1. Service Manual
Model :GD638/C705

2. Content Specification Method of SW Download Circuit Description
* Phone layout * Icons Status of SLT100 LCD * H/W Features * S/W Features
Specification
Method of SW Download
* Baseband Section * RF Section
Circuit Description
* Main Board * Trouble Shooting
Trouble Shooting
TEST Mode

3. Specification

4. Specification Icons Status of LCD -1 Icon Description
Signal Strength : Shows the strength of the receiving signal. The greater the number of bars,
The better the signal strength
Roaming : Appears when the phone is roaming
L1,L2 : Some SIM cards support two phone numbers and you can switch the number with this feature. The phone will display this icon when you set a line
Missed Calls : Appears when there is missed call (s)
New Message : Appears when a new incoming text message is arrived and unread
MMS Unread : Appears when a new MMS message is arrived and unread
MMS Busy : Appears when MMS is busy, such as receiving and sending a message
Broadcast Message : Appears when Broadcast Message receive mode is active
Call Barring On : Appears when the call barring mode is active

5. Specification Icons Status of LCD-2 Icon Description
Call Forward : Appears when the call forward mode is active.
IrDA : Appears when the IrDA port is activated.
Ring : Appears when the Ring mode is active.
Vibrate and Ring : Appears when the Vibrate and Ring mode is active.
Vibrate then Ring : Appears when the Vibrate then Ring mode is active.
Vibrator On : Appears when the Vibration mode is active.
Silent Mode : Appears when the silent mode (manner mode) is active
Alarm On : Appears when you set the alarm.
Stopwatch : Appears when you set the stopwatch.
Lock : Appears when you set the phone lock.
Battery Strength : Shows the level of your battery. The more bars you see, the more power you have left
General : Appears when you set the sound & Light profile as General.
Meeting : Appears when you set the sound & Light profile as Meeting.

6. Specification Icons Status of LCD -3 Icon Description
Outdoor : Appears when you set the Sound & Light profile as Outdoor.
Indoor : Appears when you set the Sound & Light profile as Indoor.
Headset : Appears when you set the Sound & Light profile as Headset.

7. Specification H/W Features Feature Description Dimension Main LCD
96(L) x 49(W) x 14.9(D) mm
Main LCD
2.0” 262k TFT LCD (176x220)
Sub LCD
N/A
Camera
0.3 Mega CMOS
Flash Light
Yes
Speaker
Stereo (Dual Speaker)
Vibrator
Built – in vibrator
Antenna
Internal
SIM 3V
BlueTooth
Yes (hands free (HSP,HFP)) Stereo (GAVDA,A2DP,AVRCP)
Data Transfer (FTP, OPP)
FM Radio
Recode Format : WAR,AMR
Data
USB Connection and PC Link Manager
microSD
(T-Flash Card)
%Use only genuine microSD(T-Flash) cards approved & specified by the SD card Association and SanDisk

8. Specification S/W Features Feature Description RF Message Text Input
GSM900 ,DCS1800 ,
Message
MMS
Text Input
T9 Intelligent Text Input
Camera
0.3Mega CMOS Camera
Video
Video Record & Play ( MJpeg)
Wallpaper
Pictures and user definable JPG, GIF, BMP
Sound
64 Polyphonic True Sound MIDI, iMelody, WAV, MP3
Phonebook
500 of Phonebook
Tools
Calendar,, Alarm, Calculator,

9. Circuit Description (Baseband Section)
1.SC6610 (GSM/GPRS Base band Processor)
Baseband POWER PART
Baseband ANALOG PART
Baseband DIGITAL PART

10. Circuit Description (Baseband Section)
1. Micro-Controller Unit Subsystem
- Processor Core
- Memoru Management
- Bus System
- Direct Memory Acess
- Interrupt Controller
- Internal Memory Controller
- External Memory Interface
Block Diagram of SC6620

11. Circuit Description (Baseband Section)
2. Micro-Controller Peripherals
- Pulse-Width Modulation Outputs
- Alerter
- SIM Interface
- Keypad Scanner
- General Purpose Inputs/Outputs
- UART
- Real Time Clock
- Auxiliary ADC Unit
- IrDA framer
SIM Interface Block Diagram
3. Micro-Controller Coprocessors
4. Multi-Media Subsystem
Camera Interface
Image Scaler
LCD Interface
Video&Image codec subsystem
LCM Interface Block Diagram

12. Circuit Description (Baseband Section)
5. Audio Front-End
Audio Block Diagram

13. Circuit Description (Baseband Section)
6. Radio Interface Control
Baseband Serial Interface
Baseband Parallel Interface
Automatic Power Control (APC)
Unit
Automatic Frequenncy Control
(AFC) Unit
Block Diagram of APC unit
Block Diagram of the AFC Controller

14. Circuit Description (Baseband Section)
7. Baseband Front End
Baseband Serial Ports
Downlink Path (RX Path)
Uplink Path (TX Path)
8. Timing Gemerator
9. Power, Clocks Reset
Baseband to PMIC Serial Interface
Clocks
Reset Management
Block Diagram of Downlink Path
Block Diagram of Uplink Path

15. Circuit Description (RF Section)
1. SR528 (RF Transceiver IC)
INPUT
26M RX
OUTPUT26M TX
PMIC ( Power management IC)

16. Circuit Description (RF Section)
1. Receiver
2. Transmitter
3. TX VCO
4. Frequency Synthesizer
5. Voltage Control Crystal Oscillator
(13MHz or 26MHz)
6. Regulator
SR528 Functional Block Diagram

17. Circuit Description (RF Section)
2. RDA6231 (EGSM, DCS Power Amplifier Module)
RX INPUT
TX OUTPUT
PAM IC ( Power Amplifier Module IC)

18. Circuit Description (RF Section)
RDA6231 Block Diagram

19. Main Bord
TOP Surface Component

20. Main Bord
Bottom Surface Component

21. PCB LAYOUT (TOP – Reference)

22. PCB LAYOUT (Bottom – Reference)

23. Trouble Shooting 1. Power on Repair chart
TOP Side
1. Check VBAT(3.8V) .If not ,Check the C810
VSIM 1.8V/3.0V – C208,C207
VMEM 2.8V- C500
VRTC 1.5V – C210
VCORE 1.8V- C220
U201
3. Check the Input X-Tal Khz . (X201)
If not ,Check the X201 Defective or Cold solder
4. Check the Output TCXO 26MHz (X400)
If not ,Check the X400 Defective or Cold solder
5. Re download
If not . Change CPU (U100) or MEMORY (U500)
U500

24. Trouble Shooting 2. LCD Dead Repair chart (1)
1. Check the Connector ,LCD FPCB,LCD-Connector
If not , Change the F-PCB,LCD
2. Check R606
Defective or Cold solder
If not, Check the CPU Defective or Cold solder
CON10
U500
U100

25. Trouble Shooting 3. LCD Dead Repair chart – Touch Pannel (2)
1,Check the LCD FPCB MODULE
If not Change the LCD FPCB CONNECTOR
2, Check the R601,R602,R603,R604and TVS T601,
T602,T603,T604
If not ,Change the Resistance and TVS
U700
U500
LCD CONNECTOR

26. Trouble Shooting 4. SIM Error Repair chart
1. After insert SIM ,Check the LCD Display.
2. Check the voltage out. SIMCARD. 4,2 PIN
(1.8V/3.0V)
If not ,Check the CPUDefective or Cold solder.
SIMCARD
U300

27. Trouble Shooting 5. Melody Dead Repair chart AUDIO PA CLASS K
1. Check the speaker Spring state on Rear Cover
If not good, Change the Speaker
2. Check the audio pa U302IS OK
If not , Change the U302
CON130
AUDIO PA CLASS K

28. Trouble Shooting 7. Audio Dead Repair chart - (2)
1. Check the MIC. MIC1
If not ,Check the MIC1 Defective or Cold solder.
2. Check the MICBIASP of voltage is ok
If not ,Check the CPUDefective or Cold solder
MIC

29. Trouble Shooting 7. Audio RECEIVER Repair chart RECEIVER
1. Check the RECP. RECN
If not ,Check the REC Defective or Cold solder.

30. Trouble Shooting 8. Vibrator Dead Repair chart VIB
1. Check the LCD,FPCB
If not , Change the LCD,FPCB
2. Check the voltage of D801
If not , Change the Vibrator

31. Trouble Shooting 9. Camera Dead Repair chart U300
1. Check the connector state or camera module.
If not ,Change the camera module
3. Check the voltage. 2 PIN (1.8V) 19 PIN (2.8V)
If not ,Check the CPU Defective or Cold solder
Camera Connector

32. Trouble Shooting 10. T-Flash Card Dead Repair chart
1 Check the T-Flash
If not Good, Change the T-Flash.
2. Check the voltage of VDDSD is ok
If not ,Check the CPU Defective or Cold solder
U300
T-FLASH

33. Trouble Shooting 12. Charger Dead Repair chart MOS P-FET
1. Check the MOS P-FET Defective or Cold solder
If not ,Change the MOS P-FET.
MOS P-FET

34. Trouble Shooting 13. FM+BT Receiver Dead Repair chart
1. Check the Ear-Mic phone state
If not ,Change the Ear-MIC phone.
2,Check the Voltage 6 PIN(3.0V)
If not, Change the U100
BT+FM

35. Deberg Code Aoto ModeTest : *#888*# Code Test Infomation 1 Mmi Ui-Test2
Version Info 3
Adc Calibrate info 4
Battery 5
Key Pad Test 6
LCD Test 7
Rtc Test 8
Vibrate Test 9
Backlight Test 10
Loopback Test 11
Torch Light Test 12
Bluetooth Test 13
Headset Test 14
Melody Test 15
MemorCard Test 16
FM radio Test

36. Deberg Code Test Mode Code Test Information *#1# SW Version Check
*#06#
IMEI Number