LG Vodafone GM750 User manual

Service Manual Model : GM750
Internal Use Only
Service Manual
GM750
Date: September, 2009 / Issue 1.0

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Table Of Contents
1. INTRODUCTION...............................................5
1.1 Purpose......................................................................5
1.2 Regulatory Information.................................................5
2. PERFORMANCE............................................... 7
2.1 Product Name .............................................................7
2.2 Supporting Standard....................................................7
2.3 Main Parts : GSM Solution ...........................................7
2.4 HW Features ..............................................................8
2.5 SW Features .............................................................10
2.6 HW SPEC..................................................................22
3. TECHNICAL BRIEF......................................... 29
3.1 GENERAL DESCRIPTION.............................................29
3.2 GSM MODE...............................................................31
3.3 UMTS MODE.............................................................35
3.4 GPS MODE ...............................................................38
3.5 LO GENERATION and DISTRIBUTION CIRCUIT ..............39
3.6 OFF-CHIP RF COMPONENTS......................................40
3.7 Digital Baseband(DBB/MSM7200A) ............................44
3.2 Hardware Architecture ...............................................45
3.9 Subsystem(MSM7200A) ............................................47
3.10 Power Block............................................................50
3.11 External memory interface .......................................55
3.12 H/W Sub System .....................................................57
3.13 Audio and sound .....................................................66
3.14 Camera interface.....................................................73
3.15 Proximity Sensor .....................................................80
3.16 Luminance Sensor...................................................81
3.17 Motion Sensor.........................................................82
3.18 Main Features.........................................................83
4. TROUBLE SHOOTING..................................... 88
4.1 RF Component ..........................................................88
4.2 SIGNAL PATH ............................................................91
4.3 Checking TCXO Block ................................................94
4.4 Checking Front End Module (FEM) Block.....................96
4.5 Checking WCDMA Block ............................................99
4.6 Checking GSM Block ...............................................111
4.7 Power ON Troubleshooting .......................................117
4.8 Charger Troubleshooting ..........................................119
4.9 USB trouble.............................................................122
4.10. Audio trouble........................................................124
4.11 5M Camera trouble ...............................................137
4. 12 VGA Camera trouble .............................................140
4.13 Main LCD trouble ..................................................144
4.14 SIM Detect Troubleshooting....................................146
4.15 Keypad Backlight Troubleshooting...........................148
4.16 LINEAR MOTOR.....................................................149
4.17 Proximity Sensor on/off trouble...............................150
4.18 Luminance Sensor on/off trouble............................152
4.19 Motion Sensor on/off trouble ..................................154
5. Download ................................................... 156
6. Block Diagram ........................................... 172
7. CIRCUIT DIAGRAM...................................... 185
8. BGA Pin Map ..............................................195
9. PCB LAYOUT ............................................... 203
10. Calibration................................................ 211
10.1. Calibration & RF Auto Test Program (Tachyon).........211
10.2 How to use Tachyon...............................................214
11. Test Mode.................................................217
12. EXPLODED VIEW & REPLACEMENT
PART LIST ................................................227
12.1 EXPLODED VIEW .....................................................27
12.2 Replacement Parts ................................................229
12.3 Accessory .............................................................257

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
1. INTRODUCTION

1.1. Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of this model.
1.2. Regulatory Information
A. Security
Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company’s employees, agents, subcontractors, or person working on your
company’s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system.
There are may be risks of toll fraud associated with your telecommunications system. System users
are responsible for programming and configuring the equipment to prevent unauthorized use. The
manufacturer does not warrant that this product is immune from the above case but will prevent
unauthorized use of common carrier telecommunication service of facilities accessed through or
connected to it. The manufacturer will not be responsible for any charges that result from such
unauthorized use.
B. Incidence of Harm
If a telephone company determines that the equipment provided to customer is faulty and possibly
causing harm or interruption in service to the telephone network, it should disconnect telephone
service until repair can be done. A telephone company may temporarily disconnect service as long as
repair is not done.
C. Changes in Service
A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the phones or compatibility with the net
work, the telephone company is required to give advanced written notice to the user, allowing the user
to take appropriate steps to maintain telephone service.
D. Maintenance Limitations
Maintenance limitations on the phones must be performed only by the manufacturer or its authorized
agent. The user may not make any changes and/or repairs expect as specifically noted in this manual.
Therefore, note that unauthorized alternations or repair may affect the regulatory status of the system
and may void any remaining warranty.
E. Notice of Radiated Emissions
This model complies with rules regarding radiation and radio frequency emission as defined by local
regulatory agencies. In accordance with these agencies, you may be required to provide information
such as the following to the end user.

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION


F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.
G. Interference and Attenuation
A phone may interfere with sensitive laboratory equipment, medical equipment, etc. Interference from
unsuppressed engines or electric motors may cause problems.
H. Electrostatic Sensitive Devices
ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated by the sign. Following
information is ESD handling:
• Service personnel should ground themselves by using a wrist strap when exchange system boards.
• When repairs are made to a system board, they should spread the floor with anti-static mat which is
also grounded.
• Use a suitable, grounded soldering iron.
• Keep sensitive parts in these protective packages until these are used.
• When returning system boards or parts like EEPROM to the factory, use the protective package as
described.


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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
2. PERFORMANCE
2.1 Product Name
GM750 : WCDMA900/1900/2100+EGSM/GSM850/DCS/PCS
(HSDPA 7.2Mbps / GPRS Class 12 / EDGE Class 12)
2.2 Supporting Standard
Item Feature Comment
Supporting
Standard
WCDMA(FDD1,2,8)/EGSM/GSM850/DCS1800/P
CS1900 with seamless handover
Phase 2+(include AMR)
Frequency Range WCDMA(FDD1) TX : 1920 – 1980 MHz
WCDMA(FDD1) RX : 2110 – 2170 MHz
WCDMA(FDD2) TX : 1850 – 1910 MHz
WCDMA(FDD2) RX : 1930 – 1990 MHz
WCDMA(FDD8) TX : 880 – 915 MHz
WCDMA(FDD8) RX : 925 – 960 MHz
EGSM TX : 880 – 915 MHz
EGSM RX : 925 – 960 MHz
GSM850 TX : 824 – 849 MHz
GSM850 RX : 869 – 894 MHz
DCS1800 TX : 1710 – 1785 MHz
DCS1800 RX : 1805 – 1880 MHz
PCS1900 TX : 1850 – 1910 MHz
PCS1900 RX : 1930 – 1990 MHz
Application
Standard
WAP 2.0, JAVA 2.1
2.3 Main Parts : GSM Solution
Item Part Name Comment
Digital Baseband MSM7200A : Qualcomm
Analog Baseband PM7540 : Qualcomm
RF Chip RTR6285 : Qualcomm

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
2.4 HW Features
Item Feature Comment
Form Factor Bar type
1) Capacity
Standard : Li-Poly, 1500mAh
Battery
2) Packing Type : Soft Pack
Size Standard :
109.8 x 53.5 x 12.9mm
Weight 119g With Battery
Stand by time 2G Up to 600 hrs
3G Up to 500 hrs
@ Paging Period 5 (2G)
@ DRX 7 (3G)
Charging time Within 3 hrs @ Power Off / 1500mAh
Talk time 2G Up to 5 hrs
3G Up to 6.4 hrs
@ Power Level 5 (2G)
@ Tx = 12dBm (3G)
RX sensitivity WCDMA(FDD1) : -108 dBm
WCDMA(FDD2) : -107.5 dBm
WCDMA(FDD8) : -108 dBm
EGSM : -107 dBm
GSM850 : -107 dBm
DCS 1800 : -107 dBm
PCS 1900 : -107 dBm
TX output power WCDMA/
GSM/
GPRS
WCDMA :
22.5dBm/3.84MHz,+1/-
3dBm
EGSM : 32.5dBm
GSM850 : 32.5 dBm
DCS1800 : 29.5 dBm
PCS 1900: 29.5 dBm
EDGE compatibility GPRS Class 12
EDGE
Class 12
Class3(WCDMA)
Class4 (EGSM)
Class4 (GSM850)
Class1 (PCS)
Class1 (DCS)
SIM card
type
Plug-In
SIM
3V /1.8V
E2 (GSM900)
E2 (PCS)
E2 (DCS)
Display Main LCD
TFT Main LCD(3 inch, 240 x 400)
Built-in Camera 5M CMOS Camera
CMOS Camera (VGA)
Status Indicator Yes
Keypad Touch Screen
Navigation Key : Optical Joystick
Side Key : 5
Side Key : Power&Lock,
Volume up/down
Multitasking, Camera
ANT Main : Internal Fixed Type
System connector 5 Pin u-USB
Ear Phone Jack 12x18 Oval Type (Speaker/Receiver
dual mode)

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
PC synchronization Yes
Memory NAND Flash : 4Gb
SDRAM : 2Gb
Speech coding FR, EFR, HR,AMR
Vibrator Built in Vibrator
Blue Tooth Bluetooth 2.1+EDR
MIDI(for Buzzer
Function)
SW Decoded 72Poly
Music Player MP3/ WMA/AAC/HE-AAC/EAAC+
Video Player MPEG4, H.263, WMV9
Camcorder MPEG4, H.263,
Voice Recording Yes
Speaker Phone mode
Support
Ye s
Travel Adapter Yes
CDROM Yes
Stereo Headset Yes
Data Cable Yes
T-Flash
(External Memory)
Yes ( Up to 32GB )

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
2.5 SW Features
Function Detail Item O / X Specification Etc.
OS OS O Windows Mobile
6.5

Circuit O Video Telephony
using 64kbps
CSD

Data
Packet O 
Infrared (IrDA) X 
Bluetooth O Ver. 2.1 + EDR 
Wi-Fi O 802.11 b and g 
USB O Ver. 2.0 (Full
Speed)

USB Mass
storage
X
Connectivity
RS232 X 
Voice Recording O 
X Digit Dial 
X Name Dial 
X Menu 
Voice Command
X Phonebook
Searching

Voice Function
Answering
machine
X Driving, Meeting,
user
define(absent)

O Total 2Gb Flash/ 1Gb DDR SDRAM +
external MicroSD
O Total User
Memory
128MB (w/o MicroSD)
O MMS 
O Pictures (Still
Image & Moving
Image)

O MP3 (Music
Contents)

O Java Contents 
O Wallpaper 
O Ringtone 
Memory User Memory
O external memory
(microSD)
support SDA2.0 specification, up to
32GB

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
Memory O User Memory + MicroSD 
Camera
Module
O 5 Mega Backend ISP 
Auto Focus O Still Mode AF 
Digital Zoom O 2X 
Capture
Resolution
O 320x240(QVGA)/
640x480(VGA) /
1280x960(1M) /
1600x1200(2M) /
2048x1536(3M) /
2560x1920(5M)

Continuous
Shot
O 320x240 Only 
Quality O Standard/Fine/Superfine 
Preview Image O QVGA( 320 X 240 ) & Full
Screen( 340 X 240 )

TV-Out X 
Flash X Not Available 
Filter O None/Negative/Sepia/Mono/A
qua/Emboss/Sketch/Red/Gre
en/Solarize

Timer O Off / 3 secs / 5 secs/10 secs 
O JPEG 
X Thumbnail 
JPEG
Encoding
O 320x240/640x480/1280x960/
1600x1200/2048x1536/2560x
1920

O JPEG JPEG
Decoding O Min, Max Supported by LGCamera
Gallery, LG My Stuff & MS
Pictures and Videos
Panorama
Shot
O Up to 3 images (1600x480) 
Camera
(Still Capture)















Album&Slide
show
O Slide show Supported by LG My Stuff
& MS Pictures and Videos

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
Movie Resolution O 400x240,320x240,176x144,128x96 
Filter O Same as the Still Capture 
Quality O Same as the Still Capture 
MPEG Visual Bit
Rate
O 350,284,199 Kbps 
Audio Encode O AMR-NB 
Audio Decode O AMR,AAC-LC Supported by
Windows
media
Movie Recode O Recode, Stop 
Movie Playback O Play, Stop, Pause Supported by
Windows
media
Stream Format
(Mux)
O 3gp 
Stream Format
(Demux)
O 3gp 
Recoding Time O Real Time Recoding 
Camera
(Movie
Capture)









TV-Out X 
Audio Voice Codec O AMR 
AAC /AAC+/ EAAC+ O 
MP3, WAV O 
WMA O 
Midi O Midi Type0, Midi Type1, SP-MIDI 
Music ringtone O MP3, AAC, AAC+, AAC-LC, XMF 1.01, AMR XMF is not
supported
AMR-NB O 
Music player skin X Windows Media Player 
FM Radio O USA/Japan band with RDS 
Multimedia








Speakerphone O 

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
MPEG4/H.263 O 
H.264 O 
WMV O WMV9 
Normal View O Moving Image Capture
& Movie Contents
contents size
Wide View O Full Screen mode 
Multimedia





Custom DTV
Zoom
X
File Viewer O doc, xls, ppt, gif, jpg 
Macromedia
Flash Lite
X Not Available LGE Flash Engine is specified to
UI (Not compatible)
e-Book/e-Comic
Book
X *.doc, *.jpg, *.gif E-book reader program is not
included in ROM. But user can
download in internet. WM product
recommend using Microsoft
Reader for PPC.
Other
Features


Flight Mode O 
O version 2.0 
O WML1.3 
O XHTML1.1 
Internet Browser WAP
(Windows
Mobile 6.0 IE
Mobile ) O HTML4.01 
MIDP O 2.1 
J2ME support O 
Game &
Contents
O Downloadable 
Java
CLDC O CLDC 1.1 
Flash Flash Game X 

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
H.263+AAC/AMR-NB O 
MPEG4+AAC/AMR-NB O 
Streaming
Service
WMV9 O Support WMV main and base
profile except advanced profile

O Forward Lock 
O Separate Delivery/ /
Superdistribution

DRM OMA DRM
O Combined Delivery - Count-
only

OTA OTA X 
RSSI O 4 level 
Battery Level O 5 level Yes
RTC O 
Multi Language O depending on build language.
MS limitation

Quick Access Mode O Hot key: Camera 
PLMN/Service
Indicator
O
Dimming Clock O Battery power
5s, 10s, 15s, 30s, 1min, 2min,
3min, 4min, 5min
External power
1min, 2min, 3min, 4min, 5min,
6min, 7min, 8min, 9min, 10min
Battery power
5s, 10s, 15s, 30s,
1min, 2min, 3min,
4min, 5min
External power
1min, 2min, 3min,
4min, 5min, 6min,
7min, 8min, 9min,
10min
Display
Dual Clock X Local Time / Selected Area
Time

Last Dialed Number X 
Last Received Number X 
Last Missed Number X 
Normal
Features
Scratch Pad Memory X 

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
Call Management Call Waiting O
Managemen Call Swap O
tCall Retrieve O
Auto Answer X
Automatic Redial X
Calling Line
Identification
O
Full Call divert X
Speed Dialing O
Last Number Redial X
Multiparty Call
(Conference Call)
O
Explicit Call Transfer O
Automatic Network
Selection
O
Manual Network
Selection
O
Network
Network Service
Status
O
DTMF Signaling ODTMF
DTMF Enable &
Disable
X
Key Tone Volume O 6 Level (Include Mute)
Ring Tone Volume O 6 Level (Include Mute)
Ring Tone Pattern O
Ring Type Silent O Vibrator & Ring (Indicator)
Earpiece Volume O 6 Level (Include Mute)
Audio
Mute O
Read Cell Broadcast O
Cell Broadcast
Categories
X
Cell Broadcast
Cell Broadcast
Message Language
O Supports filtering with
language IDs (German,English,Italian,French,Spanish,
Dutch,Swedish,Danish,Portuguese,Finnish,Norweggian
,Greek,Turkish,Hungarian,Polish,Czech)

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
Entry O 
Field O Home,Office,Mobile,e-
Mail,Fax, User define, etc

Numeric Store and Recall O 
Alphabetic Store O 
Alphabetic Recall O 
Scroll by alphabetic or
numeric order
O
Last Number Dialed O 
Last Number Missed O 
Last Number Received O 
Copy & Move O 
Fixed Dial Number X 
Barred Dial Number X 
Service Dial Number X 
Email Entry O 
Picture ID O Relating Photo caller ID 
Phone Book
My Name card O Bluetooth transmission
(OPP)

Last Call Timer X 
Last Call Charge Units X 
Total Call Timer X 
Total Charge Units X 
Call Cost



Visible, Audible Call
Time/Cost Indication
X 
O All Incoming Calls, 
O No Reply 
O On Busy, 
Call
Forwarding
O Not reachable 
O All Outgoing Calls, 
O International Calls, 
O Calls except to Home Country incoming Calls, 
Call
Barring
O All incoming Calls when roaming 
Supp. Services
Conference
Call
O up to 5 calls 
Plug In
Type
O
SIM Lock O 
SIM Toolkit O 
SIM
Prepaid
SIM
Operation
O

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
Read Message O EMS Not Support 
Write and Edit Message O 
Send and Receive
Message
O
Reply to Message O 
Forward Message O 
Extract Number from
Message
X
Message Status O 
Message Unread
Indicator
O
Settable Message Center
Number,
Reply Path and Validity
O
Visible and Audible
Message Receive
Alerting
O
Voice Mail O 
Settable Voice Mail
Center Number
O
Message Protocol O 
Message Overflow
Indicator
O
Message Center Number O 
Short Messaging
Help Menu X 
Picture Attachable O Max 300kbyte
Moving Picture
Attachable
O Video MMS Max 300kbyte
Voice Attachable O AMR 
Help Menu X 
Multimedia
Messaging
Others O 

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
IM O Windows Live Messenger client 
PC Compatable O 
Instant
Messaging
Service
Menu Option O 
O IMAP4 
O SMTP 
O POP3 
E-Mail Protocol
X Help Menu 
X Full Duplex PTT
X Half Duplex 
X Grouping 
X Status List 
X Help 
Voice Instant
Messaging
Service Menu Option
X Others 
Wallpaper O 
Screen Saver X 
Ringtones O 
Karaoke X 
Stutter Sound O 
Flip tone X 
Button tone O can be enable or disable button
press sound.

Sound Contents
Others X 

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
Development &
Test Facility
X
Field Test Facility X 
Display Software
Version
O
Miscellaneous
Function
IMEI O *#06# 
Language O Text Input
Predictive word
input
O T9 predictive supported. 
Schedule O 
To Do List O 
Memo O 
Scheduler
D-day counter X 
Send via
Bluetooth
O
Setting Local
Time
O
Display Two
Number of Cities
Time
X Dual clock 
World Time
Daylight saving O 
Unit converter X
Stop watch O
Calculator Calculation O 
Phone Book Sync O supported by MS ActiveSync 
Message Sync O supported by MS ActiveSync 
Multimedia
Contents Sync
O supported by MS ActiveSync 
PC Sync
Scheduler Sync O supported by MS ActiveSync 
DS X Sync ML
DM X 

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
Game O bubble breaker,
Soitaire

Menu Quick Access Mode (Profile) O 
Electrical Man Machine
Interface
X
External
Interface
Development and Test Facility X 
Restore Factory Setting O 
Read Software Version O 
Handset
Battery Charging Mode O USB/ TA Charging USB/ TA Charging
Emergency Call O 
Handset Lock O 
Security Code O 
SIM Lock O 
Security
Key guard X 
12/24 hour X 
Calendar O 
Time Zone O 
Alarm Manager O 
Dimming Clock O Battery power
5s, 10s, 15s, 30s,
1min, 2min, 3min,
4min, 5min
External power
1min, 2min, 3min,
4min, 5min, 6min,
7min, 8min, 9min,
10min
Battery power
5s, 10s, 15s, 30s,
1min, 2min, 3min,
4min, 5min
External power
1min, 2min, 3min,
4min, 5min, 6min,
7min, 8min, 9min,
10min
Power-off Alarm X 
Real Time Clock
On Alarm Event O Display 

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
Game O bubble breaker, Soitaire 
Menu Quick Access Mode
(Profile)
O
Electrical Man
Machine Interface
X
External
Interface
Development and Test
Facility
X
Restore Factory
Setting
O
Read Software Version O 
Handset
Battery Charging
Mode
O USB/ TA Charging USB/ TA Charging
Emergency Call O 
Handset Lock O 
Security Code O 
SIM Lock O 
Security
Key guard X 
12/24 hour X 
Calendar O 
Time Zone O 
Alarm Manager O 
Dimming Clock O Battery power
5s, 10s, 15s, 30s, 1min,
2min, 3min, 4min, 5min
External power
1min, 2min, 3min, 4min,
5min, 6min, 7min, 8min,
9min, 10min
Battery power
5s, 10s, 15s, 30s,
1min, 2min, 3min,
4min, 5min
External power
1min, 2min, 3min,
4min, 5min, 6min,
7min, 8min, 9min,
10min
Power-off Alarm X 
Real Time Clock
On Alarm Event O Display 