LG GX500 User manual

Service Manual Model : GX500
Internal Use Only
Service Manual
GX500
Date: March, 2010 / Issue 1.0

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Copyright © 2010 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
1.3 Abbreviations................................................................................... 7
2. PERFORMANCE..................................................9
2.1 H/W Features.................................................................................... 9
2.2 Technical Specification...............................................................10
3. TECHNICAL BRIEF............................................17
3.1 GX500 Functional Block diagram...........................................17
3.2 Dual Baseband Processor (BBP) Introduction...................18
3.3 Power management IC ..............................................................38
3.4 Power ON/OFF...............................................................................46
3.5 Dual SIM & u-SD Interface.........................................................48
3.6 Memory............................................................................................50
3.7 LCD Display.....................................................................................53
3.8 Keypad Switching & Scanning................................................54
3.9 LCD back-light illumination......................................................55
3.10 JTAG & ETM interface connector .........................................56
3.11 Audio...............................................................................................57
3.12 Charging circuit ..........................................................................59
3.13 WI-FI & BLUETOOTH & FMradio............................................60
3.14 5pin Micro USB Interface connector..................................63
3.15 Triaxial, digital acceleration sensor.....................................64
3.16 General Description..................................................................66
3.17 Receiver part................................................................................68
3.18 Transmitter part..........................................................................69
3.19 RF synthesizer..............................................................................70
3.20 DCXO...............................................................................................70
3.21 Front End Module control......................................................71
3.22 Power Amplifier Module.........................................................72
3.23 PAM Schematic ...........................................................................73
4. TROUBLE SHOOTING ......................................74
4.1 Trouble shooting test setup.....................................................74
4.2 Power on Trouble..........................................................................75
4.3 Charging trouble ..........................................................................78
4.4 LCD display trouble .....................................................................80
4.5 Camera Trouble.............................................................................82
4.6 Receiver & Speaker trouble ......................................................84
4.7 Microphone trouble....................................................................86
4.8 Vibrator trouble.............................................................................87
4.9 SIM & uSD trouble ........................................................................89
4.10 Touch trouble...............................................................................92
4.11 LCD LED trouble .........................................................................93
4.12 Trouble shooting of Receiver part.......................................94
4.13 Trouble shooting of Transmitter part.............................. 100
4.14 Trouble shooting of WI-FI/BT/FM part............................ 109
5. DOWNLOAD & S/W UPGRADE......................112
6. BLOCK DIAGRAM...........................................120
7. CIRCUIT DIAGRAM ........................................121
8. BGA Pin Map..................................................129
9. PCB LAYOUT...................................................139
10. RF CALIBRATION .........................................147
10.1 Test Equipment Setup........................................................... 147
10.2 Calibration Step....................................................................... 147
11. STAND ALONE TEST ....................................152
11.1 SIM1 TEST ................................................................................... 152
11.2 SIM2 TEST ................................................................................... 159
12. ENGINEERING MODE ..................................161
13. EXPLODED VIEW & REPLACEMENT
PART LIST ....................................................163
13.1 EXPLODED VIEW...................................................................... 163
13.2 Replacement Parts.................................................................. 165
13.3 Accessory ................................................................................... 189

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LGE Internal Use Only Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
1. INTRODUCTION
GX500 Operational Description Revision A
LG Electronics 5/143 LGE Property
I. Introduction
1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the features
of the GX500.
1.2 Regulatory Information
1.2.1 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 you’re 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. LGE 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. LGE will not be responsible for any charges that result from such unauthorized
use.
1.2.2 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.
1.2.3 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 GX500 or compatibility with the network, the telephone
company is required to give advanced written notice to the user, allowing the user to take appropriate steps
to maintain telephone service.
1.2.4 Maintenance Limitations
Maintenance limitations on the GX500 must be performed only at the LGE or its authorized agents. 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.
1.2.5 Notice of Radiated Emissions
The GX500 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 © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
GX500 Operational Description Revision A
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1.2.6 Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly different.
1.2.7 Interference and Attenuation
An GX500 may interfere with sensitive laboratory equipment, medical equipment, etc. Interference from
unsuppressed engines or electric motors may cause problems.
1.2.8 Electrostatic Sensitive Devices
ATTENTION
Boards, which contains 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 such as EEPROM to the factory, use the protective
package as described.

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
GX500 Operational Description Revision A
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1.3 ABBREVIATION
For the purposes of this manual, following abbreviations apply:
୛APC Automatic Power Control
୛BB Baseband
୛BER Bit Error Ratio
୛CC-CV Constant Current – Constant Voltage
୛CLA Cigar Lighter Adapter
୛DAC Digital to Analog Converter
୛DCS Digital Communication System
୛dBm dB relative to 1 milli-watt
୛DSP Digital Signal Processing
୛EEPROM Electrical Erasable Programmable Read-Only Memory
୛EGPRS Enhanced General Packet Radio Service
୛EL Electroluminescence
୛ESD Electrostatic Discharge
୛FPCB Flexible Printed Circuit Board
୛GMSK Gaussian Minimum Shift Keying
୛GPIB General Purpose Interface Bus
୛GPRS General Packet Radio Service
୛GSM Global System for Mobile Communications
୛IPUI International Portable User Identity
୛IF Intermediate Frequency
୛LCD Liquid Crystal Display
୛LDO Low Drop Output
୛LED Light Emitting Diode
୛LGE LG Electronics
୛OPLL Offset Phase Locked Loop
୛PAM Power Amplifier Module
୛PCB Printed Circuit Board
୛PGA Programmable Gain Amplifier
୛PLL Phase Locked Loop
୛PSTN Public Switched Telephone Network
୛RF Radio Frequency
୛RLR Receiving Loudness Rating
୛RMS Root Mean Square
୛RTC Real Time Clock
୛SAW Surface Acoustic Wave
୛SIM Subscriber Identity Module
୛SLR Sending Loudness Rating
୛SRAM Static Random Access Memory
୛STMR Side Tone Masking Rating
୛TA Travel Adapter
୛TDD Time Division Duplex
୛TDMA Time Division Multiple Access
୛UART Universal Asynchronous Receiver/Transmitter

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LGE Internal Use Only Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
GX500 Operational Description Revision A
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୛VCO Voltage Controlled Oscillator
୛DCXO Digitally Controled Crystal Oscillator
୛WAP Wireless Application Protocol
ଝ8PSK 8 Phase Shift Keying

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
2. PERFORMANCE
GX500 Operational Description Revision A
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II. General Performance
2.1 H/W Feature
Item Feature Comment
Standard Battery Lithium-Ion Polymer, 15000mAh
AVG TCVR Current 265mA typ @PL5
Standby Current 3.7 mA typ @PP5
Talk time 7 hours (GSM TX Level 7)
Standby time Over 390 hours (Paging Period:5, RSSI: -85dBm)
Charging time Under 3.5 hours
RX Sensitivity EGSM/GSM850:-105dBm˨,DCS/PCS:-105dBm˨
TX output power EGSM/GSM850 : 33dBm (@PL 5)
DCS/PCS: 30dBm (@PL 0)
GPRS compatibility Class 12
SIM card type 3V Small
Display Main 240 u400 pixels, 3”WQVGA, 262K color
Status Indicator Send Key, Shortcut Key, Volume Up/Down Key,
PWR Key, Camera Key, Lock Key
ANT Built in antenna
EAR Phone Jack 5pin Micro USB
PC Synchronization Yes
Speech coding HR/EFR/FR/AMR
Data and Fax Yes
Vibrator Yes
Buzzer No
Voice Recoding Yes
C-Mic Yes
Receiver Yes
Travel Adapter Yes
Options Bluetooth hands-free kit, Data Kit

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Only for training and service purposes
2. PERFORMANCE
GX500 Operational Description Revision A
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2.2 Technical specification
Item Description Specification
1 Frequency Band
GSM850
TX: 824 + 0.2 x n MHz
RX: 869 + 0.2 x n MHz ( n = 128 ~ 251 )
EGSM
TX: 890 + 0.2 x (n-1024) MHz
RX: 935 + 0.2 x (n-1024) MHz ( n = 975 ~ 1023 /1 ~ 124)
DCS1800
TX: 1710 + ( n-511 ) u0.2 MHz (n = 512 a885)
RX: TX + 95 MHz
PCS1900
TX: 1850.2 + ( n-512 ) u0.2 MHz (n = 512 a810)
RX: TX + 80MHz
2 Phase Error RMS < 5 degrees
Peak < 20 degrees
3 Frequency Error < 0.1ppm
GSM850/EGSM
Level Power Toler. Level Power Toler.
5 33 dBm ±2dB 13 17 dBm ±3dB
6 31 dBm ±3dB 14 15 dBm ±3dB
7 29 dBm ±3dB 15 13 dBm ±3dB
8 27 dBm ±3dB 16 11 dBm ±5dB
9 25 dBm ±3dB 17 9 dBm ±5dB
10 23 dBm ±3dB 18 7 dBm ±5dB
11 21 dBm ±3dB 19 5 dBm ±5dB
12 19 dBm ±3dB
DCS1800/PCS1900
Level Power Toler. Level Power Toler.
0 30 dBm ±2dB 8 14 dBm ±3dB
1 28 dBm ±3dB 9 12 dBm ±4dB
2 26 dBm ±3dB 10 10 dBm ±4dB
3 24 dBm ±3dB 11 8 dBm ±4dB
4 22 dBm ±3dB 12 6 dBm ±4dB
5 20 dBm ±3dB 13 4 dBm ±4dB
6 18 dBm ±3dB 14 2 dBm ±5dB
4 Power Level
7 16 dBm ±3dB 15 0 dBm ±5dB

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
GX500 Operational Description Revision A
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GSM850/EGSM
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ 1,200 -60
1,200 ~ 1,800 -60
1,800 ~ 3,000 -63
3,000 ~ 6,000 -65
6,000 -71
DCS1800/PCS1900
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ 1,200 -60
1,200 ~ 1,800 -60
1,800 ~ 3,000 -65
3,000 ~ 6,000 -65
5 Output RF Spectrum
(due to modulation)
6,000 -73
GSM850/EGSM
Offset from Carrier (kHz) Max. (dBm)
400 -19
600 -21
1,200 -21
1,800 -24
DCS1800/PCS1900
Offset from Carrier (kHz) Max. (dBm)
400 -22
600 -24
1,200 -24
6 Output RF Spectrum
(due to switching transient)
1,800 -27