LG LG-L25 User manual

Internal Use Only
Service Manual
LG-L25
Date: Dec, 2014 / Issue 0.9

- 2 - Copyright © 2014 LG Electronics. Inc. All right reserved.
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 Functions of Major Semi-Conductors..............................................5
2.4 HW Features ...............................................................................................6
2.5 SW Features ................................................................................................7
2.6 H/W SPEC.................................................................................................. 10
3. TROUBLE SHOOTING .......................................................... 11
3.1 RF Components ..................................................................................... 11
3.2 LTE & WCDMA & CDMA & GSM Tx SIGNAL PATH ...................... 14
3.3 LTE & WCDMA & CDMA & GSM Rx SIGNAL PATH...................... 15
3.4 Checking RF Tx Level............................................................................ 17
3.5 Checking RF Tx Level (Cont.)............................................................. 25
3.6 Checking RF PRx Level ........................................................................ 28
3.7 Checking RF DRx Level........................................................................ 31
3.8 GPS/WIFI/BT Module............................................................................ 34
3.9 GPS/WIFI/BT SIGNAL PATH ................................................................ 36
3.10 Checking GPS/WIFI/BT...................................................................... 37
3.11 Checking NFC....................................................................................... 43
3. 12 SIM........................................................................................................... 46
3. 13 Side Key ................................................................................................. 48
3. 14 USB .......................................................................................................... 50
3. 15 Gyro Sensor / Accelerometer sensor ......................................... 53
3. 16 Compass Sensor................................................................................. 56
3. 17 Proximity/Ambient Light Sensor................................................. 59
3. 18 Camera................................................................................................... 62
3. 19 LCD .......................................................................................................... 68
3. 20 Touch Trouble Shooting.................................................................. 71
3. 21 Vibrator Troubleshooting ............................................................... 74
3. 22 Audio ...................................................................................................... 76
4. DOWNLOAD......................................................................... 86
5. BLOCK DIAGRAM..............................................................102
6. CIRCUIT DIAGRAM ............................................................111
7. BGA PIN MAP.....................................................................127
8. PCB LAYOUT.......................................................................142
9. CALIBRATION.....................................................................148
10. HIDDEN MENU.................................................................167
11. DISASSEMBLE GUIDE......................................................172
12. EXPLODED VIEW & REPLACEMENT PART LIST .............178

- 3 - Copyright © 2014 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
1. INTRODUCTION
LGE Internal Use Only
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.

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Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
LGE Internal Use Only
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
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.

2. PERFORMANCE
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Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
2.1 Product Name
LGL25 : US Cellula,IMT-2000(EVDO Rev_0&A) /LTE B1,B3,B11,B26 / WCDMA B1,B5 / GPS
2.2 Supporting Standard
2.3 Functions of Major Semi-Conductors
LGL25 Product SPEC
5
Classification Function
MSM8926 Digital Baseband Processor
WTR1625L 4G MODEM
PMIC PM8926 PMIC
K4E2E304EE-AGCE Mobile SDRAM(LPDDR3)
WCN3660A BT/WLAN Tranceiver
LGL25 Product SPEC
4
Item Feature Comment
Supporting Standard
US Cellular,IMT-2000 /GPS
LTE B1, B3, B11, B26
WCDMA B1,B5
Frequency Range
US Cellular TX : 816 ~ 848.19 MHz
US Cellular RX : 861~893.19 MHz
IMT-2000 TX : 1920~1979.95 MHz
IMT-2000 RX : 2110~2169.95 MHz
LTEB1 TX : 1920~1979.9 MHz
LTE B1 RX : 2110~2169.9 MHz
LTE B3 TX : 1710~1784.9 MHz
LTE B3 RX : 1805~1879.9 MHz
LTE B11 TX : 1427.9~1447.8 MHz
LTE B11 RX : 1475.9~1495.8 MHz
LTE B26 TX : 814~849 MHz
LTE B26 RX : 859~894 MHz
WCDMA B1 TX : 1920~1979.9MHz
WCDMA B1 RX : 2110~2169.9MHz
WCDMA B5 TX : 826.5~846.6MHz
WCDMA B5 RX : 871.5~891.6MHz
GPS : 1575.42 MHz

2. PERFORMANCE
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LGE Internal Use Only
2.4 HW Features
LGL25 Product SPEC
6
Item Feature Comment
Form Factor DOP
Battery
1) Capacity
Standard : Li-Polymer, 2370mAh Form Factor
2) Packing Type : Hard Pack
Size Standard : 139.0 X 70.0 X 10.5
Weight 148g(Battery)
LCD 4.7”, HD, 1280x720 Pixels,
16.7M Colors, TFT
Built-in Camera 8MP OIS + 2.1MP VT
Keypad Full Touch Screen
Home Key
Side Key :
Power On,
Volume up/down
ANT Main : PIFA(Embeded)Type
System connector u-USB
Ear Phone Jack 3.5Φ Ear Jack
Memory 12Gb(SDRAM LPDDR3)
+ 16GB eMMC
Speech coding QCELP, EVRC, EVRC-B, EVRC-WB,
Vibrator Coin Type
Blue Tooth Bluetooth 3.0
MIDI
(for BuzzerFunction) No
Music Player PCM, MP3, AAC-LC, AAC+, eAAC+, Vorbis,
OGG, AMR(NB/WB), EVRC, QCELP
Video Player MPEG4, H.263, H.264, VP8, Theora
Camcorder
H.264 BP/MP/HP
MPEG-4 SP/ASP
H.263 P0
Voice Recording No
Speaker Phone mode
Support Yes
Travel Adapter No
CDROM No
Stereo Headset No
Data Cable No
T-Flash
(External Memory) No

2. PERFORMANCE
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LGE Internal Use Only
2.5 SW Features
LGL25 Product SPEC
7
Item Feature Comment
RSSI 0 ~ 4 Levels
Battery Charging 0 ~ 10 Levels
Key Volume 0 ~ 15 Level Depends on the active keyboard.
This is a keyboard specific setting.
Audio Volume 0 ~ 15 Level
Time / Date Display Yes
Multi-Language Yes English (US)
日本語
Quick Access Mode No
PC Sync No
Speed Dial Yes Voice mail center -> 1 key
Profile Yes not same with feature phone
setting
CLIP / CLIR Yes/Yes
Phone Book
Name / Phone / Email / Postal
Addresses / Organizations / Birthday
/ Notes
It is possible to save 200 call logs.
Share count last dial number, last
received number, last missed
number
Last Dial Number Yes
It is possible to save 200 call logs.
Share count last dial number, last
received number, last missed
number
Last Received
Number Yes
It is possible to save 200 call logs.
Share count last dial number, last
received number, last missed
number
Last Missed Number Yes
There is no limitation on the
number of items. It depends on
available memory amount
Search by Number
/ Name Number and Name Search by number and name is
supported in Contacts app
Group No
Fixed Dial Number No
Service Dial Number No
Own Number Yes Read only (add/edit/delete are not
supported)

2. PERFORMANCE
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LGE Internal Use Only
LGL25 Product SPEC
8
Item Feature Comment
Voice Memo No
Call Reminder No Support only missed call
notification
Network Selection Automatic Auto, Home only, Roaming only
Mute Yes
Sound Profile support Sound /
Vibrate / Silent. Call mute is
supported
Call Divert Yes
Call Barring No Support only GSM
Call Charge (AoC) No
Call Duration Yes Not support it in menu.
User can find it in call screen
SMS (EMS)
There is no limitation on the number
of items.It depends on available
memory amount.
EMS does not support.
SMS Over GPRS Yes
EMS Melody / Picture No
Send / Receive / Save Yes
MMS MPEG4
Send / Receive / Save Yes
Long Message No
Cell Broadcast No
Download Yes
Game No
No preinstalled game apps.
If user connect to network, access
game web page in Game folder.
Calendar Yes
Memo No
World Clock No
Unit Convert No
Stop Watch Yes
Wall Paper Yes
WAP Browser No WAP stack and wml are not
supported.

2. PERFORMANCE
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LGE Internal Use Only
LGL25 Product SPEC
9
Item Feature Comment
Download Melody /
Wallpaper Yes Over web browser
SIM Lock Yes Operator Dependent
SIM Toolkit Class 1, 2, 3, C, D
MMS Yes
Camera Yes
8M OIS AF
Continuous AF, Face Tracking
focus, Touch Focus, Self Timer,
Image(8M)/Video
Size(1080P) ,HDR, Continuous
Shot, White Balance, ISO,
Brightness, Grid View, Auto Flash
For video, Zoom , Frame Grid,
Volume Key Image capture, Dual
Mode, Indicator, Low Battery
scenario
JAVA No
Voice Dial No
IrDa No
Bluetooth Yes Bluetooth Ver. 3.0
FM radio No
GPRS Yes Class 12
EDGE Yes Class 12
Hold / Retrieve No / No
Conference Call Yes Max. 3
DTMF Yes
Memo pad Yes
TTY Yes
AMR Yes
SyncML No
IM Yes Hangout
Email Yes

2. PERFORMANCE
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LGE Internal Use Only
LGL25 Product SPEC
10
Battery Bar Specification Icon Note
Bar 10(Full) 100%
Bar 10 -> Bar 9 100% -> 99%
Bar 9 -> Bar 8 90% -> 89%
Bar 8 -> Bar 7 80% -> 79%
Bar 7 -> Bar 6 70% -> 69%
Bar 6 -> Bar 5 60% -> 59%
Bar 5 -> Bar 4 50% -> 49%
Bar 4 -> Bar 3 40% -> 39%
Bar 3 -> Bar 2 30% -> 29%
Bar 2 -> Bar 1 16% -> 15%
Bar 1 -> Bar 0 6% -> 5%
Low Battery Pop-up
16% -> 15%
6% -> 5%
Power Off 1% -> 0% 3.4V ~ 3.5V
2.6 Battery Bar

3. TROUBLE SHOOTING
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LGE Internal Use Only
3. TROUBLE SHOOTING
3.1 RF Components
1. TOP side
U1500
RF Transceiver
U1300
B1/B3/B26
BC0/BC6
QSM Quad
PAM
U1102
B11
Single PA
FL1109
B11 Tx SAW
U1400
DCDC
Convertor
U1101
B1/B3/B11/B26
BC0/BC6
GSM Quad
FEMid
FL1105
GSM900
PRx Filter
FL1102
B26/BC0/GSM900
Duplexer
FL1101
B3
Duplexer
FL1104
B1/BC6
Duplexer FL1108
B11
Duplexer FL1115
B3/B26/BC0
Diplexer
FL1112
B26/BC0
DRx Filter
FL1110
B1/BC6
DRx Filter
FL1113
B11
DRx Filter
FL1114
B3
DRx Filter

3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
2. BOTTOM side
SW1103
GPS
B1/B11/BC6
DRX
RF Switch
SW1104
B3/B26/BC0
DRx
RF Switch
SW1101
B1/B3/B26
BC0/BC6
GSM Quad
TRx
RF Switch
SW1102
B11
TRx
RF Switch
FL1111
B1/B11/BC6
DRx
Switch
U1103
GPS LNA
B1/B11
Diplexer FL1106
GPS LNA
B1/B11/BC6
Diplexer
ANT1109 ANT1107
ANT1101
ANT1104
ANT6913
ANT6912
FL1103
B1/B3/B26
BC0/BC6
GSM Quad
Coupler FL1107
B11
Coupler
ANT1102
ANT1105
ANT1103
ANT1106

3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
3. RF components
Reference Description
FL1101 B3 Duplexer
FL1102 B26/BC0/GSM900 Duplexer
FL1103 B1/B3/B26/BC0/BC6/GSM Quad Coupler
FL1104 B1/BC6 Duplexer
FL1105 GSM900 PRx Filter
FL1106 GPS LNA & B1/B11/BC6 Diplexer
FL1107 B11 Coupler
FL1108 B11 Duplexer
FL1109 B11 Tx SAW
FL1110 B1/BC6 DRx Filter
FL1111 B1/B11/BC6 DRx Switch
FL1112 B26/BC0 DRx Filter
FL1113 B11 DRx Filter
FL1114 B3 DRx Filter
FL1115 B3/B26/BC0 Diplexer
U1101 B1/B3/B11/B26/BC0/BC6/GSM Quad FEMid
U1102 B11 Single PA
U1103 GPS LNA & B1/B11 Diplexer
U1300 B1/B3/B26/BC0/BC6/QSM Quad PAM
U1400 DCDC Convertor for PA
U1500 RF Transceiver
SW1101 B1/B3/B26/BC0/BC6/GSM Quad TRx RF Switch
SW1102 B11 TRx RF Switch
SW1103 GPS & B1/B11/BC6 DRX RF Switch
SW1104 B3/B26/BC0 DRx RF Switch
ANT1101/1104 B11 Main Ant Contact
ANT1107/1109 B1/B3/B26/BC0/BC6/GSM Quad Main Ant Contact
ANT1102/1103 GPS & B1/B11/BC6 Sub Ant Contact
ANT1105/1106 B3/B26/BC0 Sub Ant Contact

3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
3.2 LTE & WCDMA & CDMA & GSM Tx SIGNAL PATH
B3
B26(WB5)/BC0
B11
GSM 850/900
GSM1800/1900
B1(WB1)/BC6
B1(WB1)/B3/B26(WB5)/BC0/BC6/GSM Quad Common

3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
3.3 LTE & WCDMA & CDMA & GSM Rx SIGNAL PATH
B3
B26(WB5)/BC0/GSM850
B11
GSM 900
GSM1800/1900
B1(WB1)/BC6
B1(WB1)/B3/B26(WB5)/BC0/BC6/GSM Quad PRx Common
B11 DRx
B1(WB1)/BC6 DRx
B26(WB5)/BC0 DRx
B3 DRx

3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
Checking LTE & WCDMA & CDMA & GSM Block
START
1. Check
DC POWER Supply Circuit
3. Check RF Signal Path
2. Check XO
Re-Download S/W & Cal

3. TROUBLE SHOOTING
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Only for training and service purposes
LGE Internal Use Only
3.4 Checking RF Tx Level
(LTE B1/B3/B11/B26 & WCDMA B1/B5 & CDMA BC0/BC6 & GSM Quad)
TP2 TP1
U1300
B1(WB1)/B3/B26(WB5)
BC0/BC6
QSM Quad
PAM
TP3TP4
TP5
TP11
TP12
TP15
TP14
TP6 U1102
B11
Single
PA TP16
TP21
TP22 TP23
TP24
TP25
TP26

3. TROUBLE SHOOTING
- 18 - Copyright © 2014 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
jXZWW YU^
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sXZWX
2
1
ZZjXZWY
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1
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kup
sXZW_
2
1
ZZ
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1
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ZZsXZW`
1
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RFOUT_GSM_HB
RFIN_B26
RFIN_B5_B8
GND1
VIO
GND13
RFIN_B1_B2
RFIN_GSM_HB
GND7
GND6
RFIN_GSM_LB
VBATT
GND3
SCLK
GND8
RFIN_B4
GND5
GND9 GND11 GND10
GND2
GND4
SDATA
RFOUT_GSM_LB
GND12
RFOUT_B4
RFOUT_B2
RFOUT_B5_B26
GND14
RFOUT_B8
VCC1
VCC2
VCC_GSM
RFOUT_B3
GND15
RFOUT_B1
GND16
NC
GND17 GND18 GND19
GND20
PGND
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kup
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PGND
VCC1VCC2
RFINRFOUT
SDATA
VBATNC
VIOGND
SCLK
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TP1
TP3
TP2
TP4
TP5
TP21
TP22 TP23 TP11
TP12
TP14
TP24
TP6
TP25 TP26
TP16
TP15

3. TROUBLE SHOOTING
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LGE Internal Use Only
3.4.1 Checking RF Tx Level (LTE B1, WCDMA B1, CDMA BC6)
START Set the Phone Tx is ON, Set RGI=90
Change the Board
Check TP1(C1300) at
U1300
Check OVER 21dBm
Check TP21,22,23 at U1300
Check Over
TP21,22 : Over 3.0V
TP23 : Over 1.7V
Check TP11(C1301) at U1300
Check OVER -3dBm
PAM Circuit is OK, See next Page
PM8926 is OK
WTR1625L is OK
YES
YES
YES
NO
NO
NO

3. TROUBLE SHOOTING
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LGE Internal Use Only
3.4.2 Checking RF Tx Level (LTE B3)
START Set the Phone Tx is ON, Set RGI=90
Change the Board
Check TP3(C1303) at
U1300
Check OVER 21dBm
Check TP21,22,23 at U1300
Check Over
TP21,22 : Over 3.0V
TP23 : Over 1.7V
Check TP11(C1301) at U1300
Check OVER -3dBm
PAM Circuit is OK, See next Page
PM8926 is OK
WTR1625L is OK
YES
YES
YES
NO
NO
NO