Toshiba FT 8801A Service Manual
FILE NO. 2BO-200112
SERVICE MANUAL
CORDLESS TELEPHONE
FT-8801A
PUBLISHED IN JAPAN, Sep., 2001
CONTENTS
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
T
ALK
PAUSE
ABC
TUV
OPER
DEF
2
MNO
JKL
5
8
0
FUNC
1
GHI
4
PQ
RS
7
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
#
CH
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
RF
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
J1
1kHz -11dBm
AF GEN.
AC
Adapter
AC 120V
60Hz
Alignment Procedure
Step
1
2
3
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
AC
Adapter
RF
Test Point
+
DC IN 9V Jack
Dummy Load
(600-ohms)
J1
TEL Line
J2
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
1
(−47dBm)
No modulation
SG: 1mV
2
(−47dBm)
1 kHz ±8kHz
Deviation
SG: −6.0 dBµV
3
(−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
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
1
2
3
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
SP
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
1
(−47dBm)
No modulation
SG: 1mV
2
(−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
3
(−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?
OK
When the TEL SG is joined
with the base to make bell
signal, is there pulse wave at
Pin 4 of IC3?
OK
Is there pulse wave at
Pin 21 of IC6?
OK
Check IC6 and its
peripheral circuit.
NG
NG
NG
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.
3)
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?
OK
Press handset DIAL key
while in TALK MODE.
Can key touch sound be
heard from the ringer?
OK
When the PAGE SW of the
base is pressed, does
Pin 20 of IC6 change from
high to low?
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 IC608 be seen?
OK
At the Q612 collector, can the
pulse wave be seen?
OK
Check RINGER Y601.
Check R127, R135 and S1.
NG
NG
Check IC608.
Check R715, R726, R727,
R728, R730, Q612 and Q613.
OK
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.
OK
Check the TX POWER
and the TX FREQUENCY
on the base unit.
OK
Press PAGE key twice,
check whether deviation
of the TX data is app. 8
kHz Dev.
OK
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?
OK
NGACheck IC6 and its
peripheral circuit.
Check RT1, Q4, IC1 and
NG
their peripheral circuits.
NG Check whether there is a
250 Hz data waveform at
C168.
OK
Check D8, IC1 and
their peripheral circuits.
NG Check whether there is a
250 Hz data waveform at
Pin 9 of IC4.
OK
Check whether there is a
250 Hz data waveform at
Pin 3 of IC2.
OK
Check RT2, R98,
NG
R122, R123, R125,
R126, C92 and C147.
Check IC1, FT2 and
NG
the peripheral circuit of
IC4.
Check RT4 and its
NG
peripheral circuit.
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 waveform at
Pin 34 of IC6.
Check IC6 and its
peripheral circuit.
Check IC608 and its
NG
peripheral circuit.
Check RT601, Q602,
NG
IC601 and their
peripheral circuits.
OK
NG
— 15 —
Check R78, R79, IC2
and their peripheral
circuits.
A
Press 3 key, check
whether deviation of the
TX data is app. 8 kHz
Dev.
OK
Press 6 key,
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 waveform at
RT602.
OK
Check IC601, D603, and
their peripheral circuits.
Check whether the 250
NG
Hz data waveform from
Pin 9 of IC603 is fed.
OK
Check whether there is a
250 Hz data waveform at
Pin 3 of IC602.
OK
Check whether there is a
250 Hz data waveform at
Pin 55 of IC608.
OK
Check RT602, R668,
NG
R712, R713, R716, R717,
C719 and C748.
NG
Check IC601, FT602 and
their peripheral circuits of
IC603.
Check RT603 and its
NG
peripheral circuit.
NG
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?
OK
While in TALK MODE, press
dial key of the handset.
Check whether square
waveform from Pin 13 of IC6
is fed.
OK
Check Q12, RL1 and their
peripheral circuits.
NG
NG
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?
OK
NG
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?
OK
Can tone signal be heard
from the handset speaker?
OK
Check the base TEL-line
circuit and REPLAY
control circuit.
NG
NG
Check IC6.
Check IC2, Q3 and their
peripheral circuits.
— 17 —
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