LG MG150 User manual

Service Manual Model : MG150
Date: August, 2005 / Issue 1.0
Service Manual
MG150

The information in this manual is subject to change without notice and should not be construed as a
commitment by LGE Inc. Furthermore, LGE Inc. reserves the right, without notice, to make changes to
equipment design as advances in engineering and manufacturing methods warrant.
This manual provides the information necessary to install, program, operate and maintain the MG150.
REVISED HISTORY
DATE ISSUE CONTENTS OF CHANGES S/W VERSION
01/JUL/2005 ISSUE 1.0 Initial Release

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1. Introduction ..................................... 5
1.1 Purpose................................................... 5
1.2 Regulatory Information............................ 5
2. General Performance...................... 9
2.1 Product Name ......................................... 9
2.2 Supporting Standard............................... 9
2.3 Main Parts............................................... 9
2.4 H/W Features........................................ 10
2.5 S/W Features ........................................ 12
3. H/W Circuit Description................ 14
3.1. General Description ............................. 14
3.2. Receiver Part ....................................... 14
3.3. Transmitter Part ................................... 17
3.4. Digital Baseband (DBB) Processor...... 21
3.5. Analog Baseband (ABB) Processor..... 26
4. TROUBLE SHOOTING .................. 45
4.1. Main Components Placement.............. 45
4.2. FPCB Components Placement ............ 46
4.3. Baseband Components ....................... 46
4.4 Main Components (Description) ........... 47
4.5. Power On Trouble................................ 48
4.6. Charging Trouble ................................. 49
4.7. LCD Display Trouble............................ 51
4.8. Receiver Trouble.................................. 53
4.9. Microphone Trouble ............................. 57
4.10. Vibrator Trouble ................................. 59
4.11. Keypad Backlight Trouble.................. 60
4.12 FOLDER Open/Close Trouble ............ 62
4.13. SIM Detect Trouble ............................ 64
4.14. Earphone Trouble .............................. 66
5. DOWNLOAD .................................. 85
5.1. Download Setup................................... 85
5.2. Download Procedure ........................... 86
6. SERVICE AND CALIBRATION...... 93
6.1. Service S/W ......................................... 93
6.2. Calibration............................................ 96
7. BLOCK DIAGRAM ....................... 100
8. CIRCUIT DIAGRAM ..................... 103
9. PCB LAYOUT ............................... 107
10. ENGINEERING MODE ............... 109
11. STANDALONE TEST ................. 110
11.1 Setting Method.................................. 110
Table of Contents

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12. EXPLODED VIEW &
REPLACEMENT PART LIST...... 111
12.1 EXPLODED VIEW ............................ 111
12.2 Replacement Parts ........................... 113
<Mechanic component>.................... 113
<Main component> ........................... 116
12.3 Accessory ......................................... 126

1. Introduction
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1.1. Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of the MG150.
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 you’re 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. LGE 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. LGE 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 MG150 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 the MG150 must be performed only by the LGE 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
- 6 -
E. Notice of Radiated Emissions
The MG150 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
An MG150 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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APC Automatic Power Control
BB Baseband
BER Bit Error Ratio
CC-CV Constant Current - Constant Voltage
DAC Digital to Analog Converter
DCS Digital Communication System
dBm dB relative to 1 milliwatt
DSP Digital Signal Processing
EEPROM Electrical Erasable Programmable Read-Only Memory
EL Electoluminescence
ESD Electroluminesc Electrostatic Discharge
FPCB Flexible Printed Circuit Board
GMSK Gaussian Minimum Shift Keying
GPIB General Purpose Interface Bus
GSM Global System for Mobile Communications
IPUI International Portable User Identity
IF Intermediate Frequency
LCD Liquid Crystal Display
LDO Low Drop Output
LED Light Emitting Diode
OPLL Offset Phase Locked Loop
PAM Power Amplifier Module
PCB Printed Circuit Board
PGA Programmable Gain Amplifier
PLL Phase Locked Loop
PSTN Public Switched Telephone Network
RF Radio Frequency
RLR Receiving Loudness Rating
RMS Root Mean Square

1. Introduction
- 8 -
RTC Real Time Clock
SAW Surface Acoustic Wave
SIM Subscriber Identity Module
SLR Sending Loudness Rating
SRAM Static Random Access Memory
STMR Side Tone Masking Rating
TA Travel Adapter
TDD Time Division Duplex
TDMA Time Division Multiple Access
UART Universal Asynchronous Receiver/Transmitter
VCO Voltage Controlled Oscillator
DCXO Digitally Control Crystal Oscillator
WAP Wireless Application Protocol

2. General Performance
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2.1 Product Name
MG150: Support GPRS (Class 10)
2.2 Supporting Standard
2.3 Main Parts: GSM Solution
2. General Performance
Item Feature Comment
GSM850/PCS1900/DCS1800
Supporting Standard with seamless handover
Phase 2+(include AMR)
SIM Toolkit : Class 1,2,3,A~E
GSM850 TX : 824 - 849 MHz
GSM850 RX : 869 - 894 MHz
Frequency Range PCS1900 TX : 1850 - 1910 MHz
PCS1900 RX : 1930 - 1990 MHz
DCS1800 TX : 1710-1785 MHz
DCS1800 RX : 1805-1880 MHz
Application Standard
WAP .2.0
JAVA 2.0
MMS
IM : WV1.1
Digital Baseband Calypso-AMR C035(D751992GHH)
Analog Baseband IOTA(TWL3025)
RF Chip Aero I+/Si4206

2.4 H/W Features
2. General Performance
- 10 -
Item Feature Comment
Form Factor Dual LCD Folder
1) Capacity Standard : Size: 34.15 53.55 5.7 mm
Battery Li-ion, 830mAh, Weight: 30g
2) Packing Type : Hard Pack
Size Standard : 88 ×46 ×24.3
Weight 96.5 gram
Volume 82.8cc
PCB One PCB:8 Layers , 1t
Stand by time 220 hours Paging Period:9, RSSI: -85dBm
Charging time 3 hr.
Talk time 2.5hours
RX sensitivity GSM 850 : -105 dBm
PCS/DCS : -105 dBm
TX output power GSM 850 : 32 dBm Class4 (GSM)
PCS /DCS : 29.5 dBm Class1 (PCS/DCS)
GPRS compatibility GPRS Class 10
SIM card type Plug-In SIM 3V
Main LCD
128*128, 65K Color CSTN
Display Sub LCD
96*64, Color Filter
Backlight : White LED
Built-in Camera N.A.

2. General Performance
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Status Indicator No
Keypad Alpha/numeric Key : 10
Function Key : 14
Side Key : 2
Total # of Keys : 26
ANT Fixed Type
System connector 24 Pin
Ear Phone Jack 3 Pole (2.5mm)
PC synchronization Yes
Memory Flash : 128Mbit
SRAM : 64Mbit
Speech coding FR, EFR, HR,AMR
Data & Fax Built in Data & Fax support
Vibrator Built in Vibrator
IrDA NO
MIDI(for Buzzer Function) YAMAHA 40 Poly Buzzer Function By Using
Speaker Phone & MIDI IC
Voice Recording YES
Speaker Phone YES
Travel Adapter Yes
CDROM TBD
Options Ear-Microphone
Data Cable
Cigarette Lighter Adapter
Data Cable

2.5 S/W Features
2. General Performance
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Item Feature Comment
RSSI 0 ~ 5 Levels
Battery Charging 0 ~ 4 Levels
Key Volume 0 ~ 5 Level
Audio Volume 1 ~ 5 Level
Time / Date Display Yes NITZ
Multi- Language Yes English / Spanish / France
Quick Access Mode Phone Book / Web Access/
Sound / Message / IM /
Speed Dial Yes
CLIP / CLIR Yes (different melody)
Phone Book 3 Numbers + 1 Memo + 1 e-mail- Total 255 Member
+ Group Select + Picture
Last Dial Number Yes
Last Received Number Yes
Last Missed Number Yes
Search by Number/ Name Name only
Group 7
Fixed Dial Number Yes
Service Dial Number Yes
Own Number Yes
Voice Memo Yes
Call Reminder Yes
Network Selection Automatic / Manual
Mute Yes
Call Divert Yes
Call Barring Yes
Call Charge (AoC) Yes
Call Duration Yes
SMS (EMS) 100 EMS : Release4
(Except Text align)
E- Mail Yes Over SMS
SMS Over GPRS Yes

2. General Performance
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Game 1 Java Game
Calendar Yes
Memo 20
World Clock Yes
Unit Convert Length/Surface/Volume/Weight
Fax & Data Yes
Wall Paper Yes Default 4ea
WAP Browser WAP 2. 0 Openwave 6.2
Download Melody / Yes Over WAP
Wallpaper
SIM Lock Yes Operator Dependent
SIM Toolkit Class 1, 2, 3, A - E
MMS Yes Openwave MMS Client
EONS Yes
CPHS Yes V4.2
Camera NO
JAVA Yes CLDC V1. 1 / MIDP V 2.0
Download Over WAP
Voice Dial Yes 10
IrDA No
GPRS Yes Class10
Hold / Retrieve Yes
Conference Call Yes Max. 6
DTMF Yes
Memo pad Yes
TTY No
AMR Yes

3.1 General Description
The RF part consists of a transmitter, a receiver, a synthesizer, a voltage supply and a DCXO part.
And the main RF Chipset Aero I+ is a single-chip triple-band transceiver for the extended global
system for mobile communication [GSM850MHz] /Digital communication system [PCS1900MHz] voice
and data transfer applications. The Aero I+ includes a digitally-controlled crystal oscillator(DCXO)
function and completely integrates the reference oscillator and varactor
3.2 Receiver Part
The Receiver part in Aero I+ contains all active circuits completely, full receiver chain with the
exception of discrete front-end RF SAW filters. The filtered and amplified signal is down converted in
the RF-mixer to the base-band output. The receive path is supported by internal channel filtering.
3. H/W Circuit Description
3. H/W Circuit Description
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Figure 1. RF Receiver Block

3. H/W Circuit Description
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3.2.1. RF Front End
Antenna switch and dual saw filters are integrated in FEM (F400). The Received RF signals (GSM
869MHz ~ 894MHz, PCS 1930MHz ~ 1990MHz), DCS(1710MHz ~ 1880 MHz) are fed into the
antenna and Mobile switch. An antenna matching circuit is between the antenna and the mobile
switch.
The Antenna Switch in FEM (F400) is used to control the Rx and Tx paths. And, the input signals VC1,
VC2 and VC3 of FEM are directly connected to base-band controller to switch either Tx or Rx path on.
FEM (F400) supports for dual FEM control logics given below Table 3.1 The receiver part uses a LOW
IF conversion receiver architecture that allows for the on-chip integration.
The Aero I+ integrates dual differential input LNAs that are matched to the 150 ohm in GSM850 and
150 ohm in PCS balanced-output FEM through external LC matching networks.
3.2.2. Demodulator and Baseband Processing
In LOW IF receiver there is only one mixer down-converting received RF signal to BB signal directly.
Aero I+ has 4 Gain steps. Front end and VGA high gain mode is 66dB, Front-end intermediate Gain
and VGA high gain mode is 60dB, Front-end low gain and VGA high gain mode is 46dB, Front-end
and VGA low gain mode is 20dB. The Rx gain setting is done in the AGC algorithm.
The nominal gain of the receiver is set as a function of the expected signal strength at the antenna
input so that a desired level is reached at the Rx I/Q. The receiver chain in Aero I+ has variable gain
parts, LNA, Mixer, LPF, VGA, VGA Filter, Auxiliary gain control and VGA. The gain settings can be
adjustable via 3-wire bus control lines. The base-band signals pass via integrated low-pass filters to
the base-band A/D converters. The remainder of the channel filtering is performed by the baseband
chipset. The demodulator contains switches to maintain the sense of the baseband I/Q outputs with
respect to the incoming RF signal on GSM850 and PCS1900.
Table 3-1. The Logic and Current
Switch Mode SW1 SW2 SW3
GSM850 Tx H L L
PCS1900 Tx L H H
GSM850 Rx L L L
PCS1900 Rx L L H
DCS1800 Rx L L L

3. H/W Circuit Description
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3.2.3. Synthesizer
The RF main chipset includes a fully integrated VCO with an on-chip LC tank. A fractional-N
synthesizer can phase lock the local oscillator used in both transmit and receive path to a precision
frequency reference input. The fractional-N operation offers low phase noise and fast setting times,
allowing for multiple slot applications such as GPRS. The counter and mode settings of the
synthesizer are also programmed via 3-wire interface.
Fig 2. Block diagram of Synthesizer Part

3. H/W Circuit Description
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3.3 Transmitter Part
The transmit (TX) section consists of an I/Q baseband upconverter, an offset phase-locked loop
(OPLL), and two 50 output buffers that can drive external power amplifiers (PA), one for the GSM 850
(824-849 MHz) and E-GSM 900 (880-915 MHz) bands and one for the DCS 1800 (1710-1785 MHz)
and PCS 1900 (1850-1910 MHz) bands. The OPLL requires no external duplexer to attenuate
transmitter noise and spurious signals in the receive band, saving both cost and power.
Additionally, the output of the transmit VCO (TXVCO) is a constant-envelope signal that reduces the
problem of spectral spreading caused by non-linearity in the PA.
A quadrature mixer upconverts the differential in-phase(BIP, BIN) and quadrature (BQP, BQN) signals
with the IFLO to generate a SSB IF signal that is filtered and used as the reference input to the OPLL.
The IFLO frequency is generated between 766 and 896 MHz. The IFLO is divided by two to generate
the quadrature LO signals for the quadrature modulator, resulting in an IF between 383 and 448 MHz.
For the E-GSM 900 band, two different IFLO frequencies are required for spur management.
The OPLL consists of a feedback mixer, a phase detector, a loop filter, and a fully integrated TXVCO.
The TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its output is divided by two
for the GSM 850 and E-GSM 900 bands.
The Si4133T generates the RFLO frequency between 1272 and 1483 MHz. To allow a single VCO to
be used for the RFLO, high-side injection is used for the GSM 850 and E-GSM 900 bands, and
lowside injection is used for the DCS 1800 and PCS 1900 bands.
3.3.1. Digital low IF
The receive section uses a digital low IF architecture that avoids the difficulties associated with direct
conversion while delivering lower solution cost and reduced complexity. The baseband interface is
compatible with any supplier’s baseband subsystem.The transmit section is a complete up-conversion
path from the baseband subsystem to the power amplifier,and sude an offset phase-locked loop(PLL)
with a fully integrated transmit VCO.The frequency systhesizer uses
Fig 3. Transmitter Block diagram

3. H/W Circuit Description
- 18 -
3.3.2. PLL
The OPLL consists of a feedback mixer, a phase detector, a loop filter, and a fully integrated TXVCO.
The TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its output is divided by 2
for the GSM 850 and E-GSM 900 bands. The RFLO frequency is generated between 1272 and 1483
MHz. To allow a single VCO to be used for the RFLO, high-side injection is used for the GSM 850 and
E-GSM 900 bands, and low-side injection is used for the DCS 1800 and PCS 1900 bands. Low-pass
filters before the OPLL phase detector reduce the harmonic content of the quadrature modulator and
feedback mixer outputs. The cutoff frequency of the filters is programmable with the FIF[3:0] bits in
register 04h. The OPLL requires no external duplexer to attenuate transmitter noise and spurious
signals in the receive band. Additionally, the output of the transmit VCO (TXVCO) is a constant-
envelope signal which reduces the problem of spectral spreading caused by non-linearity in the PA.
Fig 4. Block diagram of IF Modulator
Fig 5. Block diagram of PLL

3. H/W Circuit Description
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3.3.3 Power Amplifier
The Power Amplifier Module [SKY77325, U406] is a dual-band GSM/PCS power amplifier module that
incorporates an indirect closed loop method of power control. The indirect closed loop is fully self-
contained and it does not require loop optimization. It can be driven directly from the DAC output in the
baseband circuit. On-board power control provides over 37 dB of control range with an analog voltage
input [VAPC]. Efficiency is about 49% at GSM850 and about 53% at PCS.
5dB Atten.
6dB Atten.
PAM
VBAT
150
R403
13
GND6 14
16
GND7 GND8 18 GND9 21
GSM_IN 612 GSM_OUT
NC
1
PAC_ENABLE 2
23
PGND
RSVD
15
22 VAPC 20 VBATT
3VCC1A
VCC1B
8
VSENSE
19
SKY77325
BS 4
DCS_PCS_IN 5 DCS_PCS_OUT
17
7
GND1 GND2 9 GND3 10 GND4 11 GND5
0.01u
U406
C412
C491 1.2p
L410 10nH
0R406
2.7nHL400
L403 3.9nH
C419 33p
0.75p
C402
R407
NA
C407
0.75p
C418 12p
33uC420
C403
22nH
C413 0.01u
C406
2p
39R402
39p
C409
0.01uC414
APC
Fig 7. Schematic of PAM circuit
Fig 6. Internal Functional Block diagram