LG LG-T370 User manual

Internal Use Only
Service Manual
LG-T370
Date: April, 2012 / Issue 1.0

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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Table Of Contents
1. INTRODUCTION...................................................................3
1.1 Purpose .....................................................................................................3
1.2 Regulatory Information......................................................................3
1.3 Abbreviations..........................................................................................5
2. PERFORMANCE....................................................................7
2.1 H/W Features...........................................................................................7
2.2 Technical Specication........................................................................9
3. TECHNICAL BRIEF..............................................................14
3.1 Digital Main Processor...................................................................... 14
3.2 Power Management ......................................................................... 19
3.3 FEM with integrated Power Amplier Module (SKY77550-
21, U101)....................................................................................................... 33
3.4 Crystal(26 MHz, X201) ...................................................................... 35
3.5 RF Subsystem of PMB8815 (U201) .............................................. 36
3.6 MEMORY(H9DA2GH1GHMMMR, U301 ) .................................. 41
3.7 BT module ............................................................................................. 44
3.8 SIM Card Interface.............................................................................. 45
3.9 LCD Interface........................................................................................ 47
3.10 MiniABB (Battery Charger & MUIC) Interface....................... 50
3.11 Audio Interface................................................................................ 51
3.12 Camera Interface(2M Fixed Focus Camera) .......................... 57
3.13 Touch Interface................................................................................. 60
4. TROUBLE SHOOTING ........................................................62
4.1 RF Component .................................................................................... 62
4.2 RX Trouble ............................................................................................. 63
4.3 Power On Trouble............................................................................... 68
4.4 Charging Trouble................................................................................ 70
4.5 Vibrator Trouble .................................................................................. 72
4.6 LCD Trouble .......................................................................................... 75
4.7 Camera Trouble................................................................................... 79
4.8 Speaker / Receiver Trouble............................................................. 83
4.9 Earphone Trouble............................................................................... 85
4.10 Microphone Trouble....................................................................... 88
4.11 SIM Card Interface Trouble........................................................... 90
4.12 Micro SD (uSD) Trouble ................................................................. 92
4.13 Bluetooth Trouble............................................................................ 94
4.14 FM Radio Trouble............................................................................. 96
4.15 Touch trouble .................................................................................... 98
4.16 Memory trouble.............................................................................100
4.17 Proximity Sensor on/o Trouble Shooting..........................104
5. DOWNLOAD.....................................................................106
6. BLOCK DIAGRAM.............................................................119
7. CIRCUIT DIAGRAM ..........................................................120
8. BGA PIN MAP ..................................................................127
9. PCB LAYOUT.....................................................................129
10. ENGINEERING MODE ....................................................131
11. STAND ALONE TEST ......................................................132
11.1 Introduction.....................................................................................132
11.2 Setting Method ..............................................................................132
11.3 Tx Test .................................................................................................134
11.4 Rx Test.................................................................................................134
12.AUTO CALIBRATION.......................................................137
12.1 Overview...........................................................................................137
12.2 Tachyon Directory..........................................................................137
12.3 Test Equipment Setup..................................................................138
12.4 Procedure..........................................................................................138
12.5 AGC......................................................................................................145
12.6 APC ......................................................................................................145
12.7 ADC......................................................................................................145
12.8 Target Power....................................................................................145
13. EXPLODED VIEW & REPLACEMENT PART LIST ..........146
13.1 EXPLODED VIEW.............................................................................146
13.2 Replacement Parts ........................................................................147
13.3 Accessory ..........................................................................................166

1. INTRODUCTION
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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the features of
1. INTRODUCTION
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
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
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
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.
T
h
e
use
r m
ay
n
ot
m
a
k
e
a
n
y
c
h
a
n
ges
a
n
d/o
r r
epa
ir
s
e
x
pect
as
spec
ifi
ca
ll
y
n
oted
in
t
hi
s
m
a
n
ua
l
.
Th
e
r
e
f
o
r
e,
n
ote
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ
e use ay ot a e a y c a ges a d/o epa s e pect as spec ca y oted t s a ua . e e o e, ote
that unauthorized alternations or repair may affect the regulatory status of the system and may void any
remaining warranty.

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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
E. Notice of Radiated Emissions
T
his model com
p
lies with rules re
g
ardin
g
radiation and radio fre
q
uenc
y
emission as defined b
y
local re
g
ulator
y
2. INTRODUCTION
p g g q y y g y
agencies. In accordance with these agencies, you may be required to provide information such as the following to
the end user.
F. Pictures
T
he 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
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.
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ \VX[^
• When returning system boards or parts like EEPROM to the factory, use the protective
package as described.

1. INTRODUCTION
- 5 -
LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1.3 Abbreviations
F th f thi l f ll i bb i ti l
1. INTRODUCTION
F
or
th
e purposes o
f
thi
s manua
l
,
f
o
ll
ow
i
ng a
bb
rev
i
a
ti
ons app
l
y:
Bit Error RatioBER
BasebandBB
Automatic Power ControlAPC
Digital Signal Processing
DSP
dB relative to 1 milli wattdBm
Digital Communication SystemDCS
Digital to Analog ConverterDAC
Constant Current – Constant VoltageCC-CV
Gaussian Minimum Shift Ke
y
in
g
GMS
K
Flexible Printed Circuit BoardFPCB
Electrostatic DischargeESD
Electrical Erasable Programmable Read-Only MemoryEEPROM
Digital
Signal
Processing
DSP
Intermediate Fre
q
uenc
y
IF
International Portable User IdentityIPUI
Global System for Mobile CommunicationsGSM
General Purpose Interface BusGPIB
y g
Off t Ph L k d L
OPLL
Light Emitting DiodeLED
Low Drop OutputLDO
Liquid Crystal DisplayLCD
q y
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ ]VX[^
Off
se
t
Ph
ase
L
oc
k
e
d
L
oop
OPLL

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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
Power Amplifier ModulePAM
1. INTRODUCTION
Public Switched Telephone NetworkPSTN
Phase Locked LoopPLL
Programmable Gain AmplifierPGA
Printed Circuit BoardPCB
Real Time Clock
RTC
Root Mean SquareRMS
Receiving Loudness RatingRLR
Radio FrequencyRF
Sending Loudness RatingSLR
Subscriber Identity ModuleSIM
Surface Acoustic WaveSAW
Real
Time
Clock
RTC
Travel AdapterTA
Side Tone Masking RatingSTMR
Pseudo SRAMPSRAM
Static Random Access MemorySRAM
Voltage Controlled OscillatorVCO
Universal Asynchronous Receiver/TransmitterUART
Time Division Multiple AccessTDMA
T
ime Division Duplex
T
DD
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ ^VX[^
Wireless Application Protocol
WAP
Voltage Control Temperature Compensated Crystal OscillatorVCTCXO

2. PERFORMANCE
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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
2.1 H/W Features
2. SYSTEM SPECIFICATION
Item Feature Comment
Standard Battery Lithium-Ion, 3.7V 950mAh
Stand by TIME Up to 500 hrs : Paging Period 5, RSSI 85dBm
Talk time
Up to 5hrs : GSM Tx Level 7
Talk
time
Up
to
5hrs
:
GSM
Tx
Level
7
Stand by time Up to 500 hours (Paging Period: 5, RSSI: -85 dBm)
Charging time Approx 3hours
RX Sensitivity GSM, EGSM: -109dBm, DCS: -109dBm
GSM EGSM: 32 5dBm(Level 5)
TX output power
GSM
,
EGSM:
32
.
5dBm(Level
5)
,
DCS , PCS: 29.5dBm(Level 0)
SIM card type 3V / 1.8V
Display MAIN : 2.8” TFT 240 Ý320 pixel 262K Color
GPRS compatibility Class 12
Status Indicator Send Key, End Key, Cancel Key,
Volume Up/Down Key, PWR(Lock) Key,
ANT Internal
EAR Phone Jack Yes (3.5Φ)
PC Synchronization Yes
Speech coding EFR/FR/HR
Data and Fax Yes
Vibrator Yes
Loud Speaker Yes
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ _VX[^
Voice Recoding Yes
Microphone Yes

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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
2. SYSTEM SPECIFICATION
S k /R i
18 12Φ S k /
R i
Item Feature Comment
Travel Adapter Yes
S
pea
k
er
/R
ece
i
ver
18
x
12Φ
S
pea
k
er
/
R
ece
i
ver
MIDI SW MIDI (Mono SPK)
Camera 2.0M FF
Bluetooth / FM Radio Bluetooth version 2.1 / Wired FM radio (Earphone needed)
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ `VX[^

2. PERFORMANCE
- 9 -
LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2.2 Technical Specification
Item Description Specification
2. SYSTEM 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
T
X: 1850 ~ 1910 MHz
RX: 1930 ~ 1990 MHz
2 Phase Error RMS < 5 degrees
Peak < 20 degrees
3 Frequency Error < 0.1 ppm
Level Power Toler. Level Power Toler.
GSM850/EGSM
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
5 33dBm ·2dB 13 17dBm ·3dB
4 Power Level
10 23dBm ·3dB 18 7dBm ·5dB
11 21dBm ·3dB 19 5dBm ·5dB
12 19dBm ·3dB
Level Power Toler. Level Power Toler.
DCS/PCS
1 28dBm ·3dB 9 12dBm ·4dB
2 26dBm ·3dB 10 10dBm ·4dB
3 24dBm ·3dB 11 8dBm ·4dB
4 22dBm ·3dB 12 6dBm ·4dB
0 30dBm ·2dB 8 14dBm ·3dB
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ XWVX[^
5 20dBm ·3dB 13 4dBm ·4dB
6 18dBm ·3dB 14 2dBm ·5dB
7 16dBm ·3dB 15 0dBm ·5dB

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LGE Internal Use Only Copyright © 2012 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
Item Description Specification
2. SYSTEM SPECIFICATION
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
GSM850/ EGSM
400 -60
600~ <1,200 -60
1,200~ <1,800 -60
1,800~ <3,000 -63
3,000~ <6,000 -65
6 000
71
5Output RF Spectrum
(due to modulation)
6
,
000
-
71
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
DCS/PCS
250 -33
400 -60
600~ <1,200 -60
1,200~ <1,800 -60
1,800~ <3,000 -65
3,000
~
<6,000
-
65
3,000
<6,000
65
6,000 -73
6
Output RF Spectrum
(due to switching
transient)
GSM850/ EGSM
Offset from Carrier (kHz). Max. dBm
400 -19
600
21
ͽ͸ͶͺΟΥΖΣΟΒΝΆΤΖ΀ΟΝΪ XXVX[^
transient)
600
-
21
1,200 -21
1,800 -24