LG MG120a User manual

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Table of Contents
1. INTRODUCTION……………………………………………………………………………..P5
2. PERFORMANCE………………………………………………………………………….....P9
2.1 H/W Features…………………………………………………………………………......................P8
2.2 Technical Specification………………………………………………………………………….....P9
3. TECHNICAL BRIEF………………………………………………………….………….P15
3.1 MG120 Block Diagram………………………………………………………………………….....P15
3.2 RF Part Introductions………………………………………………………………………..........P16
3.3 Baseband Introductions……………………………………………………………………….….P21
4. TROUBLE SHOOTING………………………………………………….……………P33
4.1 RF Components…………………………………………………………………..…….................P34
4.2 RX Trouble………………………………………………………………………............................P35
4.3 TX Trouble………………………………………………………………………............................P41
4.4 Power On Trouble…………………………………………………………………………............P48
4.5 Charging Trouble………………………………………………………………………………..…P50
4.6 Vibrator Trouble………………………………………………………………………………........P52
4.7 LCD Trouble…………………………………………………………………………......................P54
4.8 Speaker Trouble…………………………………………………………………………...............P56
4.9 SIM Card Interface Trouble……………………………………………………………………….P58
4.10 Earphone Trouble……………………………………………………………………..…............P60
4.11 KEY backlight Trouble……………………………………………………………………….…..P62
4.12 Microphone Trouble…………………………………………………….………….………........P64
4.13 RTC Trouble……………………………………………………………….………......................P66
4.14 Folder on/off Trouble………………………………………………………………..……….......P68
5. Circuit and PCB Layout…………………………………………………………….P70
6. ENGINEERING MODE………………………………………….…………………….P77
7. STAND ALONE TEST……………………………………………………..…………..P78
8. CALIBRATION………………………………………………………………………………P81
9. Download…………………………………………………………….………………………...P89
10.Total ASSY……………………………………………………………………...…………….P94
11.Appendix
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1. INTRODUCTION
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1.1 Purpose
This manual provides the information necessary to repair, 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 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. 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
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1. INTRODUCTION
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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
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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1. INTRODUCTION
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1.3 Abbreviations
For the purposes of this manual, following abbreviations apply:
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 milli watt
DSP Digital Signal Processing
EEPROM Electrical Erasable Programmable Read-Only Memory
ESD 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
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1. INTRODUCTION
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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
RTC Real Time Clock
SAW Surface Acoustic Wave
SIM Subscriber Identity Module
SLR Sending Loudness Rating
SRAM Static Random Access Memory
PSRAM Pseudo SRAM
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
VCTCXO Voltage Control Temperature Compensated Crystal Oscillator
WAP Wireless Application Protocol
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2. PERFORMANCE
2.1 H/W Features
Item Target Specification
Standard Battery Li-ion,830mAh
Stand by TIME Up to 200 hrs: Paging Period 9,RSSI 85dBm
Talk TIME Up to 200 min: GSM Tx Level 7()
Charging TIME Approx.2 hrs
RX Sensitivity GSM850: -109dBm,PCS: -109dBm
TX Output power GSM850:32.5dBm(Level 5),
PCS:29.5dBm(Level 0)
GPRS compatibility Class 10
SIM card type 3V
Display LCD:CSTN 128X128 65K,SubLCD 96X64
MONO
Status Indicator Hard Icons. Key Pad 0-9,#,*,Up/Down
Navigation Key, Menu Key, Clear Key Send
Key, END/PWR Key Soft Key (Left/Right)
ANT Internal
EAR Phone Jack Yes(MONO)
PC Synchronization No
Speech coding EFR/FR/HR
Data and Fax Yes
Vibrator Yes
Loud Speaker Yes
Voice Recoding No
Microphone Yes
Speaker/Receiver One way Speaker
Travel Adapter Yes
MIDI 40 Poly (Mono SPK)
Camera No
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2.2 Technical Specification
Item Description Specification
1
Frequency Band
GSM850
TX:824.2MHz-848.8MHz
RX:869.2MHz-893.8MHz
CHN: 128-251
PCS
TX:1850.2MHz-1909.8MHz
RX:1930.2MHz-1989.8MHz
CHN: 512-810
2 Phase Error RMS<5 degrees
Peak<20 degrees
3 Frequency Error <0.1 ppm
GSM850
Level Power Toler Level Power Toler
5 33dBm ±2dB 13 17dBm
±3dB
6 31dBm ±3dB 14 15dBm
±3dB
7 29dBm ±3dB 15 13dBm
±3dB
8 27dBm ±3dB 16 11dBm
±5dB
9 25dBm ±3dB 17 9dBm
±5dB
10 23dBm ±3dB 18 7dBm
±5dB
11 21dBm ±3dB 19 5dBm
±5dB
12 19dBm ±3dB
PCS
Level Power Toler Level Power Toler
0 30dBm ±2dB 8 14dBm
±3dB
1 28dBm ±3dB 9 12dBm
±4dB
2 26dBm ±3dB 10 10dBm
±4dB
3 24dBm ±3dB 11 8dBm
±4dB
4 22dBm ±3dB 12 6dBm
±4dB
5 20dBm ±3dB 13 4dBm
±4dB
6 18dBm ±3dB 14 2dBm
±5dB
4
Power Level
7 16dBm ±3dB 15 0dBm
±5dB
2. PERFORMANCE
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2. PERFORMANCE
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Item Description Specification
GSM850
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600~ <1,200 -60
1,200~ <1,800 -60
1,800~ <3,000 -63
3,000~ <6,000 -65
5Output RF Spectrum 6,000 -71
(due to modulation) PCS
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600~ <1,200 -60
1,200~ <1,800 -60
1,800~ <3,000 -65
3,000~ <6,000 -65
6,000 -73
GSM850
Offset from Carrier (kHz) Max. (dBm)
Output RF Spectrum 400 -19
6(due to switching transient) 600 -21
1,200 -21
1,800 -24
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2. PERFORMANCE
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Item Description Specification
PCS
Offset from Carrier (kHz). Max. (dBm)
Output RF Spectrum 400 -22
6(due to switching transient) 600 -24
1,200 -24
1,800 -27
7 Spurious Emissions Conduction, Emission Status
GSM850
8 Bit Error Ratio BER (Class II) < 2.439% @-102 dBm
PCS
BER (Class II) < 2.439% @-100 dBm
9 RX Level Report Accuracy 3 dB
10 SLR 8 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 0 -12
11 Sending Response 1,000 0 -6
2,000 4 -6
3,000 4 -6
3,400 4 -9
4,000 0 -
12 RLR 2 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 2 -7
500 *-5
13 Receiving Response 1,000 0 -5
3,000 2 -5
3,400 2 -10
4,000 2
*Mean that Adopt a straight line in between 300 Hz
and 1,000 Hz to be Max. level in the range.
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2. PERFORMANCE
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Item Description Specification
14 STMR 13 5 dB
15 Stability Margin > 6 dB
dB to ARL (dB) Level Ratio (dB)
-35 17.5
-30 22.5
-20 30.7
16 Distortion -10 33.3
0 33.7
7 31.7
10 25.5
17 Side Tone Distortion Three stage distortion < 10%
18 System frequency 2.5ppm
(13 MHz) tolerance
19 32.768KHz tolerance 30ppm
At least 65 dBspl under below conditions:
20 Ringer Volume 1. Ringer set as ringer.
2. Test distance set as 50 cm
21 Charge Current Fast Charge : < 430 mA
Slow Charge : < 160 mA
Antenna Bar Number Power
5 -85 dBm ~
4 -90 dBm ~ -86 dBm
22 Antenna Display 3 -95 dBm ~ -91 dBm
2 -100 dBm ~ -96 dBm
1 -105 dBm ~ -101 dBm
0 ~ -105 dBm
Battery Bar Number Voltage
0 3.48 ~ 3.63 V
23 Battery Indicator 1 3.63 ~ 3.70 V
2 3.70 ~ 3.76 V
3 3.76 ~ 3.89 V
4 3.89 V ~
24 Low Voltage Warning 3.63 0.03V (Call) every 1 minutes
3.48 0.03V (Standby)
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2. PERFORMANCE
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Item Description Specification
25 Forced shut down Voltage 3.33 0.03 V
1 Li-ion Battery
26 Battery Type Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: 830mAh
Switching-mode charger
27 Travel Charger Input: 100 ~ 240 V, 50/60 Hz
Output: 5.2 V, 800 mA
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3. TECHNICAL BRIEF
3.1 MG120 Block Diagram
Figure 3-1 TOP LEVEL BLOCK OF MG120
The Figure 3-1 shows the top level block diagram of MG120, it contains
RF and BB part. The following list is the detailed.
1. AD6720:ADI baseband chipset,
2. PA+FEM:RF3166 is The PAM and HWXQ512 is the FEM
3. Transceiver: SI4210
4. Flash: Spansion 32Mb+64Mb
5. Others
A: 22 keys
B: 128*128 65K CSTN Main LCD and 96*64 MONO FSTN Sub LCD
C: Vibrator, Mic, Speaker, Ear-jack
D: Sim socket
E: Battery connector
3. TECHNICAL BRIEF
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3.2 RF Part Introductions
The RF part consists of a power amplifier part, a transmitter
part, a crystal reference system, and an ant-switch part.
3.2.1 Power Amplifier (RF3166, U102)
The RF3166 is a high-power, high-efficiency power amplifier module with integrated power
control that provides over 50dB of control range. The device is a self-contained 6mmx6mm
module with 50Ωinput and output terminals. The device is designed for use as the final RF
amplifier inGSM850, EGSM900, DCS and PCS handheld digital cellular equipment and
other applications in the 824MHz to849MHz, 880MHz to 915MHz, 1710MHz to 1785MHz
and 1850MHz to 1910MHz bands. The RF3166 incorporates RFMD’s latest VBATT tracking
circuit, which monitors battery voltage and prevents the power control loop from reaching
saturation. The VBATT tracking circuit eliminates the need to monitor battery voltage,
thereby minimizing switching transients. The RF3166 requires no external routing or
external components, simplifying layout and reducing board space.
Figure 3-2 Functional Block Diagram
3. TECHNICAL BRIEF
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Figure 3-3 RF3166 PAM Pin Configuration-9-Pin
Table 3-1. RF3166 Pin Names and Signal Descriptions
PIN Function Description
1 DCS/PCS
IN RF input to the DCS band. This is a 50ohm input
2 BAND
SELECT Logic Low enable GSM band Logic HIGH enable DCS/PCS band
3 TX
ENABLE Enable PA module for operation with a logic high
4 VBATT
Power supply for the module
5 GND
6 VRAMP
Ramping signal from DAC. No external filtering is required
7 GSM IN
50ohm input pin for GSM band
8 GSM OUT
50ohm output pin for GSM band
9 DCS/PCS
OUT 50ohm output pin for DCS/PCS band
Pkg
Base
GND
3. TECHNICAL BRIEF
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3.2.2 Transceiver (SI4210, U103)
The SI4210 transceiver is a complete RF front end for multi-band GSM and GPRS wireless
communications. The receive section interfaces between the RF band-select SAW filters and
the baseband subsystem. The Aero II receiver leverages a proven digital low-IF architecture
and enables a universal baseband interface without the need for complex dc offset
compensation. The transmit section of Aero II provides a complete upconversion path from
the baseband subsystem to the power amplifier (PA) using an offset phase-locked loop (OPLL)
integrated with Silicon Laboratories’ patented synthesizer technology. All sensitive
components, such as TX/RF VCOs, loop filters, tuning inductors, and varactors are completely
integrated into a single integrated circuit. The Aero II transceiver includes a digitally-controlled
crystal oscillator (DCXO) and completely integrates the reference oscillator and varactor
functionality.
Figure 3-4 Functional Block Diagram
3. TECHNICAL BRIEF
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Table 3-2. SI4210 Pin Names and Signal Descriptions
Pin Number(s) Name
1 SCLK Serial clock input
2 SEN Serial enable input ( active low)
3 SDIO Serial data input/output
4,5 BQP,BQN Transmit/receiver Q input/output
6,7 BIP,BIN Transmit/receiver I input/output
8 XOUT Clock output to baseband
9 PDN Power down input
10 RESET Reset pin
11 VIO Interface supply voltage
12,13,28,29 VDD supply voltage
14,PAD GND Ground
15 RFOL GSM 850 and EGSM 900 output
16 RFOH DCS 1800 and PCS 1900 output
17,18 RFIPP,RFIPN PCS 1900 LNA input
19,20 RFIDP,RFIDN DCS 1800 LNA input,
21,22 RFIEP,RFIEN EGSM 900 LNA input
23,24 RFIAP,RFIAN GSM 850 LNA input
25 XMODE DCXO/VC-TCXO mode enable
26 XDIV XOUT frequency select input
27 AFC Baseband analog AFC input
30,31 XTAL2,XTAL1 Crystal output and input
32 XEN XOUT pin enable
3. TECHNICAL BRIEF
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3.2.3 FEM (HWXQ512,U104)
Table 3-3 Band SW Logic Table
Select Mode Vc(GSM) Vc(DCS/PCS)
GSM-Rx Low Low
GSM-Tx High Low
DCS-Rx Low Low
PCS-Rx Low Low
DCS/PCS-Tx Low High
3.2.4 26MHz Clock (TG-5000LA, X100)
The 26MHz clock (X100) consisits of a TCXO(Temperature Compensated Crystal Oscillator)
which oscillator at a frequency of 26 MHz. It is used within the RF part and DBB part.
3. TECHNICAL BRIEF
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