LG LG-A155 User manual

Service Manual Model : LG-A155
Internal Use Only
Service Manual
LG-A155
Date: October, 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...............................................................11
3. TECHNICAL BRIEF.............................................................16
3.1 Digital Main Processor................................................................16
3.2 Power Management....................................................................21
3.3 FEM with integrated Power Amplifier Module
(SKY77547, U303) .........................................................................26
3.4 Clocks ................................................................................................28
3.5 RFSYS of MT6253 (U102) ...........................................................30
3.6 MEMORY(PF38F4050M0Y3DE, U101)..................................32
3.7 BT Module .......................................................................................35
3.8 SIM Card Interface........................................................................39
3.9 Micro-SD Card Interface.............................................................41
3.10 LCD Interface ...............................................................................44
3.11 Battery Charger Interface .......................................................46
3.12 Keypad Interface........................................................................47
3.13 Audio Front-End.........................................................................50
3.15 KEY BACLKLIGHT LED Interface............................................53
3.16 Vibrator Interface .......................................................................54
4. TROUBLE SHOOTING .......................................................55
4.1 RF Component...............................................................................55
4.2 RX Trouble .......................................................................................56
4.3 TX Trouble........................................................................................60
4.4 Power On Trouble.........................................................................64
4.5 Charging Trouble..........................................................................67
4.6 Vibrator Trouble.............................................................................69
4.7 LCD Trouble.....................................................................................71
4.9 Speaker Trouble ............................................................................75
4.10 Earphone Trouble ......................................................................77
4.11 Receiver Trouble.........................................................................79
4.12 Microphone Trouble.................................................................81
4.13 SIM Card Interface Trouble.....................................................83
4.14 SIM2 Card Interface Trouble..................................................85
4.15 KEY backlight Trouble ..............................................................87
4.16 Micro SD (uSD) Trouble............................................................89
4.17 Bluetooth Trouble......................................................................91
4.18 FM Radio Trouble .......................................................................93
5. DOWNLOAD......................................................................95
6. BLOCK DIAGRAM........................................................... 108
7. CIRCUIT DIAGRAM ........................................................ 109
8. BGA PIN MAP ................................................................. 115
9. PCB LAYOUT................................................................... 117
10. ENGINEERING MODE .................................................. 123
11. RF CALIBRATION ......................................................... 125
11.1 Configuration of Tachyon.................................................... 125
11.2 How to use Tachyon............................................................... 127
12 EXPLODED VIEW & REPLACEMENT PART LIST .......... 129
12.1 EXPLODED VIEW...................................................................... 129
12.2 Replacement Parts.................................................................. 131
12.3 Accessory ................................................................................... 142

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

- 5 -
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
1. INTRODUCTION
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ \VX[W
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 this phone 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.
D. Maintenance Limitations
Maintenance limitations on this model 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.
1. INTRODUCTION
1. INTRODUCTION

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LGE Internal Use Only Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ ]VX[W
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.
F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.
G. Interference and Attenuation
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.
1. INTRODUCTION

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ ^VX[W
1.3 Abbreviations
For the purposes of this manual, following abbreviations apply:
Offset Phase Locked LoopOPLL
Light Emitting DiodeLED
Low Drop OutputLDO
Liquid Crystal DisplayLCD
Intermediate FrequencyIF
International Portable User IdentityIPUI
Global System for Mobile CommunicationsGSM
General Purpose Interface BusGPIB
Gaussian Minimum Shift KeyingGMSK
Flexible Printed Circuit BoardFPCB
Electrostatic DischargeESD
Electrical Erasable Programmable Read-Only MemoryEEPROM
Digital Signal ProcessingDSP
dB relative to 1 milli wattdBm
Digital Communication SystemDCS
Digital to Analog ConverterDAC
Constant Current – Constant VoltageCC-CV
Bit Error RatioBER
BasebandBB
Automatic Power ControlAPC
1. INTRODUCTION

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LGE Internal Use Only Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ _VX[W
Wireless Application Protocol
WAP
Voltage Control Temperature Compensated Crystal OscillatorVCTCXO
Voltage Controlled OscillatorVCO
Universal Asynchronous Receiver/TransmitterUART
Time Division Multiple AccessTDMA
Time Division DuplexTDD
Travel AdapterTA
Side Tone Masking RatingSTMR
Pseudo SRAMPSRAM
Static Random Access MemorySRAM
Sending Loudness RatingSLR
Subscriber Identity ModuleSIM
Surface Acoustic WaveSAW
Real Time ClockRTC
Root Mean SquareRMS
Receiving Loudness RatingRLR
Radio FrequencyRF
Public Switched Telephone NetworkPSTN
Phase Locked LoopPLL
Programmable Gain AmplifierPGA
Printed Circuit BoardPCB
Power Amplifier ModulePAM
1. INTRODUCTION

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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
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ `VX[W
2.1 H/W Features
2. SYSTEM SPECIFICATION
Item Feature Comment
Standard Battery Li-ion Polymer, 3.7V 950mAh
Stand by TIME Up to 200 hrs : Paging Period 5, RSSI 85dBm
Talk time Up to 200min : GSM Tx Level 7
Stand by time Up to 200 hours (Paging Period: 5, RSSI: -85 dBm)
Charging time Approx. 3 hours
RX Sensitivity GSM, EGSM: -109dBm, DCS: -109dBm
TX output power GSM, EGSM: 32.3dBm(Level 5),
DCS , PCS: 29.5dBm(Level 0)
SIM card type 3V Small
Display MAIN : TFT 176 Ý220 pixel 262K Color
Status Indicator
Hard icons. Key Pad
0 ~ 9, #, *, Up/Down Navigation Key
Menu Key, Clear Key, Back Key, Confirm Key
Send Key, Soft Key(Left/Right)
Volume Key(Up/Down), PWR Key, Camera Key
ANT Internal
EAR Phone Jack Yes
PC Synchronization Yes
Speech coding EFR/FR/HR
Data and Fax Yes
GPRS compatibility Class 10
Vibrator Yes
Loud Speaker Yes
Voice Recoding Yes
Microphone Yes
2. SYSTEM SPECIFICATION

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LGE Internal Use Only Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ XWVX[W
Travel Adapter Yes
Speaker/Receiver 18x12ȰSpeaker/ Receiver
MIDI SW MIDI (Mono SPK)
Item Feature Comment
Camera 0.3M
Bluetooth / FM Radio Bluetooth version 2.1 / 76~108MHz supported
16ȰSpeaker/ 12 x 7 Receiver
2. SYSTEM SPECIFICATION
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ XWVX[W
Travel Adapter Yes
Speaker/Receiver 18x12ȰSpeaker/ Receiver
MIDI SW MIDI (Mono SPK)
Item Feature Comment
Camera 0.3M
Bluetooth / FM Radio Bluetooth version 2.1 / 76~108MHz supported
16ȰSpeaker/ 12 x 7 Receiver
2. SYSTEM SPECIFICATION

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Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
ʹΠΡΪΣΚΘΙΥι ͽ͸ͶΝΖΔΥΣΠΟΚΔΤͺΟΔͲΝΝΣΚΘΙΥΣΖΤΖΣΧΖΕ
΀ΟΝΪΗΠΣΥΣΒΚΟΚΟΘΒΟΕΤΖΣΧΚΔΖΡΦΣΡΠΤΖΤ
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ XXVX[W
2.2 Technical Specification
Item Description Specification
1 Frequency Band
GSM850 EGSM
TX: 824 ~ 849 MHz TX: 880 ~ 915MHz
RX: 869 ~ 894 MHz RX: 925 ~ 960 MHz
DCS
TX: 1710 ~ 1785 MHz
RX: 1805 ~ 1880 MHz
PCS
TX: 1850 ~ 1910 MHz
RX: 1930 ~ 1990 MHz
2 Phase Error RMS < 5 degrees
Peak < 20 degrees
3 Frequency Error < 0.1 ppm
4 Power Level
Level Power Toler. Level Power Toler.
6 31dBm ·3dB 14 15dBm ·3dB
7 29dBm ·3dB 15 13dBm ·3dB
8 27dBm ·3dB 16 11dBm ·5dB
9 25dBm ·3dB 17 9dBm ·5dB
10 23dBm ·3dB 18 7dBm ·5dB
11 21dBm ·3dB 19 5dBm ·5dB
12 19dBm ·3dB
GSM850/EGSM
5 33dBm ·2dB 13 17dBm ·3dB
Level Power Toler. Level Power Toler.
1 28dBm ·3dB 9 12dBm ·4dB
2 26dBm ·3dB 10 10dBm ·4dB
3 24dBm ·3dB 11 8dBm ·4dB
4 22dBm ·3dB 12 6dBm ·4dB
5 20dBm ·3dB 13 4dBm ·4dB
6 18dBm ·3dB 14 2dBm ·5dB
7 16dBm ·3dB 15 0dBm ·5dB
DCS/PCS
0 30dBm ·2dB 8 14dBm ·3dB
2. SYSTEM SPECIFICATION