LG D686 User manual

Internal Use Only
Service Manual
LG-D686
Date : September, 2013 / Issue 0.9

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Only for training and service purposes
LGE Internal Use Only
Table Of Contents
1. INTRODUCTION..................................................................... 3
1.1 Purpose ........................................................................................................3
1.2 Regulatory Information.........................................................................3
2. PERFORMANCE...................................................................... 5
2.1 Product Name............................................................................................5
2.2 Supporting Standard..............................................................................5
2.3 Main Parts : GSM Solution.....................................................................5
2.4 HW Features ...............................................................................................6
2.5 HW SPEC ......................................................................................................8
2.6 D686 Figures ........................................................................................... 22
3. TROUBLE SHOOTING .......................................................... 23
3.1 WCDMA Rx Part...................................................................................... 23
3.2 WCDMA Tx Part ...................................................................................... 37
3.3 GSM Rx Part ............................................................................................. 54
3.4 GSM Tx Part Troubleshooting........................................................... 67
3.5 Power ......................................................................................................... 75
3.6 Charging ................................................................................................... 80
3.7 USB.............................................................................................................. 82
3.8 Audio.......................................................................................................... 83
3.9 6 AXIS Sensor .......................................................................................... 97
3.10 Proximity Sensor ...............................................................................100
3.11 Touch Sensor ......................................................................................102
3.12 Vibrator .................................................................................................104
3.13 Camera..................................................................................................106
3.14 LCD .........................................................................................................110
3.15 BT/Wi...................................................................................................113
3.16 GPS Part ................................................................................................117
3.17 FM Radio...............................................................................................122
3.18 IRRC ........................................................................................................124
4. DOWNLOAD.......................................................................127
5. BLOCK DIAGRAM..............................................................144
6. CIRCUIT DIAGRAM ............................................................152
7. BGA PIN MAP.....................................................................161
8. PCB LAYOUT.......................................................................165
9. CALIBRATION.....................................................................167
10. HIDDEN MENU.................................................................186
11. DISASSEMBLE GUIDE......................................................210
12. EXPLODED VIEW & REPLACEMENT PART LIST .............214

- 3 - Copyright © 2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
1. INTRODUCTION
- 4 -
This manual provides the information necessary to repair, calibration, description and download the features
of this model.
1.1 Purpose
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.
1.2 Regulatory Information
A. Security
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 Limitation
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 Emission
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.
1. Introduction

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Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
- 5 -
ATTENTION
H. Electrostatic Sensitive Devices
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
A phone may interfere with sensitive laboratory equipment, medical equipment, etc. Interference from
unsuppressed engines or electric motors may cause problems.
G. Interference and Attenuation
F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.

2. PERFORMANCE
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LGE Internal Use Only
2. PERFORMANCE
2.1 Product Name
LG-D686 : WCDMA 850/900/1900/2100+GSM850/EGSM/DCS/PCS
(HSUPA 5.8Mbps(cat6)/HSDPA 7.2Mbps(cat8)/GPRS Class12/EDGE Rx only Class12)
2.2 Supporting Standard
LG-D685 Product SPEC
4
2.1 Product Name
LG-D685 : WCDMA 850/900/1900/2100+GSM850/EGSM/DCS/PCS
(HSUPA 5.8Mbps(cat6)/HSDPA 7.2Mbps(cat8)/GPRS Class12/EDGE Rx only Class12)
2.2 Supporting Standard
Supporting Standard
WCDMA(FDD1,2,5,8)/EGSM/GSM850/DCS1800/PCS1900
with seamless handover
Phase 2+(include AMR)
SIM Toolkit : Class 1, 2, 3, C-E
Frequency Range
WCDMA(FDD1) TX : 1920 – 1980 MHz
WCDMA(FDD1) RX : 2110 – 2170 MHz
WCDMA(FDD2) TX : 1850 – 1908 MHz
WCDMA(FDD2) RX : 1930 –1990 MHz
WCDMA(FDD5) TX : 824 – 849 MHz
WCDMA(FDD5) RX : 869 – 894 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
2.3 Main Parts :
Item Part Name Comment
AP Chip MT6577 (MTK)
CP Chip MT6577 (MTK)
LG-D685 Product SPEC
4
2.1 Product Name
LG-D685 : WCDMA 850/900/1900/2100+GSM850/EGSM/DCS/PCS
(HSUPA 5.8Mbps(cat6)/HSDPA 7.2Mbps(cat8)/GPRS Class12/EDGE Rx only Class12)
2.2 Supporting Standard
Supporting Standard
WCDMA(FDD1,2,5,8)/EGSM/GSM850/DCS1800/PCS1900
with seamless handover
Phase 2+(include AMR)
SIM Toolkit : Class 1, 2, 3, C-E
Frequency Range
WCDMA(FDD1) TX : 1920 – 1980 MHz
WCDMA(FDD1) RX : 2110 – 2170 MHz
WCDMA(FDD2) TX : 1850 – 1908 MHz
WCDMA(FDD2) RX : 1930 –1990 MHz
WCDMA(FDD5) TX : 824 – 849 MHz
WCDMA(FDD5) RX : 869 – 894 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
2.3 Main Parts :
Item Part Name Comment
AP Chip MT6577 (MTK)
CP Chip MT6577 (MTK)
2.3 Main Parts : GSM Solution

2. PERFORMANCE
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LGE Internal Use Only
2.4 HW Features
LG-D685 Product SPEC
5
2.4 HW Features
List Type / Spec.
1. Phone Type DOP Type
2. Size 150.25 x 76.94 x 9.43mm
3. Weight 163.9 g
4. Battery Brazil : 3,040mAh ( typ.)
Other Country : 3,140mAh ( typ.), 3,040mAh(min) (Li-Ion)
5.Chipset MT6577
6. Memory 8GB(EMMC) +8Gb(LPDDR2)
7. LCD
Size 5.5 inch
Dot 540(H) X 960(V)
Color 16.7M colors
Display Type Active matrix TFT, Transmissive Type
NTSC Typ. 70%
Contrast Ratio Typ. 1000:1
Pixel Pitch 0. 042mm (201.6ppi)
Color temperature 5000 ~ 9000(K) ( typ. 6500K)
8. Main Camera (8M)
Type CMOS image sensor
Resolution 3296(H) X 2512(V) pixels.
Frame Rate 22.5 fps@ Full Size(3280*2464)
View Angle 71.4˚ ± 1˚ (Diagonal)
Image Scaling Down 8M(3264x2448), W6M(3264x1836),

2. PERFORMANCE
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Only for training and service purposes
LGE Internal Use Only
LG-D685 Product SPEC
6
5M(2592x1944), 1M(1280x960)
Pixel x size 1.1um X 1.1um (square pixel)
10. Audio
1) MIDI MIDI
2) Mono 15 X 11 X 3T Speaker
3) Receiver 13 X 07 X 2.7T Wideband Receiver
11. Bluetooth
Effective Distance 10M
Distance 0 m ~ 10 m (depend on environment)
12. WLAN
standard IEEE 802.11 b/g/n
Throughput Max 40Mbps (SDIO Driver performance)
depend on environment 0 ~ 50m (depend on environment)
13. GPS type A-GPS, GNSS

2. PERFORMANCE
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Only for training and service purposes
LGE Internal Use Only
2.5. HW SPEC
1) WCDMA transmitter specication
LG-D685 Product SPEC
7
2.5. HW SPEC.
1) WCDMA transmitter specification
Item Spec. Min Typ. Max Unit
Maximum Output
Power Power class Ⅲ21.0 23.0 25.0 dBm/3.84MHz
Frequency
Accuracy - -200 - +200 Hz
Minimum Output
Power - - - -50 dBm/3.84MHz
Occupied
Bandwidth - - - 4.6 MHz
Adjacent Channel
Leakage Power
Ratio
Δf = ±5MHz - - -33 dBm/3.84MHz
Δf = ±10MHz - - -43 dBm/3.84MHz
Error Vector
Magnitude(EVM) - - - 17 %
Peak Code
Domain Error - - - 15 dBm/3.84MHz
Open Loop
Output Power
Ior =-106.7dBm/3.84MHz -46.7 - -28.7 dBm/3.84MHz
Ior =-65.7dBm/3.84MHz -23.0 - -5.0 dBm/3.84MHz
Ior =-25.0dBm/3.84MHz -0.0 - 14.0 dBm/3.84MHz
Transmit Off
Power - - - -56 dBm/3.84MHz
Spectrum
Emission Mask
Δf = 2.5~3.5MHz -35-15 * (Δf-2.5) dBc/30KHz
Δf = 3.5~7.5MHz -35-1 * (Δf-3.5) dBc/1MHz
Δf = 7.5~8.5MHz -39 10 * (Δf-7.5) dBc/1MHz
Δf = 8.5~12.5MHz -49 dBc/1MHz

2. PERFORMANCE
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Only for training and service purposes
LGE Internal Use Only
LG-D685 Product SPEC
8
Transmit Spurious
Emission
9kHz ~ 150kHz -36 dBm
150kHz ~ 30MHz -36 dBm
30MHz ~ 1GHz -36 dBm
1GHz ~ 12.5GHz -30 dBm

2. PERFORMANCE
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Only for training and service purposes
LGE Internal Use Only
LG-D685 Product SPEC
9
2) WCDMA receiver specification
Item Specification
Receive Frequency
FDD1: 2110 ~ 2170 MHz
FDD2: 1930 ~ 1990 MHz
FDD5: 869 MHz ~ 894 MHz
FDD8: 925 MHz ~ 960 MHz
Reference Sensitivity Level
<REFÎor>
FDD1 : BER < 0.001 when Îor = -106.7 dBm / 3.84 MHz
FDD2 : BER < 0.001 when Îor = -104.7 dBm / 3.84 MHz
FDD5 : BER < 0.001 when Îor = -104.7 dBm / 3.84 MHz
FDD8 : BER < 0.001 when Îor = -103.7 dBm / 3.84 MHz
Maximum Input Level BER < 0.001 when Îor = -25 dBm / 3.84 MHz
Adjacent Channel Selectivity
(ACS)
ACS > 33 dB where BER < 0.001 when
Îor = <REFÎor> + 14 dB / 3.84 MHz
& Ioac = –52 dBm / 3.84 MHz @ ±5 MHz
Blocking Characteristic
BER < 0.001 when Îor = <REFÎor> + 3 dB / 3.84 MHz
& Iblocking = -56 dBm / 3.84 MHz @ Fuw(offset) = ±10 MHz
or Iblocking = -44 dBm / 3.84 MHz @ Fuw(offset) = ±15 MHz
Spurious Response BER < 0.001 when Îor = <REFÎor> + 3 dB / 3.84 MHz
& Iblocking = -44 dBm
Intermodulation
BER < 0.001 when Îor= <REFÎor> + 3 dB / 3.84 MHz
& Iouw1 = -46 dBm @ Fuw1(offset) = ±10 MHz
& Iouw2 = -46 dBm / 3.84 MHz @ Fuw2(offset) = ±20 MHz
Spurious Emissions < -57 dBm / 100 kHz BW @ 9 kHz ≤ f < 1 GHz
< -47 dBm / 1 MHz BW @ 1 GHz ≤ f ≤ 12.75 GHz
Inner Loop Power Control
In Uplink
Adjust output(TPC command)
cmd 1dB 2dB 3dB
+1 +0.5/1.5 +1/3 +1.5/4
0 -0.5/+0.5 -0.5/+0.5 -0.5/+0.5
-1 -0.5/-1.5 -1/-3 -1.5/-4
group(10equal command group)
+1 +8/+12 +16/+24
2) WCDMA receiver specication