Samsung SGH-C120 Service Manual
GSM TELEPHONE
SGH-C120
GSM TELEPHONE
CONTENTS
1. Specification
2. Flow Chart of Troubleshooting
3. Exploded Views and Parts List
4. Electrical Parts List
5. PCB Diagrams
6. Block Diagrams
This Service Manual is a property of Samsung Electronics Co.,Ltd.
Any unauthorized use of Manual can be punished under applicable
International and/or domestic law.
ⓒ
Samsung Electronics Co.,Ltd.
Code No.: GH68-08501A
2005. 11. Rev.1.0
1. SGH-C120 Specification
1-1. GSM General Specification
GSM900
Phase 1
Freq. Band[MHz]
Uplink/Downlink
ARFCN range 1~124
Tx/Rx spacing 45MHz 45MHz 95MHz
Mod. Bit rate/
Bit Period
Time Slot
Period/Frame
Period
Modulation 0.3GMSK 0.3GMSK 0.3GMSK
MS Power 33dBm~13dBm 33dBm~5dBm 30dBm~0dBm
890~915
935~960
270.833kbps
3.692us
576.9us
4.615ms
EGSM 900
Phase 2
880~915
925~960
0~124 &
975~1023
270.833kbps
3.692us
576.9us
4.615ms
DCS1800
Phase 1
1710~1785
1805~1880
512~885
270.833kbps
3.692us
576.9us
4.615ms
Power Class 5pcl ~ 15pcl 5pcl ~ 19pcl 0pcl ~ 15pcl
Sensitivity -102dBm -102dBm -100dBm
TDMA Mux 8 8 8
Cell Radius 35Km 35Km 2Km
1-1
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SGH-C120 Specification
1-2. GSM TX power class
TX Power
control level
5 33±2dBm
6 31±2dBm
7 29±2dBm
8 27±2dBm
9 25±2dBm
10 23±2dBm
11 21±2dBm
GSM900
TX Power
control level
0 30±3dBm
1 28±3dBm
2 26±3dBm
3 24±3dBm
4 22±3dBm
5 20±3dBm
6 18±3dBm
DCS1800
12 19±2dBm
13 17±2dBm
14 15±2dBm
15 13±2dBm
16 11±3dBm
17 9± 3dBm
18 7±3dBm
19 5±3dBm
7 16±3dBm
8 14±3dBm
9 12±4dBm
10 10±4dBm
11 8±4dBm
12 6±4dBm
13 4±4dBm
14 2±5dBm
15 0±5dBm
1-2
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2. SGH-C120 Flow Chart of Troublesho oting
2-1.Baseband
2-1-1. Power ON
'Power On' does not work
Check the current consumption
Yes
Current consumption
>= 100mA
Yes
Check the Vbat Voltage
Voltage >=3.3V
Yes
Check the pin of U300
Pin#J12 >= 2.8V
Yes
Pin#A13 and
pin#A14 =2.8V
Yes
No
No
No
No
Download again
Charge the Battery
Check U300 and C315
pin#G11 =
1.8V
Yes
①
No
Check U300 and C316
②
Checktheclocksignalatpin#8ofU100
Freq = 13MHz
Vrms >=300mV
Vpp≒900mV
Yes
Check the initial operation
END
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③
No
Check the clock generation circuit
(related to OSC100)
2-1
④
SGH-C120 Flow Chart of Troubleshooting
③
④
①
②
②
①
2-2
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
SGH-C120 Flow Chart of Troubleshooting
F
T
L
X
A
_
S
T
R
R
R
R
T
T
T
T
X
X
X
X
_
_
_
Q
_
Q
I
I
N
N
P
P
PATUOA
NATUOA
PBTUOA
NBTUOA
PNICIM
NNICIM
PTUOCIM
NTUOCIM
PNIXUA
NNIXUA
PTUOXUA
NTUOXUA
C
3
2
2
K23KLC
CM_M31KLC
TNI_PSD
NO_GIJ
TSR
C
3
2
4
R
3
1
1
P
I
N
W
T
R
R
_
Q
K
E
E
P
NO_RWP
T
R
3
0
0
K
K
E
E
Y
Y
_
_
C
R
O
O
L
W
(
2
(
0
)
)
X
P
O
W
E
R
C
3
1
8
R
3
0
7
R
I
N
G
_
E
N
S
E
R
C
A
F
L
K
C
9D
CFA
7E
PXT
5B
2FERAR
6B
1FERAR
7D
PIXTXR
6D
NIXTXR
7C
PQXTXR
6C
NQXTXR
11P
PATUOA
21N
NATUOA
21R
PBTUOA
21P
NBTUOA
41N
PNICIM
41M
NNICIM
51N
PTUOCIM
51P
NTUOCIM
51M
PNIXUA
41L
NNIXUA
31K
31L
31R
MCVXV
31M
PGERV
41R
NGERV
4R
KCIAD
4P
NRIAD
6L
IDIAD
6M
ODIAD
4N
KLC_CTR
1D
QANEOX
6R
CM
5P
7CN
3P
RTNID
41C
51C
7L
9K
O_TESER
9M
01L
QRTNI
R
T
C
_
A
L
M
N
C
3
1
7
R
T
C
A
L
A
R
M
B
A
S
N
E
R
D
A
T
C
2
S
E
R
C
K
PTUOXUA
NTUOXUA
2WS_RWP
N1WS_RWP
FUB_1WSP
PEEK_RWP
C
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F
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1
0
X
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1
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V
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C
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3
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_
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B
(
0
:
1
5
)
D
D
D
D
D
D
S
S
S
S
S
S
P
P
P
P
P
P
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_
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D
D
D
D
D
B
B
B
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B
B
(
(
(
(
(
(
1
1
1
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1
1
4
5
3
2
0
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)
)
)
)
)
)
D
D
E
E
F
F
3
2
2
3
2
3
D
D
D
D
D
D
B
B
B
B
B
B
1
1
1
1
1
1
2
3
1
4
0
5
2
6CN
1
5CN
01K
71SDNG
01J
61SDNG
9J
51SDNG
8J
41SDNG
7J
31SDNG
9H
21SDNG
8H
11SDNG
7H
01SDNG
6H
9SDNG
01G
8SDNG
9G
7SDNG
8G
6SDNG
7G
5SDNG
01F
4SDNG
9F
3SDNG
8F
2SDNG
7F
1SDNG
4B
LTCO_DNG
4C
LTCO_DDV
31P
VDNG
11L
VDDV
6F
BDNG
6A
BDDV
01M
DDNG
11N
DDDV
6P
4SSV
2R
3SSV
4K
2SSV
5G
1SSV
4J
2OI_DDV
5N
1OI_DDV
6N
3DDV
3M
2DDV
3J
1DDV
11F
RUCH_
DNG
51K
2CSP_DNG
51B
1CSP_DNG
8E
QDNG
31B
76DDV
01C
S
S
I
I
M
M
S
I
_
_
M
C
R
_
L
S
I
O
K
T
K
K
J
1
1
1
1
1
4
V
R
T
C
_
2
.
9
V
5DDV
U
U
P
P
V
V
U
_
D
D
_
P
C
R
D
D
_
L
S
3
1
I
K
O
T
4
2
N
C
J
P
R
1
1
9
1
1
3
0
1
0
S
S
S
I
I
I
M
M
M
C
D
R
L
A
S
K
T
T
A
C
3
0
4
C
3
0
5
C
3
0
6
C
3
0
7
C
3
0
8
C
3
0
2
C
3
0
3
S
I
M
3
0
0
V
R
F
_
2
R
.
9
3
V
0
0
C
3
0
0
V
C
C
A
_
2
.
9
V
C
3
0
1
V
C
C
D
_
2
.
9
V
V
B
A
T
2-3
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SGH-C120 Flow Chart of Troubleshooting
RF_EN
C123
VRF_2.9V
VCCD_2.9V
C120
R104
13MHZ_BB
RTX_IP
RTX_IN
RTX_QP
RTX_QN
SERDAT
SERLE
SERCLK
XOENA
R105
R110
R106
R107
11
9
10
12
T
N
O
I
8
XOUT
7
BIP
6
BIN
5
BQP
4
BQN
3
SDIO
2
_SEN
1
SCLK
C
N
34
35
E
D
V
S
P
E
_
R
_
1
D
N
C
G
N
33
L
N
A
E
T
X
X
31
32
OSC100
3
2
30
U100
14
13
D
D
D
D
V
V
2
L
D
A
D
T
V
X
28
29
4
1
16
15
L
D
H
N
O
O
F
F
G
R
D
C
F
D
V
A
26
27
C134
R
RFIPP
RFIPN
RFIDP
RFIDN
RFIEP
RFIEN
RFIAP
RFIAN 24
E
D
V
I
O
D
M
X
X
25
C130
17
18
19
20
21
22
23
VRF_2.9V
R111
C133
AFC
2-4
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2-1-2. Initial
The pin #G11 of U101 =
the pin #J12 of U101 =
Initial Failure
Yes
1.8V and
2.8V ?
Yes
No
SGH-C120 Flow Chart of Troubleshooting
(if it has some problem, it is to be replaced.)
Check the U300
①
Is the pin #K9 of U101
"Low→High" ?
Yes
There is 32.768kHz wave
forms at the C216 and
C217
Yes
Is the pin #A4 of U300
is "High"
Yes
The voltage is "High" at
the C313,C315,C316
Yes
LCD display is O.K
No
No
No
No
No
(if it has some problem, it is to be replaced.)
Check the U300
Check the U200
Check the U100
Check the U300
Check the LCD part
②
③
④
①
Yes
No
Sound is O.K
Yes
END
Check the Audio part
2-5
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SGH-C120 Flow Chart of Troubleshooting
③
①
④
②
2-6
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KEY_ROW(0:4)
SGH-C120 Flow Chart of Troubleshooting
VCC_1.8A
VRTC_2.9V
VCCD_2.9V
C206
A(22)
R200
D(0:15)
A(0:20)
A(0)
A(1)
A(2)
A(3)
A(4)
A(5)
A(6)
A(7)
A(8)
A(9)
A(10)
A(21)
CP_CSROMEN
CP_CSRAMEN
DLC_DETECT
VCCD_2.9V
KEY_COL(0)
KEY_COL(1)
KEY_COL(2)
KEY_COL(3)
KEY_COL(4)
DEBUG_DTR
DEBUG_RTS
DEBUG_TXD
DEBUG_RXD
DEBUG_CTS
CHG_DET
SDS_TXD
SDS_RXD
SIMDATA
DEBUG_DCD
UPPER_BYTE
SIMCLK
LCD_CS
CP_WEN
CP_OEN
CHG_ON
BAT_CF
INTRQ
R206
LED_EN
R208
KEY_COL(0:4)
KEY_ROW(0)
KEY_ROW(1)
KEY_ROW(2)
KEY_ROW(3)
KEY_ROW(4)
A(11)
A(12)
A(13)
A(14)
R204
A(15)
A(16)
A(17)
A(18)
A(19)
A(20)
R205
R209
R210
R219
VCC_1.8A
0
6
5
4
7
3
1
1
1
1
L
N
1
2
L
H
2
D
C
C
N
2
5
D
N
N
A
S
V
_
C
5
_
3
3
A6
D(0)
D(1)
D(2)
D(3)
D(4)
D(5)
D(6)
D(7)
D(8)
D(9)
D(10)
D(11)
D(12)
D(13)
D(14)
D(15)
B13
F11
E14
D15
B15
C14
A16
A15
B17
C17
D16
F14
G14
G13
G17
J12
K12
K13
K14
L14
L15
L16
A12
A13
M15
M14
M11
N14
C13
P16
P15
T15
M9
XCP_D0
B5
XCP_D1
F8
XCP_D2
F7
XCP_D3
C5
XCP_D4
D6
XCP_D5
E7
XCP_D6
D5
XCP_D7
C4
XCP_D8
B4
XCP_D9
B3
XCP_D10
C1
XCP_D11
C2
XCP_D12
D2
XCP_D13
D3
XCP_D14
E3
XCP_D15
XCP_A0_BEON
XCP_A1
XCP_A2
XCP_A3
XCP_A4
XCP_A5
XCP_A6
XCP_A7
XCP_A8
XCP_A9
XCP_A10
XCP_A11
XCP_A12
XCP_A13
XCP_A14
XCP_A15
XCP_A16
XCP_A17
XCP_A18
XCP_A19
XCP_A20
XCP_A21
XCP_CSROMEN
XCP_CSRAMEN
XPA0/CS1N
XPA1/CS2N
XPA2/CS3N
XPA3/CS4N
XCP_WEN
XPA4/OEN
XPA5/WAITN
XPA6/BE1N
XPA7/IRQ1
T5
XPA8/IRQ2
P2
XPA9/IRQ3
N2
XPA10/IRQ4
A
2
P
A
X
_
6
3
A
P
X
1
0
2
3
N
N
N
N
I
I
I
I
S
S
S
S
/
/
/
/
1
0
2
3
B
B
B
B
K
K
K
K
_
_
_
_
P
P
P
P
C
C
C
C
X
X
X
X
2
5
4
4
1
L
L
T
R
M
1
0
1
7
1
9
1
7
6
6
9
8
1
1
L
K
J
L
L
K
M
L
S
S
S
S
S
S
S
N
0
S
S
S
S
S
S
S
S
V
V
V
V
V
V
V
C
_
2
3
A
P
X
5
2
1
7
3
6
7
C
A
A
H
J
H
G
G
F
A
S
S
S
S
S
S
S
S
S
D
S
S
S
S
S
S
S
S
S
D
V
V
V
V
V
V
V
V
V
V
U200
1
0
3
4
2
T
T
T
T
T
X
4
X
U
U
U
U
U
R
T
N
O
O
I
O
O
S
S
S
S
S
/
/
/
/
/
6
5
4
8
7
B
B
B
B
B
K
K
K
K
K
_
_
_
_
_
P
P
P
P
P
C
C
C
C
C
X
X
X
X
X
3
4
3
3
3
T
T
P
U
N
0
O
S
/
9
B
K
_
P
C
X
1
A
A
D
D
R
R
I
I
/
/
1
2
1
1
A
A
P
P
X
X
5
1
K
N
1
0
0
1
M
M
0
X
X
X
O
O
M
M
I
I
I
I
T
R
T
_
_
_
/
_
/
_
8
9
0
6
1
5
3
2
2
3
1
3
1
1
A
A
A
A
A
A
A
P
P
P
P
P
P
P
X
X
X
X
X
X
X
5
1
3
3
1
4
3
6
F
L
F
E
H
G
G
G
C207
VCC_1.8A
VCCD_2.9V
7
6
1
1
R
R
D
D
D
D
V
V
1
X
R
_
4
1
A
P
X
2
1
U
6
5
4
6
7
6
3
1
4
1
1
1
1
1
8
2
1
1
1
R
R
T
G
U
B
U
P
E
E
E
N
E
E
E
E
E
E
E
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
V
V
V
V
V
D
D
D
D
V
D
D
D
V
V
V
V
V
V
V
I
O
S
K
S
I
O
C
2
3
M
S
M
A
T
K
A
L
D
C
_
_
0
0
M
M
S
S
X
X
0
1
N
0
M
M
_
_
_
N
M
P
P
P
W
W
S
O
C
P
P
C
S
C
B
/
/
/
/
/
_
/
1
T
0
4
3
1
2
5
9
M
2
2
2
2
2
2
1
S
A
A
A
A
A
A
A
W
R
P
P
P
P
P
F
P
P
P
X
X
X
X
X
X
X
X
X
6
1
5
5
3
4
4
6
2
J
L
F
L
H
H
R
K
M
0
2
2
R
C205
C208
VREF
CLK13M_TR
TR_RST
6
1
2
5
0
0
7
1
1
2
1
1
8
1
1
1
1
1
U
M
B
F
F
C
G
D
E
E
C
I
F
L
L
E
E
E
A
C
A
B
K
L
L
E
T
D
D
V
1
M
O
_
6
2
A
P
X
2
G
T
D
D
S
D
C
P
P
R
S
R
S
D
D
D
D
D
V
V
V
R
V
V
V
_
_
X
S
D
S
D
V
V
F12
TDO
F15
TRST
H12
TDI
G12
TMS
H13
TCK
G15
CKO
L12
IOBIT#2
K11
IOBIT#1
N4
INT#0
R12
IO7
U5
RWN
T17
DSP_AB(8)
AB#8
T14
DSP_AB(7)
AB#7
R14
DSP_AB(6)
AB#6
P12
DSP_AB(5)
AB#5
P11
DSP_AB(4)
AB#4
N11
DSP_AB(3)
AB#3
R13
DSP_AB(2)
AB#2
M10
DSP_AB(1)
AB#1
U13
DSP_AB(0)
AB#0
P10
DSP_DB(15)
DB#15
R11
DSP_DB(14)
DB#14
T11
DSP_DB(13)
DB#13
U11
DSP_DB(12)
DB#12
M8
DSP_DB(11)
DB#11
N8
DSP_DB(10)
DB#10
N7
DSP_DB(9)
DB#9
P7
DSP_DB(8)
DB#8
M6
DSP_DB(7)
DB#7
R7
DSP_DB(6)
DB#6
T7
DSP_DB(5)
DB#5
U7
DSP_DB(4)
DB#4
P6
DSP_DB(3)
DB#3
R6
DSP_DB(2)
DB#2
U6
DSP_DB(1)
DB#1
P5
DSP_DB(0)
DB#0
D12
XTIC_MODE
M12
XCPTSTSTOP_CKO
D11
XAG3
E11
XAG2
A11
XAG1
B11
XAG0
B7
XBSWN
A7
K
L
C
_
1
M
S
_
7
2
A
P
X
4
G
X1RTC
D10
B
A
X2RTC
K
Q
Q
0
C
Q
A
R
_
D
T
_
_
8
7
1
1
A
A
P
P
X
X
4
3
1
E
P
E8
E
E
XRTCALARM_N
N
R
R
C6
T
_
_
S
XOSC32OUT
I
S
O
K
T
T
M
D
R
D
C
_
_
T
T
T
T
4
3
T
_
_
_
_
3
3
_
P
P
P
P
P
A
A
C
C
C
C
P
P
C
X
X
X
X
X
X
X
8
9
7
7
7
7
3
1
1
1
F
C
D
G
D
N
M
C221C220
C219
ICHRG
TR_RST
RTCALARM
CLK32K
C222
DEBUG_DSR
EAR_SWITCH
VIB_EN
JACK_IN
PWR_KEEP
SIMRST
DEBUG_RI
FLASH_RESET
LED_EN
RING_EN
UP_CS
UP_SCLK
UP_SDO
UP_SDI
CP_TDO
TR_RST
CP_TDI
CP_TMS
CP_TCK
DSP_TDO
TR_RST
DSP_TDI
DSP_TMS
DSP_TCK
DSP_INT
DSP_IO
DSP_RWN
DSP_AB(8:0)
DSP_DB(15:0)
R213
100K
41
C216
C217
23
OSC200
VCCB_2.9V
R202
TH200
R203
C215
VBAT
R212
C218
R214
2-7
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
SGH-C120 Flow Chart of Troubleshooting
2-1-3. Sim Part
"Insert SIM is displayed on the LCD
Yes
Check the SIM
connector's (SIM300)
connection to SIM card
Yes
Check the voltage at
pin#1 of SIM300 >=
2.8V ?
Yes
Is there any signals
pin#2,#3,#4 of SIM300 ?
Yes
Check the SIM Card
END
No
No
No
Resolder or change SIM300
Check the U300
Check the U200 & U300
①
②
③
2-8
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
SGH-C120 Flow Chart of Troubleshooting
③
②
①
③
2-9
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
SGH-C120 Flow Chart of Troubleshooting
2-1-4. Microphone Part
Microphone does not work
Yes
Is the assembled status
of microphone O.K?
Yes
Check the reference voltage on mic path
Yes
VR401≒2.0V ?
Yes
Is microphone ok?
Yes
END
No
No
No
Reassembled the microphone
Resolder or change
R400,R401,R402,R403,R404,R405
R407,R410,R413,R414,L400,L401
C403,C407,C413
Check U300
①
②
2-10
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
SGH-C120 Flow Chart of Troubleshooting
①
②
2-11
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
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