Download lst260b service manual

CDMA Fixed Wireless Telephone
Service Manual
MODEL : LST-260B
LG Electronics Inc.
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
REVISED HISTORY
ISSUE
DATE
ISSUE 1.0
2005.09.28
CONTENTS OF CHANGES
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REMARK
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
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LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
Table of Contents
1. System Overview ............................................................................................................................................6
2. Circuit Description ...........................................................................................................................................7
2.1 RF Transmit / Receive Unit...........................................................................................................................7
2.2 Receive Unit Circuit ......................................................................................................................................7
2.2.1 Duplexer Filter............................................................................................................................................7
2.2.2 BASE BAND Unit .......................................................................................................................................7
2.2.3 Analog / Digital Conversion Circuit (ADC) .................................................................................................7
2.3 Transmit Circuit Unit .....................................................................................................................................8
2.3.1 Modulation and Automatic Gain Control Circuit .........................................................................................8
2.3.2 TX Band-pass Filter ...................................................................................................................................8
2.3.3 Power Amplifier ..........................................................................................................................................8
2.3.4 Voltage Controlled - Temperature Compensated X-tal Oscillator .............................................................8
2.4 Digital / Voice Processing Unit ......................................................................................................................9
2.4.1 Overview ....................................................................................................................................................9
2.4.2 Voice Processing Unit ................................................................................................................................9
2.4.3 MSM Unit ( MSM6025 ) .............................................................................................................................9
2.4.4 Memory Unit.............................................................................................................................................10
2.4.5 EVRC Function ........................................................................................................................................10
2.5 Network Interface Unit (NIU).......................................................................................................................10
2.5.1 Overview ..................................................................................................................................................10
2.5.2 Wireline Interface Circuit .........................................................................................................................10
2.5.3 DTMF Receiver Unit ................................................................................................................................10
2.5.4 Data Communication Unit ........................................................................................................................10
2.5.5 LED Display Unit ......................................................................................................................................11
2.6 FAX Module Circuit .....................................................................................................................................11
2.6.1 Overview ..................................................................................................................................................11
2.6.2 Facsimile Controller (XFC) ......................................................................................................................11
2.7 Power Supply Unit.......................................................................................................................................12
2.8 Battery Charging .........................................................................................................................................13
3. Programming ................................................................................................................................................13
3.1 Installation ...................................................................................................................................................13
3.1.1 How to Install ...........................................................................................................................................13
3.1.2 Available Tones .......................................................................................................................................13
3.2 Programming Instruction (via Telephone) ..................................................................................................13
3.2.1 Entering Main Programming Mode ..........................................................................................................14
3.2.2 Selecting the Sub-program Mode ............................................................................................................14
3.2.3 Changing the SPC (Service Program Code) ...........................................................................................14
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LST-260B Service Manual
3.3 NAM (Number Assignment Module) Programming ....................................................................................14
3.3.1 Entering NAM Number .............................................................................................................................14
3.3.2 Entering Slot Cycle Index .........................................................................................................................15
3.3.3 Entering Telephone Number ....................................................................................................................15
3.3.4 Entering MCC (Mobile Country Code) .....................................................................................................15
3.3.5 Entering MNC (Mobile Network Code) ....................................................................................................15
3.3.6 Entering SID, NID ....................................................................................................................................16
3.3.7 Entering channel ......................................................................................................................................16
3.3.8 Selecting the Vocoder ..............................................................................................................................16
3.3.9 Setting the Hook-Flash Time ...................................................................................................................16
3.3.10 Selecting Caller ID Mode .......................................................................................................................17
3.3.11 Selecting Dial Tone Level Index ............................................................................................................17
3.3.12 Selecting Busy (or Congestion) Tone Level Index .................................................................................17
3.3.13 Changing Tx Audio Level .......................................................................................................................18
3.3.14 Selecting Auto Dial Time .......................................................................................................................18
3.3.15 Entering VM Alert Ring ON/OFF ............................................................................................................18
3.3.16 Changing DTMF only mode ...................................................................................................................19
3.3.17 Clearing Lock Code ...............................................................................................................................19
3.3.18 Fax Module S/W Version .......................................................................................................................19
3.4 Test Call ......................................................................................................................................................19
3.4.1 Test Call Mode .........................................................................................................................................19
3.4.2 NV Clear Mode ........................................................................................................................................20
3.5. User Programming the Authentication Key................................................................................................20
3.6. Table for NAM Parameter Programming & Test Call ................................................................................21
3.6.1 Table for NAM Parameter Programming .................................................................................................21
3.6.2 Table for Test Call ...................................................................................................................................22
3.7. FCC TEST Menu .......................................................................................................................................22
4. Product Specification ....................................................................................................................................22
4.1 General Specification ..................................................................................................................................22
4.2 Receive Specification..................................................................................................................................23
4.3 Transmit Specification ................................................................................................................................24
4.4 Frequency Requirements ...........................................................................................................................25
4.5 Charge time ................................................................................................................................................25
4.5.1 Standard Battery ......................................................................................................................................25
4.6 Telephony Specification ..............................................................................................................................25
4.7 Functions of Major Semi-Conductors .........................................................................................................25
5. Trouble Shooting...........................................................................................................................................26
5.1 When Rx Carrier is not normal. ..................................................................................................................26
5.2 When Rx parts do not work ........................................................................................................................27
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LST-260B Service Manual
5.3 When Tx parts do not work.........................................................................................................................28
5.4 When Power is not “Turn On”. ....................................................................................................................29
5.5 When LED do not display. ..........................................................................................................................31
5.6 When Rx Audio is not transmitted. .............................................................................................................32
5.7 When TX Audio is not transmitted. .............................................................................................................33
5.8 When DTMF Signal is not detected. ...........................................................................................................34
5.9 When G3 FAX is not transmitted. ...............................................................................................................35
5.10 When G3 FAX is not received. .................................................................................................................37
6. Block Diagram ..............................................................................................................................................39
6.1 RF Block Diagram .......................................................................................................................................39
6.2 Base Band Block Diagram ..........................................................................................................................40
6.3 Fax Module Block Diagram .........................................................................................................................41
7. Exploded View ..............................................................................................................................................42
8. PCB Drawing ................................................................................................................................................43
8.1 MAIN PCB(LST-260) ..................................................................................................................................43
8.2 LST-255 / LST260 FAX Module PCB .........................................................................................................43
9. Circuit Diagram .............................................................................................................................................43
9.1 LST-260 MAIN ............................................................................................................................................43
9.2 LST-260 RF ................................................................................................................................................43
9.3 LST-255 / LST-260 FAX Module ................................................................................................................43
10. Replacement Parts List...............................................................................................................................43
10.1 BOM LST-260 ...........................................................................................................................................43
10.2 BOM LST-255 / LST-260 FAX Module .....................................................................................................43
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LST-260B Service Manual
1. System Overview
With the WLL system, a switching system can controls a number of BTS automatically by setting up data
transmission lines with them. WLL system allows BTSs located certain distances from each other to reuse
frequency by utilizing the frequency allocation technique in consideration of interference for the cell sites
with low level of output.
Code Division Multiple Access (CDMA) based on digital cellular technology operates under the interference
limit environment not the band limit of Time Division Multiple Access (TDMA) and Frequency Division
Multiple Access (FDMA), and is superior to the other two mechanisms in terms of subscriber capacity.
TDMA can accommodate three times more subscribers than FDMA and CDMA exceeds FDMA by 12 to
15 times.
CDMA technology can be explained as follows: If two persons want to speak at the same time, they can
take turns with one person speaking at the time or two rooms can be provided one to each. The first
approach is TDMA and the second one is Space Division Multiple Access (SDMA). Or for example two
persons sing at the same time, one in soprano and the other one in base tone, and the audience have a
device filtering only the tone that they want to hear. This is CDMA approach. With the technology, no
matter how many singers sing a song or how many languages are spoken at the same time, the audience
can filter what they want to without being confused as long as they are in different tones and in different
languages.
In CDMA, each signal has unique pseudo random binary sequence which is used to spread spectrum of
carriers. Multiple of CDMA signals share a frequency spectrum on which they are displayed being
overlapped with each other. Coherent detector selectively receives the signal energy with matching pseudo
random binary sequence and restores the spectrum. Signals with mismatching codes are considered
inferences as the spectrum are not restored and are processed as noises.
The LST-260 WLL phone applies DS(Direct Sequence)-CDMA mode. CDMA network consists of
MSC(Mobile Switching Centers), BSC(Base Station Controllers), BTS(Base Station Transmission
Systems), and MS(Mobile Stations), Communication between MS and BTS is designed to meet the
specification of Common Air Interface. MS meets the specifications below.
-
IS-95C (Common Air Interface) : Protocol between MS and BTS
-
TIA/EIA/IS-98-D : Minimum Performance Requirements for MS
-
TIA/EIA/IS-96 : CDMA Voice Coder Standards
-
TIA/EIA/IS-707A-1 : CDMA Data Services Revision for cdma2000 Rel.0
-
TIA/EIA/IS-637-A : Short Message Services for Wide-band Spread Spectrum Systems
-
TIA/EIA/IS-683A : OTA Service Provisioning of Mobile Stations in Wide-band Spread Spectrum
Systems
-
TIA/EIA/IS-127 : Speech Service Option Standard for EVRC(8Kbps)
-
TIA/EIA/IS-126-A : Loop-back Service Options Standard for Wide-band Spread Spectrum Fixed
Wireless Telephone
-
TR45.0.A/TSB-50 : User Interface for Authentication Key Entry
-
TIA/EIA/IS-2000 PN-4756(Ballot Resolution Version) : Addendum 1(IS-2000 Standard)
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2. Circuit Description
2.1 RF Transmit / Receive Unit
The transmit/receive unit is designed with zero intermediate frequency method. The unit uses the transmit
frequency of 824~849 MHz and the receive frequency of 864~894MHz.
The RF signal received via an antenna is fed into a down converter after it passes through a duplex filter
and a low noise amplifier (LNA). RF signal passes through a band pass filter (BPF) and undesired signals
are removed. Then the frequency is converted into a base-band signal via an auto-gain control amp (AGC
AMP) in RFR6122. The functions of the RFR6122 include the RF VCO, RX AGC amplifier, quadrate RF
mixers, down-conversion from RF to analog base-band, low-pass filters for converting to digital base-band
signal. Finally, this digital base-band signal is demodulated by MSM6025.
For transmit signal, the signal is digitized, modulated, interpolated, and converted the digital signal into an
analog base band signal by MSM6025 before sending it to the RFT6122. The MSM6025 communicates
with the external RF and analog base-band signal to control signal gain in the RF RX and TX signal paths,
reduce base-band offset errors, and tune the system frequency reference. The RFT6122 is Base band-toRF Transmit Processor and performs all transmit signal processing functions required between digital base
band and the Power Amplifier. The up-converted RF signal is amplified by the Power Amplifier and finally,
sent to the cell site via the antenna after going through duplexer.
2.2 Receive Unit Circuit
2.2.1 Duplexer Filter
The duplexer is operated in a full duplex mode by using a TX/RX antenna. For this purpose, the duplexer
is made up of an RX band pass filter and a TX band pass filter. The TX band pass filter suppresses noises
and spurious emissions in outside band when the TX unit transmits the signal. The RX band pass filter is
used to remove the outside band spurious signals when it receives data signal. In addition, it prevents
transmitting signal that enters RX input port, in order to improve RX sensitivity characteristics.
During the RX/TX signals are going through the duplexer, the insertion loss in TX band should not exceeds
3.5 dB and that of RX band should not exceeds 4.0dB. The attenuation of the RX band to TX band pass
filter should be at least 40dB. It should be at least 30dB at the 1648~1698MHz. In addition, the attenuation
of the TX band to RX band pass filter should be at least 55dB or more.
2.2.2 BASE BAND Unit
The RF signal are amplified by LNA within the RFR6122 then pass through band pass filters before being
applied to the RFR6122 Receiver IC. All receive signals are down converted directly from RF to base-band
within the Receiver IC. Down converter LOs are generated using the RFT6122 RX phase-locked loop
(PLL) and RFR6122 VCO. The RFR6122 IC provides the Zero-IF receiver signal path for Cellular-CDMA
reception. The RF signal paths include MSM controlled gain adjustments. The amplifier outputs drive the
RF ports of the quadrate RF-to-base-band down-converters. The down-converted base-band outputs are
multiplexed and routed to low pass filters (one I and one Q) whose pass band and stop band
characteristics are mode dependent. The filter outputs are buffered and routed to the MSM device for
further processing.
2.2.3 Analog / Digital Conversion Circuit (ADC)
The RF signal from the RX AGC Amplifier is separated into I-channel and Q-channel base band
components and down-converted by mixing with quadrate local oscillator signals. Local oscillator signals
are generated by a voltage-controlled oscillator (VCO) within the RFR6122 and phase lock loop (PLL)
within the RFT6122. The I/Q down converter outputs the CDMA signals at the base band frequency that
extends from 1kHz to 630kHz. Low-pass filtering enables the receiver to select the desired base band
signals from the effects of unwanted noise or adjacent-channel interference. The I/Q Offset, which is
derived by MSM6025 via RC filters, adjusts the levels of ADC’s input signal so that outputs of ADC midscale over all valid operating conditions. CDMA analog base band Q signals and I that have been tuned up
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LST-260B Service Manual
are converted to digital signals by two identical 4-bit ADCs. The CDMA ADC’s output a new 4-bit parallel
digital value on each rising edge of the ADC’s synchronous clock input signal, CHIPx8. The CHIPx8 ADC
clock frequency of 9.8304 MHz is developed in the MSM6025 by multiplying the 19.2MHz system crystal
oscillator frequency by 512/1025.
2.3 Transmit Circuit Unit
2.3.1 Modulation and Automatic Gain Control Circuit
The RFT6122 IC provides the Zero-IF transmitter signal path, from analog base-band to RF driver
amplifiers. The MSM device provides I and Q differential base-band signals (CDMA); these analog input
signals are amplified and applied to the up-converter mixers. For this chipset, Cellular-CDMA refers to
band classes 0 and 3 as defined by the cdma2000 standard, with mobile station transmitters operating
between 824 and 849 MHz. The transmit signal path includes base-band amplifiers, quadrature upconversion, gain control RF amplification, and an output driver amplifier. The RFT6122 IC includes
transmit DACs, two phase-locked loop circuits (TX LO for RFT6122 and RX LO for RFR6122), the TX
VCO circuit, TX LO generation and distribution circuits, and various interface, control, and status circuits.
The I, Q base-band analog signals which come from the MSM6025 is up-converted by Mixer within
RFT6122. This Mixer is connected to PLL and VCO block. TX_AGC_ADJ, which is the signal for TX power
control from MSM6025 changes into DC after going through R and C filters.The amplified RF signal from
AGC amplifier is filtered by SAW filter. Specification of Conducted Spurious Emission and a band pass
filter (saw) to cut off the spurious signals being outside of band.
2.3.2 TX Band-pass Filter
Transmitting signals that come from RFT6122 is fed to RF Band Pass Filters in order to remove the
outside band spurious signal during the amplification of RF signals. Insertion Loss of these RF BPF is 3 dB
as a maximum, whereas the ripple in the pass band is 1.5 dB as a maximum. The degree of the
suppression of transmitting signals on receive band is at least 25 dB or more. The maximum power that
can be inputted is about 25 dBm.
2.3.3 Power Amplifier
The transmitting signal that passed the transmitting band-pass filter is sent to the BTS via power amp,
isolator , duplex filter, and antenna sequentially. And the unit is designed so that the final antenna output
power should be about 250mW. In addition, for the activation of power amp, 3.8V should be fed into Drain.
The power amplifier that can be used in the CDMA mode has linear amplification capability and it has a
high efficiency. For higher efficiency, it is made up of one MMIC (Monolithic Microwave Integrated Circuit)
for which RF input terminal and internal interface circuits are integrated onto one IC after going through the
AlGaAs/GaAs HBT (Heterojunction Bipolar Transistor) process. The module of power amplifier is made up
of an output end interface circuit including this MMIC. The maximum power that can be inputted through
the input terminal is +6 dBm and conversion gain is about 28 dB. RF transmitting signals that have been
amplified through the power amplifier are sent to the duplexer and then, sent out the cell site through the
antenna in order to prevent any damages on circuits, that may be generated by output signals reflected
from the duplexer and re-inputted to the power amplifier output end. The maximum power can be inputted
is 1W and Insertion Loss is about 0.7dB. Input/output separation is at least 15 dB or greater(18dB or
greater during the normal operating temperature).
2.3.4 Voltage Controlled - Temperature Compensated X-tal Oscillator
The temperature range that can be compensated by VC-TCXO which is the reference frequency generator
of WLL terminal is -30C ~ +80C. VC-TCXO receives frequency tuning signals called TRK_LO_ADJ from
MSM as 0.5V~2.5V DC via R and C filters generates the reference frequency of 19.2 MHz and input it into
the frequency synthesizer of UHF band. Frequency stability depending on temperature is  2.0 ppm
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2.4 Digital / Voice Processing Unit
2.4.1 Overview
The Digital / Voice Processing Unit processes user command and processes all the digital and voice signals.
The digital / Voice processing unit is composed of Voice Processing unit, Mobile Station Modem (MSM),
Memory unit, EVRC function.
2.4.2 Voice Processing Unit
The signal from the NIU is amplified at the audio amp, inputted into the audio processor (CODEC), and
converted into a digital signal. Then, it is transmitted into the vocoder. In addition, the digital audio signal
coming from vocoder is converted into an analog signal via the CODEC and is transmitted to the NIU via an
amp.
2.4.3 MSM Unit ( MSM6025 )
Qualcomm’s 3G CDMA Multi-carrier 1xMC solutions, the MSM6025 is designed to the IS-2000 standard and
enables up to a doubling of overall IS-95A/B voice capacity and new higher data rate services. Featuring
support for Quick Paging Channel, the MSM6025 provides an increase in handset standby time of up to 50
percent over IS-95A/B handsets. The main Clock for MSM6025 is TCXO and buffered by a 2.7V inverter
and inputted to the MSM. TCXO is the primary clock source used by various blocks of MSM6025, such as the
ARM7TDMI ringer, UARTs, general purpose PDMs. TCXO can be used as a vocoder clock source for EVRC
support. TCXO is also used to produce CHIPX8. When the system is in sleep mode the TCXO clock is not
used. Instead 32.768 KHz Sleep Crystal is used for power saving. On initial power up, _RESET must be of
sufficient duration for the external VC-TCXO, which is the source of TCXO signal to stabilize. This is true for
the watchdog timeout duration. In non-sleep mode, the microprocessor must reset the watchdog timer at
least once every 213ms.
Otherwise the watchdog timer expires and asserts _RESET signal to the system.
MSM unit is composed of an ARM7TDMI CPU, UART, RF interface, GPADCs, SBI
(Serial Bus Interface) controller, CODEC, Encoder, Interleaver, De-Interleaver, Viterbi Decoder,
Mod/Demodulator, and Vocoder. It performs most of control functions in the terminal.
An ARM7TDMI series CPU controls the terminal operation. It controls most of the functionality for the Mobile
Station Modem including control of the external peripherals such as the keypad, and memory devices through
the system software. Through a generic Serial Bus Interface (SBI) the ARM7TDMI configures and controls
the functionality of the RFT6122.
The UART communicates with serial data that conforms to RS-232 interface protocol.
It is used as a serial data port in Mobile Station testing and debugging system with user-defined download
program. To realize the fast 153.6 kbps data rates, primary UART has been enhanced to increase throughput
up to 230.4kbps by supporting double clock speed and increasing the FIFO depths (both RX and TX). The
double clocking UART can be used to support MSM6025 data rates. However its primary intend is to support
test and development.
RF Interface communicates with the Mobile Station’s external RF and analog base-band circuits. Signals to
these circuits control signal gain in the RX and TX signal path, control DC. Base-band offset errors, and
maintain the system’s frequency reference.
It controls RF control signals for precise Power control. MSM6025 estimate the power spectral density within
1.2288MHz bandwidth of the frequency channel used for CDMA demodulation. The control signals are PDM
(Pulse Density Modulation) signals, which is RC, filtered and converted to DC levels to control RF paths.
The GPADCs are intended to digitize DC signals corresponding to analog parameters such as battery
voltage, temperature and RF power levels. MSM6025 has 7 analog input pins, which are multiplexed to the
input of the internal GPADC.
The Serial Bus Interface is specifically designed to be a quick, low pin count control protocol for Qualcomm’s
RFT6122 ASICs. Using Serial Bus Interface, the RFT6122 can be configured for different operating modes
and configured for minimum power consumption, extending battery life in standby mode.
MSM6025 integrates an audio voice band Codec into Mobile Station Modem. The integrated Codec contains
all of the required conversion and amplification stages for the audio front end.
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The signal from the NIU is amplified at the stage 1, stage 2(external High-Pass Filter) of the audio amp. And
then it is inputted into the audio processor (CODEC), and converted into a digital signal by Analog to Digital
Converter. And then, High-Pass-filter, Slope filter, FIR Filter are used to compensate for a required
receiving/transmitting path gain, frequency response. The codec operates as a 13-bit linear Codec with the
Transmit (TX) and Receive (RX) filters designed to meet ITU-T G.712 requirements. The codec includes a
programmed side tone path for summing a portion of the TX audio into RX path. High-Pass-Filter, Slope
Filter.
The codec is configured through the QDSP4000 Command types and is not directly controlled by the
microprocessor.
The input digital voice data becomes variable rate after being voice encoded. In addition, it is convolutional
encoded for error detection and correction. Coded symbols are interleaved against multi-path fading. Each
data channel is scrambled by the long code PN sequence of user in order to ensure call confidentiality. Binary
orthogonal switching codes based on the Walsh function is used for the classification of each channel. Data
created as the above are 4 phases converted by one pair of pilot PN code and I, Q data is created. Then, it is
sent to B/B AISC for transmission. When I, Q data is received, it is demodulated as symbol in the
demodulator and de-interleaved. After the Viterbi decoder detects and corrects the errors of data received,
the vocoder performs voice decoding on the data to convert it into digital voice data.
2.4.4 Memory Unit
This unit is composed of two units. One is a flash memory for storing a main program activating MSM, user
service related data and RF calibration. Another is SRAM for reading and writing data.
2.4.5 EVRC Function
Enhanced Variable Rate Code (EVRC) phone is an upgraded CDMA phone to provide high-quality voice
service. EVRC phone has better voice quality than QCELP phone used by the existing CDMA mobile
communication service provider. In case the EVRC system is not supported due to bad conditions of BTS,
QCELP method can be used instead. EVRC phone has the function of reducing surrounding noise and
accordingly, enables the user to make calls in a clear voice state even in a noise place. EVRC phone can
support the protocol of existing IS-95 and IS-95A mode. It can also support a new protocol TSB-74
specification.
2.5 Network Interface Unit (NIU)
2.5.1 Overview
The Network Interface Unit(NIU) provides analog interfaces between the Single Line Telephone (SLT) and
system. SLT interface circuit of NIU Provides 48volt DC feed to the SLT and Ring signal to the SLT. The
SLT interface supports both pulse and DTMF dialing from the SLT and provides the A/D and D/A
conversions for audio and signaling path to and from the G3 Analog FAX Module. This unit receives PC
data into MSM unit through a RS-232C or a USB port and transmits the data received via RF. Reversely, it
receives radio data into MSM unit and sends it to PC.
2.5.2 Wireline Interface Circuit
SLT or G3 FAX machine can be connected to the NIU through the terminal RJ11 of NIU Board. The line
protection circuitry consists of 1 surge absorber and fuse between Tip and Ring. The wireline circuit
provide impedance matching and off hook sense from the SLT(or FAX machine) line to the NIU.
2.5.3 DTMF Receiver Unit
The DTMF Receiver provides the ability to monitor and identify externally Dual Tone Multiple Frequency.
This supports program function and DTMF dialing via Tip & Ring lines to DTMF Receiver on NIU.
2.5.4 Data Communication Unit
This unit receives PC data into MSM unit through a RS-232C(using RJ-45 connector) or a USB port and
transmits the data received via RF. The other way, it receives radio data into MSM unit and sends it to PC.
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2.5.5 LED Display Unit
The LED is used to display the information on the current terminal status. The LED unit displays the RSSI
status, battery status, voice mail and FAX status.
2.6 FAX Module Circuit
2.6.1 Overview
The FAX Module Hardware consists of the Conexant Facsimile Engine (CX06835-16) device.
2.6.2 Facsimile Controller (XFC)
The CX06835-16 contains an internal 8 bit microprocessor with a 16M byte address space, an internal
ML94 DSP fax modem DSP core, an internal fax modem codec (or integrated analog circuit), and
dedicated circuitry optimized for facsimile image processing and facsimile machine control and monitoring.
The microprocessor is an enhanced MC24 central processing unit (CPU). This CPU provides fax
instruction execution and memory efficient input/ouput bit manipulation. The MC24 CPU runs at a clock
rate of up to 10 MHz and derives it timing from the fax modem DSP clock. The CPU connects to other
internal CX06835-16 functions over an internal 8-bit data and 24-bit address bus dedicated control lines.
Various Chip Selects (CS) are provided by the CX06835-16 such as ROMCS* for program FLASH
MEMORY, RAMCS* for external SRAM.
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2.7 Power Supply Unit
The power supply unit receives 12V power from the AC adapter and sends out 1.85V, 2.7V, 3.0V, 3.8V, 3.8V and -48V output via a voltage regulator. During this time, 3.8V output is used to activate the power
amp of RF transmit/receive unit and Data Communication. The unit supplies 3.8V output to the Telephone
Interface units, and 3.8V output supplies 3.0V to the digital units, 3.0V to the MSM(MSMP), 1.85V to the
MSM(MSMC) and 2.6V to the MSM(MSMA). The -48V is used feeding voltage at Tel line. The power
supply unit also supplies required power to various power lines via a voltage regulator.
Following is a power configuration diagram of LST-260B.
◆ Ring GEN.
U30
-48V
+12V DC
From Adaptor
◆ NIU Circuit
◆ PAM
U31
+3.8V
◆ NIU Circuit
U11
U22
+2.6V
◆ MSM6025(MSMA)
◆ MSM6025(MSMP)
+3V
◆ Digital Logic Circuit
◆ MSM6025(MSMC)
U12
+1.85
◆ Digital Logic Circuit
V
U19
U15
-3.8V
+2.6V
U2
+2.6V
Figure 2-1. LST-260B Power Configuration Diagram
12
◆ NIU Circuit
◆ RF RX Circuit
◆ RF TX Circuit
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
2.8 Battery Charging
When the external power is not available, LST-260B can use the internal back-up battery. Before that,
battery must be charged. LST-260B offer both the normal charging and trickle charging (maintenance
charging). The normal charging is feeding about 300mA and the trickle charging is feeding about 60mA.
The normal charging operates, if only both external power and battery mode is applied. The trickle
charging is operates, when the normal charging is operated for over-6hours, or battery temperature is
overheat for over-chargnig.
3. Programming
Following pages contains the programming instructions for LST-260B model. LST-260B supports 800MHz
CDMA Digital mode Master Access Commands and CDMA Programming.
The following commands require that the field service code is used to enter the programming mode.
3.1 Installation
3.1.1 How to Install
① Connect the dipole antenna or high-gain antenna which is provided optionally by LGE to the
TNC antenna port.
② Connect your telephone device to LST-260B with a RJ-11 cable to the port marked as “Phone”.
③ Plug a DC power cable that is attached to the power supply into the DC power connector on the
top of your terminal .
④ Plug the male end of the AC power cord into an AC wall outlet.
⑤ Then Power LED turns into Green color (If the battery pack is inserted into the battery pack
house in the bottom of the terminal, the Power LED turns into Green. And if the capacity of
battery downs under certain level, the LED turns into Amber.)
⑥ Please check Signal LED is Green color (Good signal reception) before making or receiving a
call.
Note :
① For a data service and/or PC fax service, connect your PC with RS-232 cable which is provided
optionally to DB-9 port of LST-260B.
② Because LST-260B supports two RJ-11 ports, and both ports are regarded as same port, you don’t need
to concern on telephone line configuration. Typically, for G3 analog Fax service, connect your Fax with
RJ-11 cable to the port marked as “Fax”
3.1.2 Available Tones
① Service Change Tone : “Bee-beek” sound can be heard when you enter the service
programming mode, in other words, after entering ‘#’, ‘#’, ‘0’ key sequence in off-hook state.
② Confirmation Tone : “Doo-doo” sound can be heard when you enter a value correctly in the
menu mode.
③ Error Tone : “Beek-” sound can be heard when you enter a value illegally in the menu mode.
3.2 Programming Instruction (via Telephone)
If you do not have DM(Diagnostic Monitor) Program or PST (Product Support Tool) program which is to be
provided by LGE, you can program or change some NAM (Number Assignment Module) parameters with
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ordinary telephone device, which is referred to as a POTS(Plain Old Telephone Set) phone. This
programming mode is not accessible while in a call.
3.2.1 Entering Main Programming Mode
Procedure : ‘#’ + ‘#’ + ‘0’ + SPC (Service Program Code)
① SPC is used to enter into the NAM programming mode. SPC (Service Program Code) is
composed of 6 digits number and the default value is “000000”.
② If you enter wrong SPC value, you can hear the error tone from LST-260B via your telephone
handset.
③ If correct SPC value is entered, LST-260B is to be off-line state. Then you can enter into the
mode for setting the NAM parameters and test call mode.
④ If the hook switch is pressed down in the middle of entering the SPC value, LST-260B is to
return to idle state.
3.2.2 Selecting the Sub-program Mode
Procedure : ‘#’ + ‘1’(NAM-system setting mode) or ‘2’ ( test call mode )
in Main Program Mode
① You can select the one of two sub-program mode in the main program mode. Those are NAMsystem setting mode and test call mode.
② If you press digit ‘1’, you will hear the confirmation tone and enter NAM-system programming
mode,
③ If you press digit ‘2’, you will hear the confirmation tone and enter test call mode.
3.2.3 Changing the SPC (Service Program Code)
Procedure : ‘#’ + ‘0’ + ‘#’ + New SPC + ‘#’ + New SPC + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② If you want to change SPC, you have to enter the new SPC two times for confirmation.
③ After entering first new SPC value you want to change to, you should enter same SPC value
again for confirmation.
④ If the second new SPC value does not match with the first one, LST-260B will return to the
initial stage with the error tone.
3.3 NAM (Number Assignment Module) Programming
When the sequence for each NAM parameter is ended and if the entered value is accepted, then, the
confirmation tone is heard and the change will be stored. In case of a rejected value, you can hear the
error tone and the currently stored value is retained. Going on-hook will exit the programming mode.
3.3.1 Entering NAM Number
Procedure : ‘#’ + ‘1’ + ‘#’ + NAM number + ‘’
(Default “O”
(in NAM-system setting mode)
① Entering NAM-system programming mode.
② NAM number is in range of 0 to 1.
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③ If the NAM number is not in the range of 0 to 1, it is considered invalid and you will hear error
tone and you can enter NAM number again.
④ If the number is in range, you will confirmation tone and FWT will reset.
3.3.2 Entering Slot Cycle Index
Procedure : ‘#’ + ‘2’ + ‘#’ + Slot Cycle Index + ‘’
(in NAM-system setting mode)
① Entering NAM-system programming mode.
② Slot cycle index is in range of 0 to 7 and default value is 2.
③ If the Slot Cycle Index is not in the range of 0 to 7, it is considered invalid and you will hear
error tone and you can enter slot cycle index number again.
④ If the number is in range, you will hear confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18. (except 3.3.7)
3.3.3 Entering Telephone Number
Procedure : ‘#’ + ‘3’ + ‘#’ + Telephone number + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② Phone number is composed of 10 digits or less.
③ If the number is in range, you will hear the confirmation tone and you can try to change the
NAM parameter according to the procedure between the clause 3.3.1 to clause 3.3.18. (except
3.3.7)
3.3.4 Entering MCC (Mobile Country Code)
Procedure : ‘#’ + ‘4’ + ‘#’ + MCC + ‘’ (Default 404)
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② MCC code is composed of 3 digits.
③ If MCC code entered is longer than 3 digits, it is considered invalid and you will hear the error
tone and you can enter MCC code again.
④ In case of entering the code shorter than 3 digits, the code is padded with ‘0’ to the low position.
ex) Entering 2 results in 200. Entering 20 results in 200.
If you want to result 2, enter 002. And if you want to result 20, enter 020.
⑤ If the code is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18. (except 3.3.7)
3.3.5 Entering MNC (Mobile Network Code)
Procedure : ‘#’ + ‘5’ + ‘#’ + MNC + ‘’ (Default 00)
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② MNC code is composed of 2 digits.
③ If MNC code entered is longer than 2 digits, it is considered invalid and you will hear the error
tone and you can enter MCC code again.
④ In case of entering the code shorter than 2 digits, the code is padded with ‘0’ to the low position.
ex) Entering 2 results in 20.
If you want to result 2, enter 02.
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⑤ If the code is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18. (except 3.3.7)
3.3.6 Entering SID, NID
Procedure : ‘#’ + ‘6’ +‘#’ + [SID] + ‘#’ + [NID] + ‘’
(in NAM-system setting mode)
①
②
③
④
Enter NAM-system programming mode.
The selectable SID is in range of 0 to 32767
The selectable NID is in range of 0 to 65535
If the SID or NID is not in range, it is considered invalid and you will hear the error tone and
you can enter the SID or NID again.
⑤ If the NID is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18 (except 3.3.7)
3.3.7 Entering channel
Procedure : ‘#’ + ‘7’ +‘#’ + [channel] + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The selectable range of channel is from 1 to 1023 in DCN, from 25 to 1175 in PCS.
③ If the channel is not in range, it is considered invalid and you will hear the error tone and you
can enter the channel again.
④ If the channel is in range, you will hear the confirmation tone and you can try to change the
NAM parameter according to the procedure between the clause 3.3.1 to clause 3.3.18
⑤ If you push ‘#’ after channel, you can enter channel again. This procedure allows until 31st
channel input. In this case, you should push ‘’ after inputting 31st channel.
3.3.8 Selecting the Vocoder
Procedure : ‘#’ + ‘8’ + ‘#’ + [VOCODER number] + ‘’ (Default EVRC)
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The vocoder number is in range of 1 to 2.
③ If the vocoder number is not in range, it is considered invalid and you will hear the error tone
and you can enter the vocoder number again.
④ If the number is in range, you will hear confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18. (except 3.3.7)
⑤ Refer to following table
Number
Vocoder
1
2
EVRC
13K QCELP ( SO 32768 )
3.3.9 Setting the Hook-Flash Time
Procedure : ‘#’ + ‘9’ + ‘#’ + [Flash Time] + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
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② The Hook-Flash Time is in range of 20 to 200 and unit time is 5msec.
③ If the Hook-Flash Time is not in range, it is considered invalid and you will hear the error tone
and you can enter the Hook-Flash Time again.
④ If the Hook-Flash Time is in range, you will hear the confirmation tone and you can try to
change the NAM parameter according to the procedure between the clause 3.3.1 to clause
3.3.18. (except 3.3.7)
3.3.10 Selecting Caller ID Mode
Procedure : ‘#’ + ‘13’ + ‘#’ + [CID mode] + ‘’(Default DTMF mode 4)
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The Caller ID mode is in range of 1 to 4.
③ If the mode is not in range, it is considered invalid and you will hear the error tone and you can
enter the mode again.
④ If the mode is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
⑤ Refer to the following table
Caller ID number
Mode
1
2
Disable Caller ID feature
Bellcore FSK Mode.
3
4
China FSK Mode.
DTMF Mode
3.3.11 Selecting Dial Tone Level Index
Procedure : ‘#’ + ‘14’ + ‘#’ + [Dial Tone Level Index] + ‘’(Default Mid 2)
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The dial tone level index is in range of 1 to 3.
③ If the mode is not in range, it is considered invalid and you will hear the error tone and you can
enter the mode again.
④ If the mode is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
⑤ Refer to the following table
Index No.
Dial Tone Level
1
2
Low
Mid
3
High
3.3.12 Selecting Busy (or Congestion) Tone Level Index
Procedure : ‘#’ + ‘15’ + ‘#’ + [Busy(or Congestion) Tone Level Index] + ‘’(Default mid 2)
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(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The busy (or congestion) tone level index is in range of 1 to 3.
③ If the mode is not in range, it is considered invalid and you will hear the error tone and you can
enter the mode again.
④ If the mode is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
⑤ Refer to the following table
Index No.
Busy (or Congestion) Tone Level
1
Low
2
3
Mid
High
3.3.13 Changing Tx Audio Level
Procedure : ‘#’ + ‘16’ + ‘#’ + [Tx Audio Level] + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The selectable Tx Audio Level is in range of 0(Low) to 11(High).
③ If the Tx Audio level is not in range, it is considered invalid and you will hear the error tone and
you can enter the Tx Audio level again.
④ If the Tx Audio level is in range, you will hear the confirmation tone and you can try to change
the NAM parameter according to the procedure between the clause 3.3.1 to clause 3.3.18
3.3.14 Selecting Auto Dial Time
Procedure : ‘#’ + ‘17’ + ‘#’ + [Auto Dial Time] + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The auto dial time is in range of 2 to 9 (seconds).
③ If the time is not in range, it is considered invalid and you will hear the error tone and you can
enter the time again.
④ If the time is in range, you will hear the confirmation tone and you can try to change the NAM
parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
3.3.15 Entering VM Alert Ring ON/OFF
Procedure : ‘#’ + ‘18’ + ‘#’ + [VM Alert Ring ON/OFF] + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The selectable VM alert ring ON/OFF are 1(ON) and 2(OFF).
③ If the selection is not in range, it is considered invalid and you will hear the error tone and you
can enter the VM alert ring ON/OFF again.
④ If the selection is in range, you will hear the confirmation tone and you can try to change the
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NAM parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
3.3.16 Changing DTMF only mode
Procedure : ‘#’ + ‘19’ + ‘#’ + [DTMF only mode On/Off] + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The selectable DTMF only mode ON/OFF are 1(ON) and 2(OFF).
③ If the selection is not in range, it is considered invalid and you will hear the error tone and you
can enter the DTMF only mode ON/OFF again.
④ If the selection is in range, you will hear the confirmation tone and you can try to change the
NAM parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
3.3.17 Clearing Lock Code
Procedure : ‘#’ + ‘20’ + ‘#’ + ‘’
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② This menu has not any selection.
③ If the procedure is correct, you can try to change the NAM parameter according to the
procedure between the clause 3.3.1 to clause 3.3.18.
3.3.18 Fax Module S/W Version
Procedure : ‘#’ + ‘21’ + ‘#’ + [Version Number] + ‘’ (Default A-4 standard version 0
)
(in NAM-system setting mode)
① Enter NAM-system programming mode.
② The Fax Module version number is in range of 0 ~ 2 or 10.
③ If the version number is not proper, it is considered invalid and you will hear the error tone and
you can enter the mode again.
④ If the version number is proper, you will hear the confirmation tone and you can try to change
the NAM parameter according to the procedure between the clause 3.3.1 to clause 3.3.18.
⑤ Refer to the following table
Version number
Fax Module S/W Version
0
A.4 STANDARD Version
1
2
A.4 3COM Version
A.4 LG Version
10
A.7 STANDARD Version (Default Value)
3.4 Test Call
3.4.1 Test Call Mode
Procedure : ‘#’ + [Test Call number] + ‘’
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(in Main Program Mode )
① Enter test call mode.
② Refer to following Test Call table.
NUMBER
1
2
3
4
5
6
7
8
9
TEST CALL
Old 8K Markov
New 8K Markov
New 13K Markov
8K Loopback
13K Loopback
Markov SO54
Loopback SO55
Simple TDSO
Full TDSO
3.4.2 NV Clear Mode
Procedure : ‘#’ + 0 + ‘’ ’
(in Main Program Mode )
①
②
③
④
Enter test call mode.
Enter key ‘0’ and ‘’. Wait about 9 seconds and hook-on. The all NV area will be cleared.
After software downloading, if the terminal operate illegally, then use this function.
After NV Clear, every data stored in the terminal including the calibration data will be cleared.
So you MUST save the calibration data before executing this function.
3.5. User Programming the Authentication Key
Procedure : ‘2’, ‘5’, ‘3’, ‘9’, ‘*’, ‘*’, ‘#’, [A-key],[Check Sum Digits],‘*’
①
②
③
④
⑤
⑥
⑦
Lift the handset of single line telephone connected with WLL terminal.(Make off hook state)
To reach the authentication key programming mode, press ‘2’, ‘5’, ‘3’, ‘9’, ‘*’, ‘*’, ‘#’.
You can hear the service change tone if you reach the authentication key programming mode.
Press [A-key],[Check Sum Digits].
To save A-key, press ‘*’.
You can hear the confirmation tone if the A-key is saved.
Hang up the handset.(to go to the on-hook state)
 The error tone will be heard if the incorrect authentication key and check-sum digits are entered or
saved. In that case, retry with a correct authentication key and check-sum digits.
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3.6. Table for NAM Parameter Programming & Test Call
3.6.1 Table for NAM Parameter Programming
Description
Setting Procedure
 SPC(Service Program Code)
# 0 # [New SPC] # [New SPC] 
# # 0 [SPC]
+
#1
NAMsystem
Setting
Mode
Description
# # 0 [SPC]
+
#1
NAMsystem
Setting
Mode
 NAM Setting
# 1 # [NAM number] 
 Slot Cycle Index
# 2 # [Slot Cycle Index] 
 Telephone number
# 3 # [Telephone number] 
 MCC(Mobile Country Code)
# 4 # [MCC] 
 MNC(Mobile Network Code)
# 5 # [MNC] 
 SID NID # 6 # [SID] # [NID] 
Remarks
SPC is composed of 6 numeric
digits and the default value is set as
‘000000’
Reset after storing
 It returns to the idle state after
pressing ‘*’ key
 Pressing the hook switch at each
stage, it terminates the service
program and store.
 The SID/NID setting menu and
CDMA channel menu takes no
effect when PRL is activated via
WLL PST S/W.
 Channel # 7 # [Channel] 
 Select Vocoder # 8 # [Vocoder Number]

Setting Procedure
 Hook Flash Time Setting
# 9 # [Hook Flash Time] 
 Caller ID Mode Setting
# 13 # [Caller ID Mode] 
 Dial Tone Level Index Setting
# 14 # [Dial Tone Level Index] 
 Busy (or Congestion) Tone Level Index
# 15 # [Busy (or Congestion) Tone Level Index] 
 Tx Audio Level
# 16 # [Tx Audio Level] 
 Auto Dial Time
# 17 # [Auto Dial Time] 
 VM Alert Ring ON/OFF
# 18 # [VM Alert Ring ON/OFF] 
 DTMF only mode ON/OFF
# 19 # [DTMF only mode ON/OFF] 
 Clear Lock Code
# 20 # 
 Fax Module S/W Version
# 21 # [ Version Number ] 
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3.6.2 Table for Test Call
Description
# # 0 [SPC]
+
#2
Test
Call
Mode
Setting Procedure
 Old 8K Markov Test Call
#1
 New 8K Markov Test Call
#2
 New 13K Markov Test Call
#3
 8K Loopback Test Call
#4
 13K Loopback Test Call
#5
 Markov SO54 Test Call
#6
 Loopback SO55 Test Call
#7
 Simple TDSO Test Call
#8
 Full TDSO Test Call
#9
 NV ClearMode
#0
3.7. FCC TEST Menu
# # 0[SPC]
+
#3
FCC
Test
Mode
 Channel Setting
# 1 # [Channel value] *
 AGC Setting
# 2 # [AGC value] *
4. Product Specification
4.1 General Specification
4.1.1 Transmit/Receive Frequency Interval
- CDMA: 45MHz
4.1.2 Number of Channels (Channel Bandwidth)
- CDMA : 20 CH (BW: 1.23MHz)
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4.1.3 Operating Voltage : DC power(Adaptor) : 12V
- Backup Battery : 7.2V Typical
4.1.4 Battery Power Consumption : DC 7.2V (Without FAX)
SLEEP
50mA Typ
CDMA
IDLE
MAX POWER
110 mA Typ
600 mA (24 dBm)
4.1.5 Operating Temperature : -10℃ ~ +50℃
4.1.6 Frequency Stability
- CDMA : ±300Hz
4.1.7 Antenna : Dipole,Omni-directional, 50  ,TNC male
4.1.8 Size and Weight
- Size : 187mm x 140mm x 43 mm (L x W x D )
- Weight :
420g (w/o FAX Module, w/o battery Approximately)
- Weight :
586g (w/o FAX Module, w/ battery Approximately)
- Weight :
479g (w/ FAX Module, w/o battery Approximately)
- Weight :
645g (w/ FAX Module , w/ battery Approximately)
4.1.9 Channel Spacing
- CDMA : 1.25MHz
4.1.10 Battery : Type, Capacity and Operating Time.
Unit = Hours
Mode
7.2V Ni-MH (1800mAh)
Stand-By Time
CDMA
40Hours (Cell power -85dBm, SCI=2)
Talk Time
CDMA
4Hours(About +10dBm)
4.2 Receive Specification
4.2.1 Frequency Range
- CDMA : 869.640 MHz ~ 893.370 MHz
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4.2.2 Local Oscillating Frequency Range
- CDMA : 1739.64MHz ~ 1786.38MHz
4.2.3 Zero Intermediate Frequency
4.2.4 Sensitivity
- CDMA : -104dBm (C/N 12dB or more)
4.2.5 Selectivity
- CDMA : 3dB C/N Degration (With Fch±1.25 kHz : -30dBm)
4.2.6 Spurious Wave Suppression
- Maximum of -80dB
4.2.7 CDMA, Input Signal Range
- Dynamic area of more than -104~ -25 dB : 79dB at the 1.23MHz band.
4.3 Transmit Specification
4.3.1 Frequency Range
- CDMA : 824.640MHz ~ 848.370MHz
4.3.2 Local Oscillating Frequency Range
- CDMA: 1649.64MHz~1696.38MHz
4.3.3 Output Power
- CDMA : 0.25W
4.3.4 Interference Rejection
1) Single Tone :
-30dBm at 900 kHz
2) Two Tone
- 43dBm at 900 kHz & 1700kHz
:
- 32dBm at 900 kHz & 1700kHz
- 21dBm at 900 kHz & 1700kHz
4.3.5 CDMA TX Frequency Deviation
- CDMA : +300Hz or less
4.3.6 CDMA TX Conducted Spurious Emissions
 900kHz : - 42 dBc/30kHz below
 1.98MHz : - 54 dBc/30kHz below
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4.3.7 CDMA Minimum TX Power Control : - 50dBm below
4.4 Frequency Requirements
FWT must cover frequency range,which is described in TIA/EIA/IS-98D standard(Band Class 0).
No of Channels
Boundary Channels
Transmitter Frequency
Receiver Frequency
33
991 ~ 1023
824.040~825.000 MHz
869.040 ~ 870.000 MHz
799
1 ~ 799
825.030~848.970 MHz
870.030 ~ 893.970 MHz
4.5 Charge time
4.5.1 Standard Battery
 10Hr, Normal & Trickle Charge
4.6 Telephony Specification
①
②
③
④
⑤
⑥
Dialing mode : Pulse or DTMF
Feeding Voltage : -48V +/- 10%
Loop Current Limit : About 28 mA
Line impedance : 600 ohm
Hook flash time : 1000ms
Dial Pulse
1) Speed : 10PPS
⑦ DTMF
1) Receivng level : -16dBm ~ 0dBm
2) Signal type : 0,1,2,3,4,5,6,7,8,9,*,#
4.7 Functions of Major Semi-Conductors
Classification
MSM6025-FBGA
Function
Operation control and digital signal processing of the mobile station
Flash MEMORY
(MBM29DL34TF70)
Flash Memory (32Mbit) ; Flash Memory Store of the mobile station
(M29DW323DT)
operation program and mobile i.d. informations & Calibration Data.
(S29JL032H70BAI31)
(K1S161611A)
Its capacity is 16Mbit and in this memory stored are internal flag
information, call-processing data, and timer data from FLASH to
SRAM by MCU.
RFR6122
Converting RF signal into Baseband signal
RFT6122
Converting Baseband signal into RF signal
SRAM MEMORY
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5. Trouble Shooting
5.1 When Rx Carrier is not normal.
BAD
GOOD
BAD
GOOD
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5.2 When Rx parts do not work.
START,POWER IN
BAD
U15 VOLT check
U15 PERIPHERAL
CIRCUIT Check
Check
GOOD
U10(LNA)IN/OUT
Check
BAD
U10 PERIPHERAL
CIRCUIT Check
GOOD
BAD
U10(RFR6122)
IN CHECK
GOOD
Rx PART CHECK
END
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5.3 When Tx parts do not work.
START, Tx CONTROL MODE
U3,U2
VOLTAGE Check
BAD
U3,U2 PERIPHERAL
CIRCUIT Check
BAD
U3 PERIPHERAL
CIRCUIT CHECK
GOOD
U3(RFT6122)
OUTPUT Check
GOOD
FL1 IN/OUT
PART Check
BAD
FL1 PHERIPHERAL
CIRCUIT Check
GOOD
1) CHECK PAM VCC & VREF
VOLTAGES.
2) IF IT DOESN’T WORK,
CHANGE U4
BAD
U4(POWER AMP) IN/OUT
Check
GOOD
ANT1 OUTPUT
Check
BAD
U6,FL2(Coupler,DUPLEXER)
Check
CHECK
GOOD
Tx PART Check
END
28
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.4 When Power is not “Turn On”.
START
VOLTAGE OF
BAD
ADAPTOR IS 12V?
CHANGE
ADAPTOR
GOOD
OUTPUT
VOLTAGE OF D9
BAD
CHANGE
DIODE(D9)
IS 12V?
GOOD
BATT. VOLT IS
BAD
BATT.
GREATER THAN 6.7V?
GOOD
VOLTAGE OF JUNCTION
RECHARGE
BAD
BETWEEN L14 & R116
IS 3.8V?
GOOD
29
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
VOLTAGE OF
BAD
U31 PIN15 IS GREATER
THAN 10V?
GOOD
GOOD
VOLTAGE OF
U19 PIN 5 IS –3.8V?
BAD
CHANGE
CHANGE
U31
Q14 & Q13
CHANGE U19
(Off-Hook State)
(MAX1680)
GOOD
VOLTAGE OF U22
BAD
CHANGE U22
(TC1173)
PIN1 IS 3V?
GOOD
END
30
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.5 When LED do not display.
START
3.8V IS SUPPLIED
BAD
REFER TO
POWER PARTS
AT PIN1,3 OF LD1,2,3?
GOOD
BASE OF Q2 OR Q3
AFTER
BAD
BAD
CHANGE Q2 OR Q3
IS 0.5 ~ 0.7V?
CHANGE
LED
LED DISPLAY?
GOOD
BASE OF Q5 OR Q6
BAD
AFTER CHANGE Q5 OR Q6
IS 0.5 ~ 0.7V?
BAD
CHANGE
FAX
MODULE
BAD
CHANGE
MAIN
BOARD
LED DISPLAY?
GOOD
BASE OF Q8 OR Q9
BAD
AFTER CHANGE Q8 OR Q9
IS 0.5 ~ 0.7V?
LED DISPLAY?
GOOD
END
31
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.6 When Rx Audio is not transmitted.
START
PIN35 OF U30
BAD
REFER TO
IS –48V?
POWER PARTS
GOOD
SETUP TEST MODE 8924C
(SERVICE OPTION1, 1kHz TONE)
AND SETUP CALL
GOOD
1kHZ FREQ. SIGNAL
BAD
Check U5,C171
EXIST AT C171?
GOOD
1 kHz FREQ. SIGNAL
BAD
BAD
PIN 9,10,11 OF U32 IS LOW?
EXIST AT PIN3
CHANGE
MAIN
BOARD
OF U32?
GOOD
CHANGE U32
GOOD
1 kHz FREQ. SIGNAL
EXIST AT PIN7
BAD
BAD
POWER IS SUPPLIED TO U33?
OF U33?
GOOD
GOOD
CHANGE U33
END
32
REFER TO
POWER
PARTS
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.7 When TX Audio is not transmitted.
START
PIN35 OF U30 IS
BAD
-48V?
REFER TO
POWER PARTS
GOOD
CONNECT PIN2 OF MJ3
WITH F/G,SUPPLY 1kHz
FREQ
GOOD
1kHz FREQ. SIGNAL
BAD
CHANGE U33
EXIST AT PIN1 OF
U33?
GOOD
1kHz FREQ. SIGNAL
BAD
CHANGE U33
EXIST AT C216,C217?
GOOD
END
33
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.8 When DTMF Signal is not detected.
START
GOOD
AFTER OFF-HOOK
BAD
BAD
PIN35 OF U30 IS -48V?
DIAL TONE IS HEARD?
REFER TO
POWER
PARTS
GOOD
PUSH THE DIAL
BAD
CHANGE SLT
BUTTON, DTMF TONE IS HEARD?
GOOD
FOLLOW Tx
TRANSMITTED PATH
GOOD
A/D CONVERTED DATA AT
BAD
PIN6 OF U13 IS LOW?
PIN12,13,14,15 OF U13?
GOOD
GOOD
CHANGE U13
CHECK DATA LINE,
BAD
D(0),D(1),D(2),D(3)
GOOD
BAD
END
34
CHANGE
MAIN
BOARD
CHANGE
MAIN
BOARD
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.9 When G3 FAX is not transmitted.
CHECK THE CONNECTION
OF FAX MACHINE IN THE
RJ-11 JACK
BAD
CHECK FAX MODE
1.OFF-HOOK HANDSET
2.PRESS‘#’,‘#’,‘7’,‘#’,‘1’,‘*’
SEQUENTIALLY
3.ON-HOOK HANDSET
4. FAX MODE READY
GOOD
CHECK THE CONNECTION
CABLE FOR INTERFACE STATUS
(FAX MODULE TO MAIN)
BAD
CONNECT CABLE
(USING THE FLAT CABLE)
GOOD
BAD
VOLTAGE REGULATOR OUTPUT
VOLTAGE IS 3.3V(PIN5 OF U10)
CHECK THE VOLTAGE
REGULATOR(U10)
GOOD
BAD
32.256MHz FREQ. SIGNAL EXIST
ON PIN1 OF Y1
CHANGE Y1
GOOD
35
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
BAD
32.768kHz FREQ. SIGNAL
CHANGE Y2
EXIST ON PIN1 OF Y2?
GOOD
BAD
RESET OUTPUT VOLTAGE
IS 3.3V(PIN36 OF U2)?
CHANGE U2
GOOD
BAD
CHIP SELECT SIGNAL
EXIST ON PIN30 OF U4?
CHECK THE ADDRESS/DATA
U3, U4
GOOD
TRANSMISSION SIGNAL EXIST
ON CONTROLLER IC(PIN87 OF U2)
BAD
CHECK THE CONTROLLER (U2)
GOOD
FAX TRANSMISSION SIGNAL
EXIST ON TP2?
BAD
GOOD
CHANGE THE FAX MODULE
END
36
CHECK THE OPAMP IC(U1)
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
5.10 When G3 FAX is not received.
CHECK THE CONNECTION
OF FAX MACHINE IN THE
RJ-11 JACK
BAD
CHECK FAX MODE
1.OFF-HOOK
HANDSET
1.OFF-HOOK
HANDSET
2.PRESS
‘#’,
‘#’,
‘7’,
‘#’, ‘1’, ‘*’
2.PRESS’#’,’#’,’7’,’1’,’*’
SEQUENTIALLY
SEQUENTIALLY
3.ON-HOOK
HANDSET
HANDSET
4.3.ON-HOOK
FAX MODE READY
4. FAX MODE READY
GOOD
BAD
CHECK THE CONNECTION
CABLE FOR INTERFACE STATUS
(FAX MODULE TO MAIN)
CONNECT CABLE
(USING THE FLAT CABLE)
GOOD
VOLTAGE REGULATOR OUTPUT
BAD
VOLTAGE IS 3.3V(PIN5 OF U10)?
CHECK THE VOLTAGE
REGULATOR(U10)
GOOD
BAD
32.256MHz FREQ. SIGNAL EXIST
ON PIN1 OF Y1
CHANGE Y1
GOOD
37
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
BAD
32.768kHz FREQ. SIGNAL
CHANGE Y2
EXIST ON PIN1 OF Y2?
GOOD
BAD
RESET OUTPUT VOLTAGE
IS 3.3V(PIN3 OF U22)?
CHANGE U2
GOOD
BAD
CHIP SELECT SIGNAL
EXIST ON PIN30 OF U4?
CHECK THE ADDRESS/DATA
U3, U4
GOOD
FAX RECEIVE SIGNAL EXIST
ON PIN30 OF CN1?
BAD
CHECK THE CABLE
GOOD
FAX TRANSMISSION SIGNAL
EXIST ON TP2?
GOOD
CHANGE THE FAX MODULE
END
38
BAD
CHECK THE OPAMP (U1)
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
6. Block Diagram
6.1 RF Block Diagram
39
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
6.2 Base Band Block Diagram
40
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
6.3 Fax Module Block Diagram
41
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
7. Exploded View
NO
1
2
3
4
5
6
7
8
42
P /N
LS T-260R
D E S C R IP TIO N
H O U S IN G ,U P P E R
M O D U LE A S S Y
P C B A S S Y,M A IN
H O U S IN G ,LO W E R
B A TTE R Y A S S Y, N I-M H
C O VE R A S S Y,B A TTE R Y
A N TE N N A ,W LL,B A S E S E T
A D A P TO R ,A C -D C
LGE CDMA Fixed Wireless Telephone
LST-260B Service Manual
8. PCB Drawing
- Refer to attachment PCB File
8.1 MAIN PCB(LST-260)
[ COMPONENT SIDE]
[SOLDERING SIDE]
8.2 LST-255 / LST260 FAX Module PCB
[COMPONENT SIDE]
[SOLDERING SIDE]
9. Circuit Diagram
- Refer to attachment Circuit Diagram File
9.1 LST-260 MAIN
9.2 LST-260 RF
9.3 LST-255 / LST-260 FAX Module
10. Replacement Parts List
- Refer to attachment Parts List File
10.1 BOM LST-260
10.2 BOM LST-255 / LST-260 FAX Module
43