED lighting and beep.

RF
Test Point

RF
Test Point

HANDSET Unit

J603
Battery
Connector

MIC+Pin

DC 3.8V

AF GEN.

1kHz 11mV

DC Power Supply

Alignment Procedure

step

1

2

3

Adjustment

RT501

(TX P ower)

CT601

(TX Frequency)

RT603

(TX Modulation)

Remarks

Connect the RF power Meter to the RF test point on the handset MAIN PCB.
Adjust RT501 for a -6.5dBm 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 903.102467 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 11mV from the AF
Generator.
Connect the Deviation Meter to the RF test point on the handset MAIN PCB.
Adjust RT603 to indicate ±8 kHz De v.

Alignment Point Location on Handset Main PCB and Handset RF PCB

Handset PCB

RF PCB

RF Test Point

5

Receiver Section

Connections

RF SG

­+

RF
Test Point

SP

Terminal

Dummy Load

(150-ohm)

­+

AC V oltmeterHANDSET Unit

DC Power Supply

Battery

Connector

DC 3.8V

J603

AF
Test Point

DC V oltmeter

Preset

a) Connect the handset RF unit to the handset main unit.
b) Connect DC power supply to battery connector on the handset unit.
c) Turn the DC power supply ON while pressing “

” and “ # ” keys, and keep pressing the keys continuously for

*

approximate 1 second.

d) Release keys when entering TEST mode 1 with TALK LED and LINE2 LED lighting and beep.

Alignment Procedure

step

Preset to

1

SG: 1mV

No modulation

SG: 1mV

1 kHz ±8kHz

2

deviation

SG: -7.0 dB

1kHz ±8kHz

3

Deviation

Adjustment

L603

(Discriminator

Voltage)

RT602

(RX AF

Voltage)

µµ

µV

µµ

RT601

(SQ Point)

Remarks

Press the “4” key to enter the TEST Mode 4. Connect the RF Singal
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 AF test point. Adjust L603 to indicate
DC 0.85V.

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 V oltmeter across a 150-ohm dumm y to the SP Connector.
Adjust RT602 for a 150 mV reading on the AC Voltmeter.

Press the “5” k e y to enter the TEST Mode 5. Mak e sure that the frequency
of RF SG output is 926.997467 MHz. Adjust RT601 to turn to the point
where the LINE1 LED just turns on.

Alignment Point Location on Handset Main PCB and Handset RF PCB

Handset PCB

AF Test Point

RF PCB

6

RF Test Point

Base Unit

BLOCK DIAGRAMS

7

Handset

8

Base Unit, Main

SCHEMATIC DIAGRAMS

9

10

Base Unit, Key

11

Handset

12

13

TROUBLESHOOTING HINTS

1. The bell does not ring.

When the INTCOM key of the
base is pressed, does the
ringer on the handset ring?

OK

When the TEL SG is joined
with the base to make bell
signal, is there pulse wave at
pin 4 of IC5 (Line1) or IC13
(Line2) ?

OK

Is there pulse wave at
pin 38 (Line1) or pin 39
(Line2) of IC14?

OK

Check IC14 and its
peripheral circuit.

NG

NG

NG

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

Check IC5 (Line1) or IC13
(Line2) and TEL network
circuit.

Check R58, C45 and R59.

14

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

Can the base and handset be
connected?

OK

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

OK

When the INTCOM key of
the base is pressed, does
pin 29 of IC14 change from
low to high?

NG

NG

NG

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 IC603 be seen?

OK

At the Q605 collector, can the
pulse wave be seen?

OK

Check RINGER Y601.

Check key rubber.

NG

NG

Check IC603.

Check R688, R627 and
D604.

OK

Check IC14 and its peripheral
circuit.

15

3. The base and handset cannot be connected.

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

OK

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

OK

Set the base in the test
mode 3, check whether
deviation of the TX data
is app. 8 kHz Dev.

OK

Set the base in the test
mode 8, 903.002467
MHz (250 Hz ±8 kHz
Dev.) 1mV output signal
from RF jack is applied.
Can the INTCOM LED
be lighted?

OK

NGACheck IC14 and its

peripheral circuit.

NG

Check base RF unit.

Check whether there is a

NG

250 Hz data wavef orm at
“MOD” of RF unit.

OK

Check base RF unit.

NG Check whether there is a

250 Hz data wavef orm at
pin 9 of IC181.

OK

Check whether there is a
250 Hz data wavef orm at
the Q3 collector.

OK

Check RT2, R69, R70,

NG

R71, R72, R115, C56
and C84.

Check IC181, Q181 and

NG

their peripheral circuit.

Check RT1, Q3 and their

NG

peripheral circuit.

OK

NG

Check base RF unit.

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

OK

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

OK

Check whether there is a
250 Hz data wavef orm at
pin 54 of IC14.

OK

Check IC14 and its
peripheral circuit.

NG Check IC603 and its

peripheral circuit.

NG

Check handset RF unit.

Check R261, IC4 and

NG

their peripheral circuit.

16

A

Set the handset in the
test mode 3, check
whether deviation of the
TX data is app. 8 kHz
Dev.

OK

Set the handset in the
test mode 6, 926.997467
MHz (250 Hz ±8 kHz
Dev.) 1mV output signal
from RF jack is applied.
Check whether the bell
ring.

OK

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

NG Check whether there is a

250 Hz data wav eform at
“MOD” of RF unit.

OK

Check handset RF unit.

Check whether the 250

NG

Hz data waveform from
pin 9 of IC606 is fed.

OK

Check whether there is a
250 Hz data wavef orm at
the Q601 collector.

OK

Check whether there is a
250 Hz data wavef orm at
pin 55 of IC603.

OK

Check RT603, R619,

NG

R632, R634, R635,
R636 and C610.

Check IC606, Q612 and

NG

their peripheral circuit.

Check RT602, Q601 and

NG

their peripheral circuit.

Check R696, R600,

NG

R621, R624, Q602,
IC607 and their
peripheral circuit.

OK

NG

Check handset RF unit.

Check IC603 and its
peripheral circuit.

17

4. Cannot make a phone call (pulse).

Can the base and handset
be connected?

OK

While in TALK MODE, press
dial key of the handset.
Check whether square wav e­form from pin 89 (Line1) or
pin 90 (Line2) of IC14 is fed.

OK

Check Q4, RL1, R58 (Line1)
or Q12, RL2, R126 (Line2)
and their peripheral circuits.

NG

NG

See 3. The base and handset
cannot be connected.

Check IC5.

5. Cannot make a phone call (tone).

Can the base and handset be
connected?

OK

NG

See 3. The base and handset
be cannot be connected.

While in TALK MODE, press
dial key of the handset.
Can tone waveform from Pin
14 of IC11 is fed?

OK

Can tone signal be heard
from the handset speaker?

OK

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

NG

NG

Check IC5 and IC14.

Check IC4, IC2, IC3, Q2
(Line1) or IC8, IC9, Q10
(Line2) and their
peripheral circuits.

18

6. Voice cannot be transmitted to other party (outgoing call).

Can the base and handset be
connected?

OK

The 1 kHz, 11mV sine
waveform is applied to

+

MC601
sine waveform from pin 24 of
IC607 be fed?

Check whether there is the
1 kHz sine waveform at
pin 20 of IC607.

Check whether there is the
1 kHz sine waveform at
MOD terminal.

TX output signal from the
handset is detected by the
liner detector, can the 1 kHz
sine waveform be fed?

side, can the 1 kHz

OK

OK

OK

OK

NG

NG

NG

NG

NG

See 3. The base and handset
cannot be connected.

Check Q608 and its
peripheral circuit.

Check IC607 and its
peripheral circuit.

Check RT403 and its
peripheral circuit.

Check handset RF unit.

Check whether there is the
1 kHz sine wave f o rm at pin 9
of IC181 on the base unit.

OK

Check whether there is the
1 kHz sine wave f o rm at pin 3
of IC4.

OK

Check whether there is the
1 kHz sine waveform at
pin 6 of IC4.

OK

Check whether there is the
1 kHz sine waveform at the
Q2 (Line1) or Q10 (Line2)
collector.

OK

Check whether the 1 kHz sine
waveform from TEL-line
output is fed.

OK

NG

NG

NG

NG

NG

Check IC181, Q181 and
their peripheral circuit.

OK

Check RT1, Q3 and their
peripheral circuits.

Check IC4 and its
peripheral circuit.

Check IC2, IC3, Q2 (Line1)
or IC6, IC9, Q10 (Line2) and
its peripheral circuit.

Check T1, RL1 (Line1) or T2,
RL2 (Line2) and their
peripheral circuits.

NG

Check base RF unit.

Check MC601 of handset.

19