LG MG810c User manual

Date: May, 2006 / Issue 1.0
Service Manual
MG810c/MG810d
Service Manual Model : MG810c/MG810d

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 KG810
REVISED HISTORY
DATE ISSUE CONTENTS OF CHANGES S/W VERSION
Mar / 2006 ISSUE 1 Initial Release

- 2 -

- 3 -
1. Introduction ........................................ 5
1.1 Purpose ...................................................... 5
1.2 Regulatory Information ............................... 5
2. General Performance ......................... 7
2.1 H/W Features.............................................. 7
2.2 Technical Specification ............................... 8
2.3 S/W Features.............................................12
2.4 H/W Features.............................................10
2.5 S/W Features.............................................12
3. H/W Circuit Description ................... 13
3.1 RF Transceiver General Description ........ 13
3.2 Receiver Part ............................................ 13
3.2.1. RF Front End...........................................14
3.2.2. Low IF .....................................................15
3.2.3. Demodulator and Baseband
Processing ..............................................15
3.3 Synthesizer Part ....................................... 15
3.3.1. VCTCXO .................................................16
3.4 Transmitter Part .........................................16
3.4.1. IF Modulator ............................................17
3.4.2. OPLL .......................................................17
3.4.3. Power Ampifier Module ...........................17
3.4.4. Power Supplies and Control Signals.......18
3.5 Digital Baseband....................................... 19
3.6 Analog Baseband ......................................33
3.7 LCD & Camera Interface ...........................37
3.8 Bluetooth Interface.....................................39
3.8.1. Bluetooth circuit Description....................40
4. TROUBLE SHOOTING...................... 41
4.1 Baseband Part Troubleshooting ............... 41
4.2 RF Part Troubleshooting........................... 59
4.3 Bluetooth Trouble ..................................... 74
5. DOWNLOAD...................................... 77
5.1 H/W Tool Setup ........................................ 77
5.2 Install & Directory structure........................78
5.3 Configuration setting..................................79
5.4 Download sequence ..................................82
6. Block Diagram .................................. 83
7. CIRCUIT DIAGRAM........................... 85
8. PCB LAYOUT .................................... 95
9. Calibration.............................................. 101
9.1 H/W Tool Setup .......................................101
9.2 Install & Directory structure......................104
9.3 Others Directory structure of CM_GSM...105
9.4 Cal. Procedure.........................................106
9.5 Cal. sequence..........................................107
10. ENGINEERING MODE...................... 108
11. STANDALONE TEST .....................109
11.1 Setting Method.......................................109
11.1.1 COM Port .............................................109
11.1.2 Tx Test .................................................109
11.1.3 Rx Test.................................................109
12. EXPLODED VIEW & REPLACEMENT
PART LIST ..................................... 111
12.1 EXPLODED VIEW ................................ 111
12.2 Replacement Parts
<Mechanic component> ....................... 113
<Main component> ............................... 116
12.3 Accessory ............................................. 131
Table of Contents

1. Introduction
- 5 -
1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of the CG225
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 CG225 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 CG225 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 CG225 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 CG225 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
- 7 -
2.1 H/W Features
2. PERFORMANCE
Item Feature Comment
Standard Battery Li-Ion, 700mAh
AVG TCVR Current 240mA
Standby Current < 5.2mA
Talk time Over 3 hour (@GSM Tx Level 7)
Standby time Over 200 hour(@ Paging Period 9, RSSI : -85dBm)
Charging time 3 hours
RX Sensitivity GSM900 : -105dBm, DCS/PCS : -105dBm
TX output power GSM, EGSM: 32dBm (Level 5)
DCS/PCS: 29dBm (Level 0)
GPRS compatibility Class 12
SIM card type 3.0V Only
Display Main : 176 x 220 TFT, Sub : 96 x 96 TFT
Key Pad(Main) : 0 ~ 9, #, *, Navigation Key,
Up/Down Side Key, Camera Side Key,
Status Indicator Confirm Key, Send Key, END/PWR Key
Key Pad(Folder) : Rewind, Fasten Forward, Play
ANT Internal
EAR Phone Jack 18-pin
PC Synchronization Yes
Speech coding EFR / FR
Data and Fax Yes
Vibrator Yes
Buzzer No
Voice Recoding Yes
MEMS-Mic Yes
Receiver Yes
Travel Adapter Yes
Options MLA

2. PERFORMANCE
- 8 -
2.2 Technical Specification
Item Description Specification
GSM900
TX: 890 + n x 0.2 MHz (n=1 ~ 124)
890 + (n-1024) x 0.2 MHz (n=975 ~ 1023)
RX: TX + 45 MHz
DCS1800
1Frequency Band TX: 1710 + ( n-511 ) x 0.2 MHz (n = 512 ~ 885)
RX: TX + 95 MHz
PCS1900
TX: 1850 + ( n-511 ) x 0.2 MHz
RX: 1930 + ( n-511 ) x 0.2 MHz (n = 512 ~ 810)
2Phase Error RMS < 5 degrees
Peak < 20 degrees
3Frequency Error < 0.1 ppm
GSM900
Level Power Toler. Level Power Toler.
533 dBm 2dB 13 17 dBm 3dB
631 dBm 3dB 14 15 dBm 3dB
729 dBm 3dB 15 13 dBm 3dB
827 dBm 3dB 16 11 dBm 5dB
925 dBm 3dB 17 9 dBm 5dB
10 23 dBm 3dB 18 7 dBm 5dB
11 21 dBm 3dB 19 5 dBm 5dB
4Power Level 12 19 dBm 3dB
DCS1800/PCS1900
Level Power Toler. Level Power Toler.
030 dBm 2dB 8 14 dBm 3dB
128 dBm 3dB 9 12 dBm 4dB
226 dBm 3dB 10 10 dBm 4dB
324 dBm 3dB 11 8 dBm 4dB
422 dBm 3dB 12 6 dBm 4dB
520 dBm 3dB 13 4 dBm 4dB
618 dBm 3dB 14 2 dBm 5dB
716 dBm 3dB 15 0 dBm 5dB

2. General Performance
- 9 -
Item Description Specification
GSM900
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) DCS1800/PCS1900
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
GSM900
Offset from Carrier (kHz) Max. (dBm)
Output RF Spectrum 400 -19
6(due to switching transient) 600 -21
1,200 -21
1,800 -24

2. General Performance
- 10 -
Item Description Specification
DCS1800/PCS1900
Offset from Carrier (kHz). Max. (dBm)
Output RF Spectrum 400 -22
6(due to switching transient) 600 -24
1,200 -24
1,800 -27
7Spurious Emissions Conduction, Emission Status
GSM900
8Bit Error Ratio BER (Class II) < 2.439% @-102dBm
DCS1800/PCS1900
BER (Class II) < 2.439% @-100dBm
9RX 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.

2. General Performance
- 11 -
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
033.7
731.7
10 25.5
17 Side Tone Distortion Three stage distortion < 10%
18 <Change> System frequency 2.5ppm
(13 MHz) tolerance
19 <Change>32.768KHz tolerance 30ppm
Standby
20 Ringer Volume - Normal ≤ 5.2mA(Mix. power)
21 Talk Time GSM900/Lvl 7 (Battery Capacity 700mA):180 min
GSM900/Lvl 12(Battery Capacity 700mA):240 min
Under conditions, at least 200 hours:
1. Brand new and full 700mAh battery
2. Full charge, no receive/send and keep GSM in idle mode.
22 Antenna Display 3. Broadcast set off.
4. Signal strength display set at 3 level above.
5. Backlight of phone set off.
At least 55 dB under below conditions:
23 Ringer Volume 1. Ringer set as ringer.
2. Test distance set as 100 cm
24 Charge Voltage Fast Charge : < 500 mA
Slow Charge: < 60 mA

2.3 S/W Features
2. General Performance
- 12 -
Item Description Specification
Antenna Bar Number Power
5-85 dBm ~
4-90 dBm ~ -86 dBm
25 Antenna Display 3 -95 dBm ~ -91 dBm
2-100 dBm ~ -96 dBm
1-105 dBm ~ -101 dBm
0~-105 dBm
03.62V 0.03V
13.70V 0.03V
26 Battery Indicator 2 3.78V 0.03V
33.91V 0.03V
43.92V 0.03V➚
27 Low Voltage Warning 3.62V➘0.03V (Call)
3.50V➘0.03V (Standby)
28 Forced shut down Voltage 3.35 0.03 V
1 Li-ion Battery
29 Battery Type Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: 700mAh
Switching-mode charger
30 Travel Charger Input: 100 ~ 240 V, 50/60Hz
Out put: 4.8V, 900mA

3. H/W Circuit Description
- 13 -
3. H/W Circuit Description
3.1 RF Transceiver General Description
The RF parts consist of a transmitter part, a receiver part, a frequency synthesizer part, a voltage
supply part, and a VCTCXO part.
The SI4210[U401] is a triple band transceiver IC suitable for GSM 900, DCS 1800 and PCS 1900
GPRS class 12 applications. This device integrated a receiver based on a low IF (100KHz)
architecture and a transmitter based on modulation loop architecture. And, the synthesizer part are
included in the IC, a complete dual band synthesizer with built in VCOs.
The transceiver employed a 3 wire serial interface to allow an external system controller to write the
control registers for dividers, receive path gain, power down setting, and other controls.
3.2 Receiver Part
The receiver part uses a low-IF receiver architecture that allows for the on-chip integration of the
channel selection filters, eliminating the external RF image reject filters and the IF SAW filter required
in conventional super-heterodyne architecture. The SI4210[U401] integrates three differential input
LNAs that are matched to the 200 Ohm balanced-output SAW filters through external LC matching
networks. A quadrature image-rejection mixer downconverts the RF signal to a 100kHz intermediate
frequency (IF) with the RFLO.
The mixer output is amplified with an analog programmable gain amplifier (PGA) and quadrature IF
signal is digitized with high resolution A/D converters (ADCs). The SI4210[U401] downconverts the
ADC output to baseband with a digital 100kHz quadrature LO signal. Digital decimation and IIR filters
perform channel selection to remove blocking and reference interference signals. After channel
selection, the digital output is scaled with digital PGA, which is controlled with the DGAIN[5:0] bits in
register 05h.The amplified digital output signal go through with DACs that drive a differential analog
signal onto the RXIP,RXIN,RXQP and RXQN pins to interface to standard analog ADC input baseband
ICx.
Table 3-1. Antenna(RSSI) Display
Antenna Bar Number Rx Power (dBm)
5≥-85
4≥-90
Antenna Display 3≥-95
2≥-100
2≥-105
1<-105

3.2.1. RF Front End
RF front end consists of Antenna Switch Module with SAW filter for triple band(FL400), triple band
LNAs integrated in transceiver(U401).
The Received RF signals (EGSM 925MHz ~ 960MHz, DCS 1805MHz ~ 1880MHz, PCS 1850 ~
1990MHz) are fed into the antenna or mobile switch. An antenna matching circuit is between the
antenna and the mobile switch. The Antenna Switch(in FL400) is used for control the Rx and TX paths.
And, the input signals ANT1,ANT2 of a FL400 are directly connected to baseband controller to switch
either TX or RX path on and select bands. Ant S/W module(FL400) is an antenna switch module for
dual band phone. The logic and current is given below.
The receiver part uses a low-IF receiver architecture that allows for the on-chip integration of the
channel selection filters, eliminating the external RF image reject filters and the IF SAW filter required
in conventional super-heterodyne architecture. The SI4210[U401] integrates three differential input
LNAs that are matched to the 200 ohm balanced-output SAW filters through external LC matching
networks.
3. H/W Circuit Description
- 14 -
Figure 1. RECEIVER PART Block Diagram
Table 3-2. BAND/RTX SELECTION
ANT_SW1 ANT_SW2
GSM 850_EGSM RX L L
GSM-850_EGSM TX L H
DCS/PCS RX H L
DCS/PCS TX H H

3. H/W Circuit Description
- 15 -
3.2.2. Low IF
A quadrate image-rejection mixer downconverts the RF signal to a 100kHz intermediate frequency (IF)
with the RFLO . The RFLO frequency is between 1849.8 and 1918.8 MHz, and is divided by two for
EGSM modes. The RFLO frequency is between 1804.9 and 1879.9 MHz, and is divided by one for
DCS modes. The RFLO frequency is between 1929.9 and 1989.9 MHz, and is divided by one for PCS
modes. The mixer output is amplified with an analog programmable gain amplifier (PGA), which is
controlled with the AGAIN[2:0] bits in register 05h. The quadrate IF signal is digitized with high
resolution A/D converters (ADCs). The Si4210[U401] down-converts the ADC output to baseband with
a digital 100kHz quadrate LO signal. Digital decimation and IIR filters perform channel selection to
remove blocking and reference interference signals. The response of the IIR filter is programmable to
a high selectivity setting(CSEL=0) or a low selectivity setting (CSEL=1). After channel selection, the
digital output is scaled with digital PGA, which is controlled with the DGAIN[5:0] bits in register 05h.
3.2.3. Demodulator and Baseband Processing
The amplified digital output signal go through with DACs that drive a differential analog signal onto the
RXIP, RXIN, RXQP and RXQN pins to interface to standard analog ADC input baseband ICs. No
special processing is required in the baseband for offset compensation or extended dynamic range.
Compared to a direct-conversion architecture, the low-IF architecture has a much greater degree of
immunity to dc offsets that can arise from RF local oscillator(RFLO) self-mixing, 2nd order distortion of
blockers, and device 1/f noise.
3.3 Synthesizer Part
The Si4210[U401] integrates two complete PLLs including VCOs, varactors, resonators, loop filters,
reference and VCO dividers, and phase detectors. The RF PLL uses two multiplexed VCOs. The RF1
VCO is used for receive mode, and the RF2 VCO is used for transmit mode. The IF PLL is used only
during transmit mode. All VCO tuning inductors are also integrated. The IF and RF output frequencies
are set by programming the N-Divider registers, NRF1, NRF2, and NIF. Programming the N-Divider
register for either RF1 or RF2 automatically selects the proper VCO. The output frequency of each
PLL is as follows:
FOUT = N x fφ
A programmable divider in the input stage allows either a 13 or 26 MHz reference requency depending
on the choice of crystal. A 26 MHz reference clock can be divided by 2 using the DIV2 bit in Register
31h. The RF PLL phase detector update rate (fφ) can be programmed with the RFUP bit in register
31h to either fφ= 100 kHz or fφ= 200 kHz. The IF PLL always uses fφ= 200 kHz. Receive mode
should use fφ= 100 kHz in DCS 1800 and PCS 1900 bands, and fφ= 200 kHz in the E-GSM 900
bands. Transmit modes should always use fφ= 200 kHz.

3.3.1. VCTCXO
The VCTCXO module supply 26MHz reference clock and controlled by AFC input to generate a
precise system reference clock adjustment.
The 26 MHz clock(X500) consists of a TCXO(Temperature Compensated Crystal Oscillator) which
oscillates at a frequency of 13 MHz. It is used within the TRF6151C RF Main Chip, BB Analog chip-
set(IOTA), Digital chip-set(Calypso Lite).
3.4 Transmitter Part
The Transmitter part contains SI4210[U401] active parts, Power Amp Module[U400] and Antenna
Switch Module[FL400]. The transmit section of SI4210[U401] consists of an I/Q baseband pconverter,
an offset phaselocked loop (OPLL) and two 50 ohm output buffers that can drive external power
amplifiers. The RF GMSK outputs from the transmit VCO are fed directly to the RF power amplifiers.
The peak output power and the profile of the transmitted burst are controlled by means of incorporated
power control circuits inside of PA and DAC output. from the Baseband Controller. The PA outputs
pass to the antenna connector via Antenna Switch Module.
3. H/W Circuit Description
- 16 -
Figure 4. VC-TCXO Circuit
BT_26MHZ
26MHzX401
2GND
3
OUT
VCC 4
VCONT
1
C428
1000p
RF2.85V
R550
100K
RF2.85V
1000p
C999
C430
1u 1000p
C429
15K
R425
C431
1000p
TCXO_OUT
AFC
Figure 3. TRANSMITTER PART Block Diagram

3. H/W Circuit Description
- 17 -
3.4.1. IF Modulator
The baseband converter(BBC) within the GSM chipset generates I and Q baseband signals for the
Transmit vector modulator. The modulator provides more than 40dBc of carrier and unwanted
sideband. Rejection and produces a GMSK modulated signal. The baseband software is able to
cancel out differential DC offsets in the I/Q baseband signals caused by imperfections in the D/A
converters. The TX-Modulator implements a quadrature modulator. A quadrature mixer upconverts the
differential I/Q signals with the IFLO to generate a SSB IF signal, which is filtered and used as the
reference input to the OPLL. The SI4210[U401] generates the IFLO frequency. The IFLO is divided by
two to generate the quadrature LO signals for the quadrature modulator.
3.4.2. OPLL
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 E-GSM 900 bands. The Si4206 generates the RFLO frequency between 1327 and
1402 MHz. To allow a single VCO to be used for the RFLO, high-side injection is used for the 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
3.4.3. Power Ampifier Module
The RF3166[U400] is a triple-band GSM/DCS/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 typical 50 dB of control range with an analog voltage input (Vapc).
Efficiency is 53% at GSM, DCS and PCS.

3.4.4. Power Supplies and Control Signals
An external regulator(U303) is used to provide DC power to RF part. Every RF component except
power amp module uses this external regulator.
3. H/W Circuit Description
- 18 -
Figure 4. POWER AMP
Figure 5 POWER SUPPLIE & CONTROL
14/89

3. H/W Circuit Description
- 19 -
3.5 Digital Baseband
A. General Description
• Calypso-Plus device is an evolution of Calypso(C035) device integrating hardware enhancements
targeting the implementation of a new range of user’s applications.
• It supports the digital baseband processing of GSM radio signals in switching circuit mode and
packet data mode up to class 12 in compliance with the ETSI specification of the GPRS protocol.
• The functional enhancement of the Calypso-Plus offer an increase computing performance of both
ARM7 based MCU and C54x based DSP sub-system in addition to numerous new connectivity.
Figure 7. Top level block diagram of the Calypso-Plus