CORDLESS TELEPHONE
PUBLISHED IN JAPAN, Oct., 2000
SERVICE MANUAL
FILE NO. 2B0-200011
SG-1600,1800
The difference between Models
SG-1600 and SG-1800 is only in model name so that
the parts concerned to the model are different. All other
parts in mechanical and electrical are the same.
Please refer to the contents for details.
1
CONTENTS
SAFETY PRECAUTIONS ............................................................................................................ 1
OPERATING CONTROLS ........................................................................................................... 2
ALIGNMENT PROCEDURE ........................................................................................................ 3
BLOCK DIAGRAMS ..................................................................................................................... 5
SCHEMATIC DIAGRAMS ............................................................................................................ 7
TROUBLESHOOTING HINTS ................................................................................................... 13
IC AND TRANSISTOR VOLTAGE CHART ............................................................................... 19
SEMICONDUCTOR LEAD IDENTIFICATION ........................................................................... 25
ELECTRICAL PARTS LOCATION ............................................................................................. 27
WIRING DIAGRAMS .................................................................................................................29
EXPLODED VIEW AND MECHANICAL PARTS LIST ............................................................... 33
PARTS LIST ............................................................................................................................... 37
ASSEMBLY PARTS LIST .......................................................................................................... 55
SPECIFICATIONS ..................................................................................................................... 56
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 manufacture
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.
2
OPERATING CONTROLS
HANDSET CONTROLS AND FUNCTIONS
BASE UNIT CONTROLS AND FUNCTIONS
D
IG
IT
A
L
C
A
L
L
E
R
ID
C
O
R
D
L
E
S
S
T
E
L
E
P
H
O
N
E
S
G
-1
8
0
0
IN USE
/CHARGE
PAGE
DIGITAL SPREAD SPETRUM
2.4GHz
CID
2.4GHz
MEM
VOL
CID
FLASH
TALK
ABC
2
JKL
5
TUV
8
OPER
0
DEF
3
MNO
6
WX
YZ
PQ
RS
9
#
GHI
4
7
1
RDL/P
TONE
FUNCTION
CHANNEL
SELECT DELETE
L.D.
LOCAL
TALK Button
TONE/
(TONE)Button
MEM (Memory) Button
RDL/P (Redial/Pause)Button
Charging contact
PULSE/TONE Switch
DC IN 9V Jack
TEL LINE Jack
Antenna
IN USE/CHARGE LED
PAGE Button
Charging Contact
DELETE Button
SELECT Button
FLASH Button
CID (Caller ID) Button
Dialpad
Rechargeable
Battery Pack(back)
Headset jack
FUNCTION Button
# (
)Button
(Right arrow button)
CHANNEL Button
LOCAL/3 Button
VOL (Volume/Ringer
) Button
(Up arrow button)
VOL (Volume/Ringer
) Button
(Down arrow button)
ANTENNA
L.D./1 Button
(
)Button(Left arrow button)
Hook
LCD
Number of calls
Dot matrix display
Date
Time
Caller's telephone number
Caller's name
3
ALIGNMENT PROCEDURE
Base Unit
Transmitter Section
Test Equipment Required and Connections
Preset
a) Set T/P SW to pulse mode.
b) Turn on AC power while the "PAGE" key is being depressed.
Alignment Procedure
Alignment Point Location on Base Main PCB and Base RF PCB
· Spectrum Analyzer
· Oscilloscope
Test Point
(J251)
RF PCB
TP307
AC Adapter
(120V 60Hz)
Base Unit
Spectrum Analyzer
Oscilloscope
Handset
Frequency Counter
DET terminal
GND
step
1
2
3
Adjustment
CT1
(Frequency Adjust)
RT251
(Power Adjust)
RT351
(Deviation Adjust)
Remarks
Connect the Frequency Counter to test point (TP307).
Adjust CT1 so that the frequency is 6.144 MHz.
Connect the Spectrum Analyzer to JACK (J251).
Adjust RT251 so that the power instructions of the Spectrum analyzer
reaches +11.0 dBm.
Press the PAGE key once.
Set the Handset to the test mode (refer to the next page) and press the "4"
key. Press the CHANNEL KEY 2 times. Connect the oscilloscope to DET
terminal of the Handset.
Adjust RT351 to indicate 520 mVp-p on the oscilloscope.
· Frequency Counter
J2
CT1
BASE RF PCB
RT251
RT351
J251
J1
S2
Base Main PCB
TP307
TP309
DET terminal
ANT JACK
4
CT601
RT851
RT751
Handset Unit
Transmitter Section
Test Equipment Required and Connections
Alignment Point Location on Handset Main PCB and Handset RF PCB
Preset
a) Turn the power ON (Connect battery) while depressing "
" and "#" keys.
b) Press "1" key.
c) Before alignment, be sure to remove solder on the pattern (refer to the illust. below).
Alignment Procedure
Handset Main PCB
· Spectrum Analyzer
· Oscilloscope
Test Point
(J751)
Handset Unit
Spectrum Analyzer
BASE UNIT
Oscilloscope
DET terminal
GND
TP601
Frequency Counter
DET terminal
Alignment Point Location on Handset Main PCB and Handset RF PCB
step
1
2
3
Adjustment
CT601
(Frequency Adjust)
RT751
(Power Adjust)
RT851
(Deviation Adjust)
Remarks
Connect the Frequency Counter to test point (TP601).
Adjust CT601 so that the frequency is 6.144 MHz.
Adjust RT751 so that the power instructions of the Spectrum analyzer
reaches +11.0 dBm.
Press the "2" key.
Set the Base unit to the test mode (refer to the previous page) and press the
PAGE key 3 times. Set T/P SW to TONE mode, and press the PAGE KEY
2times.
Connect the oscilloscope to TP309 of the Base unit.
Adjust RT851 to indicate 520 mVp-p on the oscilloscope.
TP601
· Frequency Counter
Remove solder
before alignment