Samsung SGH-D428 User manual

GSM TELEPHONE
SGH-D428
GSM TELEPHONE CONTENTS
1. Specification
2. Flow Chart of Troubleshooting
3. Exploded Views and Parts List
4. Electrical Parts List
5. Block Diagrams
6. PCB Diagrams

Samsung Electronics Co.,Ltd. Dec. 2004
Printed in Korea.
Code No.: GH68-06337A
BASIC.
ⓒ
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.

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1. SGH-D428 Specification
This Document can not be used without Samsung's authorization
1-1
GSM900
Phase 1
EGSM 900
Phase 2
DCS1800
Phase 1 PCS1900
Freq. Band[MHz]
Uplink/Downlink
890~915
935~960
880~915
925~960
1710~1785
1805~1880
1850~1910
1930~1990
ARFCN range 1~124 0~124 &
975~1023 512~885 512~810
Tx/Rx spacing 45MHz 45MHz 95MHz 80MHz
Mod. Bit rate/
Bit Period
270.833kbps
3.692us
270.833kbps
3.692us
270.833kbps
3.692us
270.833kbps
3.692us
Time Slot
Period/Frame
Period
576.9us
4.615ms
576.9us
4.615ms
576.9us
4.615ms
576.9us
4.615ms
Modulation 0.3GMSK 0.3GMSK 0.3GMSK 0.3GMSK
MS Power 33dBm~13dBm 33dBm~5dBm 30dBm~0dBm 30dBm~0dBm
Power Class 5pcl ~ 15pcl 5pcl ~ 19pcl 0pcl ~ 15pcl 0pcl ~ 15pcl
Sensitivity -102dBm -102dBm -100dBm -100dBm
TDMA Mux 8 8 8 8
Cell Radius 35Km 35Km 2Km -
1. GSM General Specification

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SGH-D428 Specification
1-2
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2. GSM TX power class
TX Power
control level GSM900
533±2dBm
631±2dBm
729±2dBm
827±2dBm
925±2dBm
10 23±2dBm
11 21±2dBm
12 19±2dBm
13 17±2dBm
14 15±2dBm
15 13±2dBm
16 11±2dBm
17 9±2dBm
18 7±2dBm
19 5±2dBm
TX Power
control level DCS1800
030±3dBm
128±3dBm
226±3dBm
324±3dBm
422±3dBm
520±3dBm
618±3dBm
716±3dBm
814±3dBm
912±4dBm
10 10±4dBm
11 8±4dBm
12 6±4dBm
13 4±4dBm
14 2±5dBm
15 0±5dBm
TX Power
control level PCS1900
030±3dBm
128±3dBm
226±3dBm
324±3dBm
422±3dBm
520±3dBm
618±3dBm
716±3dBm
814±3dBm
912±4dBm
10 10±4dBm
11 8±4dBm
12 6±4dBm
13 4±4dBm
14 2±5dBm
15 0±5dBm

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2. SGH-D428 Flow Chart of Troubleshooting
2-1
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1.Baseband
1. Power ON
Check the current
consumption more
than 100mA
'Power On' does not work
Check the VBAT
more than 3.3V
Download again
Charge the Battery
Check the pin
11 of U102 is
more than 2.8V
Check the C117
U102 pin 33,39
=2.8V Check U102 and C116
Check the clock
signal at pin4 of
OSC801
Freq=13MHz ?
Vrms≥300mV ?
Vpp is around
900mVpp ?
Check the clock generation
circuit
Check the initial operation
END
No
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
U102 pin 9
=1.8V
No
Yes

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SGH-D428 Flow Chart of Troubleshooting and Circuit Diagrams
2-2
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2. Initial
3. Sim Part
Check the signal at the
pin 21 of U102 is
"High" when the phone
is boot on
Initial Failure
Check the pin 46,20 and Q103
END
No
Yes
Checkthekeymetrix
of the U601
Yes
Check the key program and
the key pcb
Check the VCCD,VCC_1.8A
of U601
Check the soldered status of U601,
OSC601
Yes
No
No
Yes
Yes
Check LCD connector CN201 in the main
PBA and the FPCB connector
Yes
Check the vccd of
U601 is around 2.8V
Check the soldered status of
U601,osc601
No
Check the pin 1 of
CN101. voltage 3V ?
Phone can't access SIM card
Check the SIM
connector's (CN101)
connection to SIM
card
Check the circuit related to
U102
Resolder or change CN101
Check the circuit around CN101
input
circuitry
END
No
Yes
Yes
Yes
Yes
No
Check the related circuit of
CN101
No
Check the circuit around U601
output
and vlotage supply circuitry
Yes
Check the related circuit of
U601 and U102
No

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SGH-D428 Flow Chart of Troubleshooting and Circuit Diagrams
2-3
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4. Charging Part
Check the pin 17, 18
of CN300 is
TA_VEXT>4?
Abnormal charging part
Check the pin 2 of
U101 is "low"?
Replace TA,Check CN300-1
Check the U101
Check the Q101
END
No
Yes
Yes
Yes
Yes
No
No
Check the pin 3 of
Q101 is "low"?
Check the pin 5 of
U101 is "3.2~4.2V"? Check the U101
No
Yes
Check the ICHRG is
1V(during charging)
and around
180mV(full charging)?
No Resolder or change R111
Yes

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SGH-D428 Flow Chart of Troubleshooting and Circuit Diagrams
2-4
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5. Microphone Part
6. Speaker Part
check the soldered
status of microphone.
Microphone does not work
Check the reference
voltage on mic path
C411 ≒2.5 V
Resolder microphone
Resolder or change
R413,C420,R414,C410,R411,R40
8
END
No
Yes
Yes
Yes
Yes
No
Is microphone ok? No
Check U701
Check the FPCB from
CN201 to CN11
Speaker does not work
Check the PIN 4 of
U401='High' ?
Retry connection the FPCB from
CN201 to CN11
Check U401 and the audio
path of U701
Is speaker ok?
Check componants near the U402
and control line of U402
END
No
Yes
Yes
Yes
Yes
No
No
Is speaker ok?
Change Speaker
Yes
No

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SGH-D428 Flow Chart of Troubleshooting and Circuit Diagrams
2-5
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F1001 CHECK
pin13 ≥-65dBm ?
2.RF
1. EGSM RX
CONTINUOUS RX ON
RF INPUT : 62CH
AMP : -50dBm
NORMAL CONDITION
catch the channel?
CHECK
ANT1001,L1002 contact ?
U902
pin 26,32: 2.8V ?
F1001 CHECK
pin1, 2 ≥-65dBm ?
U1002 CHECK
pin20,21 ≥-65dBm ?
C1003, C1006
resolder or change
F1001
resolder or change
C1005,C1006,L1003
resolder or change
U102 pin39, C112
change or resolder
U903 CHECK
pin 7 : 13MHz ?
Vp-p : 950mV?
OSC801
change or resolder
U902
resolder or change
U702,R701
resolder or change
U902
pin1,2,5,6 Vp-p
:120mV?
NO
YES
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES

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SGH-D428 Flow Chart of Troubleshooting and Circuit Diagrams
2-6
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F1001 CHECK
pin13 ≥-65dBm ?
2. DCS RX
CONTINUOUS RX ON
RF INPUT : 698CH
AMP : -50dBm
NORMAL CONDITION
catch the channel?
CHECK
ANT1001,L1002 contact ?
U902
pin 26,32: 2.8V ?
F1001 CHECK
pin3, 4 ≥-65dBm ?
U902 CHECK
pin21,22 ≥-65dBm ?
C1008,C1009
resolder or change
F1001
resolder or change
C1008,C1009,L1004
resolder or change
U102 pin39, C112
change or resolder
U903 CHECK
pin 7 : 13MHz ?
Vp-p : 950mV?
OSC801
change or resolder
U902
resolder or change
U703,R704
resolder or change
U902
pin1,2,5,6 Vp-p
:120mV?
NO
YES
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES