LG GU280 User manual

Service Manual Model : GU280/GU285
Internal Use Only
Service Manual
GU280/GU285
Date: October, 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 : Solution....................................................7
2.4 Feature.......................................................................8
2.5 HW Spec...................................................................10
3. Technical Brief .............................................13
3.1. General Description ..................................................13
3.2. WCDMA Part ............................................................14
3.3. EDGE/GPRS/GSM RF block........................................19
3.5. Control Flow.............................................................24
3.6 General Description ...................................................25
3.7 Power management ..................................................35
4. TROUBLE SHOOTING..................................... 38
4.1 RF Component ..........................................................38
4.2 RF Path ....................................................................39
4.3 Trouble Shooting of GSM Part (GSM850/900/1800/1900)
......................................................................................40
4.4 Trouble Shooting of WCDMA Part................................48
4.5 Checking Bluetooth Block ..........................................55
4.6 Checking FM Radio Block ..........................................58
4.7 Base band part..........................................................61
4.8 Charger Troubleshooting ............................................63
4.9 USB Troubleshooting..................................................64
4.10 USIM Detect Troubleshooting....................................66
4.11 Camera Troubleshooting ..........................................68
4.12 Main Keypad Backlight Troubleshooting ....................70
4.13 Sub Keypad Backlight Troubleshooting......................71
4.14 LCD Troubleshooting................................................73
4.15 Vibrator...................................................................74
4.16 Receiver Path..........................................................75
4.17 Headset path...........................................................77
4.18 Speaker phone path ................................................79
4.19 Main microphone ....................................................81
4.20 Headset microphone................................................83
5. Downloading ................................................ 85
5.1 Introduction...............................................................85
5.2 Downloading Procedure.............................................86
5.3 Troubleshooting Download Errors..............................101
5.4 Caution...................................................................106
6. Block Diagram ........................................... 107
7. CIRCUIT DIAGRAM...................................... 109
8. BGA Pin Map .............................................. 117
9. PCB LAYOUT ............................................... 121
10. CALIBRATION............................................ 127
10.1 Configuration of directory.......................................127
10.2 How to use Tachyon...............................................129
11. EXPLODED VIEW & REPLACEMENT
PART LIST ................................................131
11.1 EXPLODED VIEW ...................................................131
11.2 Replacement Parts ................................................133
11.3 Accessory .............................................................150

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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
BL20
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
BL20
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
GU280 : WCDMA2100+EGSM/GSM850/DCS/PCS
(GPRS Class 12 / EDGE Class 12)
2.2 Supporting Standard
WAP 2.0, JAVA(MIDP 2.1 CLDC 1.1)Application Standard
WCDMA(FDD1) TX : 1920 – 1980 MHz
WCDMA(FDD1) RX : 2110 – 2170 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
Frequency Range
WCDMA(FDD1)/EGSM/GSM850/DCS1800/PCS1900
with seamless handover
Phase 2+(include AMR)
SIM Toolkit : Class 1, 2, 3, C-E
Supporting Standard
CommentFeatureItem
2.3 Main Parts : Solution
QSC6240 : QualcommRF Chip
QSC6240 : QualcommAnalog Baseband
QSC6240 is an one-chip
solution(DB + AB + RF +
PM)
QSC6240 : QualcommDigital Baseband
CommentPart NameItem

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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
EDGE Class 12EDGE compatibility
GPRS Class 12GPRS compatibility
E2 (GSM900)
E2 (PCS)
E2 (DCS)
GSM 900 : 27 dBm
DCS 1800 : 26 dBm
PCS 1900 : 26 dBm
EDGE
Class3(WCDMA)
Class4 (EGSM)
Class4 (GSM850)
Class1 (PCS)
Class1 (DCS)
WCDMA : 24dBm/3.84MHz,+1/-3dBm
EGSM : 33dBm
GSM850 : 33 dBm
DCS 1800 : 30 dBm
PCS 1900 : 30 dBm
WCDMA/
GSM/
GPRS
TX output
power
WCDMA(FDD1) < -105 dBm
EGSM < -105 dBm
GSM850 < -105 dBm
DCS 1800 < -105 dBm
PCS 1900 <-105 dBm
RX sensitivity
@ Power Level 5 (2G)
@ Tx = 12dBm (3G)
2G : Over 180mins
3G : Over 180 mins
Talk time
@ Power Off / 900mAh3 hrsCharging time
@ Paging Period 5 (2G)
@ DRX 1.28 (3G)
2G : Over 320 hrs
3G : Over 250 hrs
Stand by time
Staggered 10 Layers , 0.8tPCB
TBDVolume
With Battery115gWeight
Standard :
96.0 x 45.7 x 14.9mm
Size
2) Packing Type : Inner Pack
1) Capacity
Standard : Li-Ion, 900mAh
Battery
Slide typeForm Factor
CommentFeatureItem
2.4 Feature

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
NoT-Flash
(External Memory)
OptionData Cable
OptionStereo Headset
NoCDROM
YesTravel Adapter
YesSpeaker Phone mode
Support
YesVoice Recording
MPEG4, H.263,Camcorder
MPEG4, H.263, WMV9Video Player
MP3/ WMA/AAC/HE-AAC/EAAC+Music Player
EDR 2.0Blue Tooth
Built in VibratorVibrator
NoData & Fax
FR, EFR, HR,AMRSpeech coding
NAND Flash : 1Gbit
SDRAM : 512Gbit
Memory
YesPC synchronization
3.5Phi, 4 Pole, StereoEar Phone Jack
5 PinSystem connector
Main : Internal Fixed TypeANT
Slide Key pad : 11
Main Key pad : 15
Keypad
1.3 CMOS CameraBuilt-in Camera
Main LCD
TFT Main LCD(2’, 176 x 220)
Display
Plug-In SIM
3V /1.8V
SIM card type

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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 HW Spec.
GSM Transmitter/Receiver spec.
Item Specification
Phase Error Rms : 5°
Peak : 20 °
Frequency Error GSM : 0.1 ppm
DCS/PCS : 0.1 ppm
EMC(Radiated Spurious Emission
Disturbance) GSM/DCS : < -28dBm
Transmitter Output power and Burst
Timing
GSM : 5dBm – 33dBm ±3dB
DCS/PCS : 0dBm – 30dBm ±3dB
Burst Timing <3.69us
Spectrum due to modulation out to less
than 1800kHz offset
200kHz : -36dBm
600kHz : -51dBm/-56dBm
Spectrum due to modulation out to larger
than 1800kHz offset to the edge of the
transmit band
GSM :
1800-3000kHz :< -63dBc(-46dBm)
3000kHz-6000kHz : <-65dBc(-46dBm)
6000kHz < : < -71dBc(-46dBm)
DCS :
1800-3000kHz :< -65dBc(-51dBm)
6000kHz < : < -73dBc(-51dBm)
Spectrum due to switching transient 400kHz : -19dBm/-22dBm(5/0), -23dBm
600kHz : -21dBm/-24dBm(5/0), -26dBm
Reference Sensitivity – TCH/FS Class II(RBER) : -105dBm(2.439%)
Usable receiver input level range 0.012(-15 - -40dBm)
Intermodulation rejection – Speech
channels
±800kHz, ±1600kHz
: -98dBm/-96dBm (2.439%)
AM Suppression
-GSM : -31dBm - DCS : -29dBm -98dBm/-96dBm (2.439%)
Timing Advance ±0.5T

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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
WCDMA Transmitter spec.
Item Specification
Transmit Frequency 1920 MHz ~ 1980 MHz
Maximum Output Power +24 dBm / 3.84 MHz, +1 / -3 dB
Frequency Error within ±0.1 PPM
Open Loop Power
Control
Normal Conditions : within ±9 dB,
Extreme Conditions : within ±12 dB
Minimum Transmit Power < -50 dBm /3.84 MHz
Occupied Bandwidth < 5 MHz at 3.84 Mcps (99% of power)
Adjacent Channel
Leakage
Power Ratio (ACLR)
> 33 dB @ ±5 MHz,
> 43 dB @ ±10 MHz
Spurious Emissions
|f-fc| > 12.5 MHz
< -36 dBm / 1 kHz RW @ 9 kHz ≤f < 150 kHz
< -36 dBm / 10 kHz RW @ 150 KHz ≤f < 30 MHz
< -36 dBm / 100 kHz RW @ 30 MHz ≤f < 1 GHz
< -30 dBm / 1 MHz RW @ 1 GHz ≤f < 12.75 GHz
< -41 dBm / 300 kHz RW @ 1893.5 MHz < f < 1919.6 MHz
< -67 dBm / 100 kHz RW @ 925 MHz ≤f ≤935 MHz
< -79 dBm / 100 kHz RW @ 935 MHz < f ≤960 GHz
< -71 dBm / 100 kHz RW @ 1805 MHz ≤f ≤1880 MHz
Transmit Intermodulation < -31 dBc @ 5 MHz & < -41 dBc @ 10 MHz
when Interference CW Signal Level = -40 dBc
Error Vector Magnitude < 17.5 %, when Pout ≥-20 dBm
Peak Code Domain Error < -15 dB at Pout t-20 dBm