LG B2070 User manual

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edoM B2000
Service Manual
B2000
P/N : MMBD0047201 Date : March 2005/ Issue 1.0
Date: October, 2005 / Issue 1.0
Service Manual
B2070
Model : B2070

Table Of Contents
1. INTRODUCTION..........................2
1.1 Purpose ...........................................2
1.2 Regulatory Information ....................2
1.3 Abbreviations ..................................4
2. PERFORMANCE ........................ 6
2.1 H/W Feature ...................................6
2.2 Technical Specification ..................8
3. TECHNICAL BRIEF ..................13
3.1 Transceiver ...................................13
3.2 Power Amplifier Module ..................19
3.3 13 MHz Clock ............................... 20
3.4 Power Supplies of RF circuits ........20
3.5 Digital Main Processor ...................22
3.6 Analog Main & Power
Management Processor ................28
3.7 Display Interface ............................. 38
3.8 Radio Interface ..............................40
3.9 Keypad Switches and Scanning .... 41
3.10 Microphone ..................................42
3.11 Main Speaker ............................. 42
3.12 Headset interface ........................43
3.13 Key Back-light Illumination .......... 44
3.14 Vibrator ........................................45
4. TROUBLE SHOOTING ............. 46
4.1 RX Trouble ................................... 46
4.2 TX Trouble ................................... 53
4.3 Power On Trouble .........................61
4.4 Charging Trouble........................... 63
4.5 Vibrator Trouble..............................65
4.6 LCD Trouble.................................. 67
4.7 Radio Trouble ................................69
4.8 Speaker Trouble .............................71
4.9 SIM card interface trouble ............ 74
4.10 Earphone Trouble .........................76
4.11 Key Backlight Trouble ..................78
4.12 Receiver Trouble ..........................80
4.13 Microphone Trouble .................... 82
4.14 RTC Trouble .................................84
4.15 Indication LED Trouble..................86
4.16 PTT Trouble .................................88
4.17 Speakerphone Trouble ..................89
5. DOWNLOAD AND
CALIBRATION .......................91
5.1 Download .......................................91
5.2 Calibration .......................................96
6. BLOCK DIAGRAM.....................99
7. CIRCUIT DIAGRAM .................101
8. PCB LAYOUT .........................106
9. ENGINEERING MODE .............109
9.1 BB Test [MENU 1] .........................110
9.2 RF Test [MENU 2] .........................111
9.3 MF mode [MENU 3].......................112
9.4 Trace option [MENU 4] ..................113
9.5 Call timer [MENU 5] ......................113
9.6 Fact. Reset [MENU 6] ...................113
9.7 S/W version [MENU 7] ..................113
10. STAND ALONE TEST.............114
10.1 Introduction ...............................114
10.2 Setting Method............................114
10.3 Means of Test ............................115
11. AUTO CALIBRATION ...........117
11.1 Overview.....................................117
11.2 Requirements..............................117
11.3 Menu and Settings ......................117
11.4 AGC............................................119
11.5 APC............................................119
11.6 ADC............................................119
11.7 Setting........................................119
11.8 How to do calibration...................119
12. EXPLODED VIEW &
REPLACEMENT PART LIST ..121
12.1 Exploded View............................121
12.2 Replacement Parts
<Mechanic component>...............123
<Main component>......................125
12.3 Accessory ....................................138

- 2 -
1. INTRODUCTION
1. INTRODUCTION
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 byan 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
Alocal 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.

- 3 -
1. INTRODUCTION
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
systemboards.
• 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.

- 4 -
1. INTRODUCTION
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
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
EEPROM Electrical Erasable Programmable Read-Only Memory

- 5 -
1. INTRODUCTION
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
SAW Surface Acoustic Wave
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

- 6 -
2. PERFORMANCE
2. PERFORMANCE
2.1 H/W Features
Item Feature Comment
Li-ion, 780 mAh
Standard Battery Battery Size: 105.5(W) x 44(H) x 15.8(T) [mm]
Battery Weight: TBD
Under the minimum current consumption environment
Stand by Current (such as paging period 9), the level of standby current
is below 4mA.
Stand by time Up to 200 hours (Paging Period: 9, RSSI: -85 dBm)
Charging time Approx. Under 3.75 hours
RX Sensitivity GSM, EGSM: –104dBm, DCS: –104dBm
TX output power GSM, EGSM: 33dBm (Level 5),
DCS PCS: 30dBm (Level 0)
GPRS compatibility Class 10
SIM card type 3V Small Only
Display Main LCD : CSTN 128 x 128 pixel 65K Color
Hard icons. Key Pad
Status Indicator 0 ~ 9, #, *, 4
Menu Key, Clear Key
Send Key, END/PWR Key
ANT Internal
EAR Phone Jack Yes
PC Synchronization Yes
Speech coding EFR/FR/HR
Data and Fax
Vibrator Yes
Yes
Loud Speaker No
Voice Recording Yes
Soft Key(Left/Right)
(stereo)
Microphone Yes
Talk time Up to 2 hours (GSM TX Level 5)

- 7 -
2. PERFORMANCE
Item Feature Comment
Speaker / Receiver One way dual speaker
Travel Adapter Yes
MP3/AAC
Options Data Cable
MIDI 40 Poly (Mono SPK)
No

- 8 -
2. PERFORMANCE
2.2 Technical Specification
I
I
tem Description Specification
1Frequency Band
TX : 890 + (n-1024) × 0.2 MHz
RX : 935 + (n-1024) × 0.2 MHz (n=975~1024)
EGSM
TX : 1710 + (n -512) × 0.2 M z
RX : 1805 + (n –512) x 0.2 MHz (n=512~885)
D
P
CS
CS
TX : 1810 + (n-512) × 0.2 MHz
RX : 1905 + (n-512) × 0.2 MHz (n=512~885)
2 Phase Error RMS < 5 degrees
Peak < 20 degrees
3Frequency Error < 0.1 ppm
4PowerLevel
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
10 23dBm ±3dB 18 7dBm ± 5dB
11 21dBm ±3dB 19 5dBm ± 5dB
12 19dBm ±3dB
GSM,EGSM
EGSM
,
5 33dBm ±2dB 13 17dBm ± 3dB
Level Power Toler. Level Power Toler.
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
7 16dBm ±3dB 15 0dBm ± 5dB
DCS
SCS
PCS
0 30dBm ±2dB 8 14dBm ± 3dB

- 9 -
2. PERFORMANCE
Item Description Specification
GSM, EGSM
Offset from Carrier (kHz). Max. dBc
100
200
250
400
600 ~ <1,200
1,200 ~ <1,800
1,800 ~ <3,000
3,000 ~ <6,000
5 Output RF Spectrum 6,000
(due to modulation)
DCS, PCS,
Offset from Carrier (kHz). Max. dBc
100
200
250
400
600 ~ <1,200
1,200 ~ <1,800
1,800 ~ <3,000
3,000 ~ <6,000
6,000
GSM, EGSM
Offset from Carrier (kHz). Max. dBm
400
600
1,200
1,800
(due to switching
transient)
6 Output RF Spectrum
–30
–33
–60
–60
–60
–63
–65
–71
+0.5
–30
–33
–60
–60
–60
–65
–65
–73
+0.5
–19
–21
–21
–24

- 10 -
2. PERFORMANCE
Item Description Specification
GSM, EGSM
, EGSM
8 Bit Error Ratio BER (Class II) < 2.439% @–102 dBm
DCS
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
+
_
+
_
+
_
7Spurious Emissions Conduction, Emission Status
(due to switching
DCS, PCS
transient)
Offset from Carrier (kHz). Max. dBm
400 –22
600 –24
1,200 –24
1,800 –27
6 Output RF Spectrum

- 11 -
2. PERFORMANCE
Item Description Specification
Frequency (Hz) Max. (dB) Min. (dB)
100 –12 –
200 0 –
300 2 –7
500 –5
13 Receiving Respons 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.
14 STMR 13 5 dB
15 Stability Margin > 6 dB
dB to ARL (dB) Level Ratio (dB)
–35 17.5
–30 22.5
16 Distortion
–20 30.7
–10 33.3
0 33.7
7 31.7
10 25.5
17 Side Tone Distortion Three stage distortion < 10%
18 System Frequency ≤ 2.5 ppm
(13 MHz) Tolerance
19 32.768KHz Tolerance ≤ 30 ppm
+
_
At least 65 dBspl under below conditions:
20 Ringer Volume 1. Ringer set as ringer.
2. Test distance set as 50 cm.
*
*

- 12 -
2. PERFORMANCE
Item Description Specification
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 3.36 ~ 3.58V
23 Battery Indicator
1 3.59 ~ 3.66V
2 3.67 ~ 3.73V
3 3.74V ~ 3.87V
24 Low Voltage Warning
3.50 0.03V (Standby)
3.59 0.03V (Call)
25 Forced shut down 3.35 0.03V
Voltage
1 Li-ion Battery
26 Battery Type Standard Voltage = 3.7V
Battery full charge voltage = 4.2V
Capacity : 780mAh
Switching-mode charger
27 Travel Charger Input : 100 ~ 240V, 50/60 Hz
Output : 5.2V, 800 mA
4 3.88V ~
+
_
+
_
+
_

3. TECHNICAL BRIEF
- 13 -
3. TECHNICAL BRIEF
3.1 Transceiver (SI4205-BM, U500)
The RF parts consist of a transmitter part, a receiver part, a frequency synthesizer part, a
voltagesupply part, and a VCTCXO part.
The Aero I transceiver is the integrated RF front end for multi-band GSM/GPRS digital cellular
handsets and wireless data modems. The integrated solution eliminates the IF SAW filter, external
low noise amplifier (LNAs) for three bands, transmit and RF voltage controlled oscillator(VCO
modules, and other discrete components found in conventional designs.
Figure 3-1 RECEIVER FUNCTIONAL BLOCK DIAGRAM
HCTIWSANNETNA
TCXO

3. TECHNICAL BRIEF
- 14 -
(1) Receiver Part
The Aero I transceiver uses a low-IF receiver architecture which allows for the on chip integration
of the channel selection filters, eliminating the external RF imagereject filters and the IF SAW
filter required in conventional super-heterodyne architectures.
A. RF front end
RF front end consists of Front End Module(FL500) and Quad band LNAs integrated in
transceiver (U500).
The Received RF signals(GSM 925MHz ~ 960MHz, DCS 1805MHz ~ 1880MHzPCS
1930MHz ~ 1990MHz) are fed into the antenna or Mobile switch. The Front End
Module(FL500) is used to control the Rx and Tx paths. And, the input signals VC1, VC2,
VC3 of a FL501 are directly connected to baseband controller to switch either Tx or Rx path
on.
The logic and current is given below Table 3-1.
Three differential-input LNAs are integrated in SI4205. The GSM input supports the
GSM850 (869-849 MHz) or E-GSM 900 (925-960MHz) bands. The DCS input supports
theDCS 1800 (1805-1880 MHz) band. The PCS input supports the PCS 1900 (1930-
1990MHz) band.
The LNA inputs are matched to the 150Ω balanced output SAW filters through external LC
matching networks. The LNA gain is controlled with the LNAG[1:0] and LNAC[1:0] bits in
register 05h (Figure 3-2).
Table 3-1 THE LOGIC AND CURRENT
VC1 VC2 VC3
DCS, PCS Tx
GSM / DCS Rx
PCS / DCS Rx
GSM Tx 0 V
0 V
0 V
2.5 ~ 3.0 V
0 V
0 V
0 V
2.5 ~ 3.0 V
0 V
0 V
0 V
2.5 ~ 3.0 V

3. TECHNICAL BRIEF
- 15 -
Figure 3-2 SI4205 RECEIVER PART
B. Intermediate frequency (IF) and Demodulation
Aquadrature image-reject mixer downconvertsthe RF signal to a 100KHz intermediate
frequency (IF) with the RFLO from the frequency synthesizer. The RFLO frequency is
between 1737.8 to 1989.9 MHz, and is internally divided by 2 for GSM 850 and E-GSM 900
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 (Figure3-2). The quadrature IF
signal is digitized with high resolution A/D converters (ADCs).
The ADC output is downconverted to baseband with a digital 100KHz quadrature LO signal.
Digital decimation and IIR filters perform channel selection to remove blocking and
reference interference signals. The selectivity setting (CSEL=0) or a low selectivity setting
(CSEL=1). The low selectivity filter has a flatter group channelization filter is in the
baseband chip. After channel selection, the digital output is scaled with a 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 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. TECHNICAL BRIEF
- 16 -
(2) Transmitter Part
The transmit (Tx) section consists of an I/Q baseband upconverter, and offset phase-locked loop
(OPLL) and two output buffers that can drive external poweramplifiers (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 (1850-1910MHz) bands.
A. 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 in-phase (TXIP, TXIN) and quadrature(TXQP, TXQN) 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 and internally divided by 2 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. Therefore, the IF PLL must be programmed per channel in the E-GSM
900 band.
Figure 3-3 SI4205 TRANSMITTER PART
GSM PA
PA
RFOG
RFOG
DCS/PCS

3. TECHNICAL BRIEF
- 17 -
B. 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 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. The I and Q signals are automatically swapped when
switching bands. Additionally, the SWAP bit in register 03h can be used to manually
exchange the I and Qsignals.
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 (Figure 3-3), and should be set to the
recommended settings detailed in the register description.

3. TECHNICAL BRIEF
- 18 -
Figure 3-4 SI4205 FREQUENCY SYNTHESIZER PART
The Aero I transceiver 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:
The DIV2 bit in register 31h controls a programmable divider at the XIN pin to allow either a 13
or 26 MHz reference frequency. For receive mode, the RF1 PLL phase detector update rate ( )
should be programmed = 100 kHz for DCS 1800 or PCS 1900 bands, and = 200 kHz for
GSM 850 and E-GSM 900 bands. For transmit mode, the RF2 and IF PLL phase detector
update rates are always =200 kHz.
(3) Frequency Synthesizer

3. TECHNICAL BRIEF
- 19 -
3.2 Power Amplifier Module (RF3166, U501)
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
50Ω input and output terminals.
The device is designed for use as the final RF amplifier in GSM850, EGSM900, DCS and PCS
handheld digital cellular equipment and other applications in the 824MHz to 849MHz, 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 3-5 FUNCTIONAL BLOCK DIAGRAM
GSM
RFOUT
DCS/PCS
RFOUT
GND
VRAMP
GSM
RFIN
VBATT
BAND SELECT
TX ENABLE
DCS/PCS
RFIN 1
2
3
4
5
6
78
9