Samsung SGH-P738 User manual

GSM TELEPHONE
SGH-P738
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

Samsung Electronics Co.,Ltd. Nov. 2004
Printed in South Korea.
Code No.: GH68-06167A
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.

1. SGH-P738 Specification
1-1
1. GSM General Specification
GSM900
Phase 1 EGSM 900 Phase 2 DCS 1800 Phase 1
Freq. Band [MHz]
Uplink/Downlink 890~915 935~960 880~915 925~960 1710~1785 1805~1880
ARFCN range 1~124 0~124 & 975~1023 512~885
Tx/Rx spacing 45MHz 45MHz 95MHz
Mod. Bit rate /
Bit Period 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
Modulation 0.3GMSK 0.3GMSK 0.3GMSK
MS Power 33dBm~13dBm 33dBm~5dBm 30dBm~0dBm
Power Class 5pcl ~ 15pcl 5pcl ~ 19pcl 0pcl ~ 15pcl
Sensitivity -102dBm -102dBm -100dBm
TDMA Mux 8 8 8
Cell Radius 35Km 35Km 2Km

SGH-P738 Speclflcation
1-2
2. GSM Tx Power Class
Tx Power
control level GSM900
533±3dBm
631±3dBm
729±3dBm
827±3dBm
925±3dBm
10 23±3dBm
11 21±3dBm
12 19±3dBm
13 17±3dBm
14 15±3dBm
15 13±3dBm
16 11±3dBm
17 9±3dBm
18 7±3dBm
19 5±3dBm
Tx Power
control level
DCS1800
030±3 dBm
128±3 dBm
226±3 dBm
324±3 dBm
422±3 dBm
520±3 dBm
618±3 dBm
716±3 dBm
814±3 dBm
912±4 dBm
10 10±4 dBm
11 8±4 dBm
12 6±4 dBm
13 4±4 dBm
14 2±5 dBm
15 0±5 dBm

2. SGH-P738 Flow Chart of Troubleshooting and Circuit Diagrams
2-1
1. Power On
check the current
consumption more
than 100mA Download again
'Power ON' does not work
No
Yes
Yes
END
Yes
Check the Initial Operation
Check U101 and C116
Yes
Yes
Check U101
pin 39 =
2.8V
No No
Yes
Charge the battery
No
Check the Voltage
of the Battery more
than 3.5V
check keypad
No
Check the pin11 of
U101 is more than
2.8V
Check
"Power On"
key?
No
check U101 and C117
Yes
U101 pin9
=1.8V

SGH-P738 Flow Chart of Troubleshooting and Circuit Diagrams
2-2
2. Initial
END
Yes
Check the signal at
the pin 21 of U101 is
"High" when the phone
is boot on
Initial Failure
Check pin4 of OSC402
Voltage is 2.8V ?
Check U401
Check pull_up R603,pin39 of U101,
OSC600, C613
No
Yes
Yes
No
No
Check pin5 of U103
Voltage is 2.5V?
Check or Change U300
Yes
Yes
No
Check pin3 of OSC600,
Frequency is 13MHz? Check or change OSC600
Check OSC300 is
working? No
Check the soldered status of U103,
U401

SGH-P738 Flow Chart of Troubleshooting and Circuit Diagrams
2-3
3. Sim Part
*TestwithSim
Check the pin 1 of
CN104. voltage 3V?
Phone can't access SIM card
Check the SIM
connector's (CN104)
connection to SIM
card
Check the circuit related to U101
Resolder or change CN104
END
No
Yes
Yes
Yes
No
Check the circuit
around CN104 input
circuitry Check the related circuit of CN104
Yes
No
Check the circuit
around U401 output
and voltage supply
circuitty
Check the related circuit of U401 and
U101
Yes
No

SGH-P738 Flow Chart of Troubleshooting and Circuit Diagrams
2-4
4.Microphone Part
* Call with Sim before testing.
Check the soldered
status of microphone
MicroPhone does not work
Resolder microphone
END
No
Yes
Yes
Check the reference
voltage on mic path
C201 ≒2.0V
Yes
Resolder or change
R203, C209, R204, R201, R200,
C200
No
Is microphone OK?
Yes
Check U501
No

SGH-P738 Flow Chart of Troubleshooting and Circuit Diagrams
2-5
5.Directional MIC Part
Directional MIC does not work
*When you play MPEG file, if Audio is not active
Check MIC "+" terminal,
Bias Voltage = 2.6V?
Yes
Resolder R249
No
Check pin21 of U200,
Voltage = 1.76V?
Yes
Resolder C244
No
Change directional MIC
Yes

SGH-P738 Flow Chart of Troubleshooting and Circuit Diagrams
2-6
6. Speaker Part
*Callbeforetesting.
Check the soldered
status of Speaker
Receiver does not work
Check the pin 7 of U202
"High"?
Resolder Speaker
Check U202 and the audio path of
U501
END
No
Yes
Yes
No
Is Speaker working?
Is Speaker working ?
Check the path from U501 to CN304
Change Speaker
No
Yes
Yes
No