SAMSUNG SGH600DYXEU Service Manual

SERVICE

GSM Mobile Cellular Phone

SGH-600

GHI

JKL

MNO

PQRS

TUV

WXYZ

ABC

/OK

DEF

Manual

GSM Mobile Cellular Phone CONTENTS

1. General Description

2. Circuit Description

3. Specification

4. Manual Adjustment Test Procedure

5. Troubleshooting

6. PCB Views

7. Electrical Parts List

8. Exploded Views and Parts List

9. Block Diagram

10. Schematic Diagrams

Samsung Electronics Co.,Ltd.

ELECTRONICS

1. General Description

1-1 GSM System

1-1-1 Calls

GSM¨is an acronym for Global System for Mobile communications©, using TDMA for wide-area cellular operation. The GSM system consists of the sub-systems shown; The Mobile Station (MS) talks to the Base Station System (BSS) via an RF air interface. The Base Station System (BSS) consists of Base Transceiver Station (BTS) and a Base Station Controller (BSC). The microwave link between BTS and BSC is called an Abis interface. Generally one BSC controls 20 to 30 BTSs, and a Mobile Switching Center (MSC) controlling the traffic among different cells would be reported back from a number of BSSs. A Visitor Location Register (VLR) will be allocated to one MSC to find the mobiles out of their home cell by listing them to VLR. The MSC would also be connected to the Home Location Register (HLR), the Authentication Center (AC) and the Equipment Identity Register (EIR) So the system verify that the users and equipment are legal subscriber.

1-1-2 Channels

Channels used in the GSM system can be divided into two classes - Logical and Physical channel. Physical channels can be described in terms of their frequency and time domain characteristics. They are the actual frequencies and timeslots the MS and BS transmits or receives on. The logical channels are mapped onto these physical channels logically. Any particular and instant, physical channels may be control or traffic channels, which determines the function of a physical channel at a particular point in time.

1-1-3 Airinterface of ARFCN (Absolute Radio Frequency Channel Number)

Samsung Electronics 1-1

1 2 3 ... ... ... ... ... 123 124

890.2 MHz 914.8 MHz

935.2 MHz

P-GSM: TX: Fl(n) = 890 + 0.2*n (1≤n≤124)

RX: Fu(n) = Fl(n) + 45

< Fig. 1 ARFCN Diagram >

959.8 MHz

1 2 3 ... ... ... ... ... 123 124

1-2 Samsung Electronics

General Description

1-1-5 Logical Channel

TCH (Traffic CH) is used mainly for transferring the speech information, and the BCH (Broadcast CH) is related to control information.The major function of BCH is transferring information on the downlink for MS synchronization, identification, paging, and controll. BCH is always radiated from every cells and the MS tries to find the BCH which has highest level soon after turned on. The organization of BCH is shown belows; FCCH (Frequency Correction Channel), SCH (Synchronization Channel), and BCCH (Broadcast Control Channel). CCCH (Common Control Channel) will play a role like a message board, and is divided into two control channels - PCH (Paging Channel) and AGCH (Access Grant Channel). SACCH (Slow Associated Control Channel) exists every 12 frames, controlling and controls the TX power level and timing advance of MS, transferring cell information to MS on downlink, transferring the information about RX level, Quality, and RX level of adjacent cell on uplink. FACCH (Fast Associated Control Channel) steals and changes the TCH when needing a Handover. SDCCH (Stand-alone Dedicated Control Channel) and RACH (Random Access Channel) operate during the call setup procedure.

1-1-4 GSM TDMA Timeslots, Frames, and Multiframes

0 1 2 3 4 ... ... ... ... ... ... 24 25

TCH

Multiframe

0 1 2 3 4 ... ... ... ... ... ... 49 50

01234567

BCH

Multiframe

TDMA Frame

T Information F Midamble F Information T Guard

Timeslot

< Fig. 2 Concept of Frames and Timeslots >

1-3Samsung Electronics

General Description

1-2 GSM HHP Feature

1-2-1 Main Set (HHP)

The main set is a microprocessor (KERNEL5)-controlled, full duplex radiotelephone system that provides the user with GSM cellular service through cell sites linked to control centers. It also provides functions related to frequency control, power control, and many user-convenience feactures.

1-2-2 Desktop Charger

The DTC is designed to charge batteries from commercial mains. The charger has two battery receptacles. The forward one is for rapid charging, and the rear for normal charging.

1-2-3 Travel Adaptor

The travel adaptor is designed to operate the main set by supplying power to directly, while charging batteries from commercial mains.

1-2-4 Cigar Lighter Adaptor

A cigar lighter adaptor is used to operate the main set and charger the battery from a 12 volt vehicular electrical system.

1-2-5 Hands Free Car Kit

The Hands Free kit provides unlimited talk time, as power is supplied by the vehicular electrical system, and improved receiving and transmitting due to the external antenna. The Hands Free car kit adapts an external speaker, a hands-free microphone, a bracket, and a cradle for mounting the main set. ¨Hands Free©means user can have a conversation without holding the phone by hand.

1-4 Samsung Electronics

General Description

MEMO

3. Specification

3-1 General Specification

3-1-1 Frequency Range

- Transmit (Uplink): 890 ~ 915 MHz

- Receive (Downlink): 935 ~ 960 MHz

3-1-2 Channel Spacing : 200 kHz

3-1-3 Number of Channels: 124

3-1-4 Frequency Spacing: 45 MHz

3-1-5 Modulation Data Rate

- 270.833 kbits/sec

3-1-6 Frame Period: 4.615 msec

3-1-7 Timeslot Period: 576.9 µsec

3-1-8 Modulation Type: 0.3 GMSK

3-1-9 MS Max Power: 2 W (33 dBm)

3-1-10 MS Min Power: 0.3 W (5 dBm)

3-1-11 Voice Coder Bit Rate: 13 kbits/sec

3-1-12 Input / Output Impedance : 50½

3-1-13 VCO Frequency

- TX VCO : 890 ~ 915 MHz,

- UHF VCO : 1160 ~ 1185 MHz

- VHF VCO : 540 MHz

3-1-14 IF

- 1st RX IF: 225 MHz

- 2nd RX IF: 45 MHz

- 1st TX IF: 270 MHz

3-1-15 VCTCXO Frequency

- 13 MHz (±5 PPM)

3-1-16 Operating Temperature

- Main : Nominal: +15 ¼C ~ +35 ¼C Extreme: -10 ¼C (spec) ~ +55 ¼C

- TA : Nominal: +15 ¼C ~+35 ¼C Extreme: -20 ¼C ~ +55 ¼C

3-1-17 Operating Voltage

- High Voltage: 4.1 V

- Nominal Voltage: 3.7 V

- Low Voltage: 3.4 V

Samsung Electronics 3-1

3-2 Transmitter Specification

3-2-1 Power

3-2-2 Power Ramping Time Level

The power-time template requirements for mobile stations also apply to base stations. The only difference is that, in the base station case, no short burst (random access) exists. To measure the template, the base station has to be operated in its

bursting mode. This test cannot be performed on the base channel, since a base station has to transmit continuously in all time slots. In most cases, an additional channel besides the base channel has to be activated or the transmitter under test is not considered to be configured as a base channel transmitter. The average peak power from the previous part of the test is used as a reference. The time reference is provided by the training sequence in the middle of the burst. The template has to meet the requirements of Fig. 6. Again, the noise level of 70 dBc is dependent on the actual transmitted power level. If this level is below -36 dBm, the absolute level applies. The template is usually evaluated along with the peak power level.

3-2-3 IF Filter

- 270 MHz LC Filter

3-2-4 TX SAW Filter

- Spurious signal atenuating : ²-70 dBc

- Wide Bandwidth to make plane Group delay characteristic

3-2-5 Power Amplifier

- Total Efficiency: 40~45 % at Pin=1mW,

VDD=3.6 V, Pout=3.2 W

Power Peak Norminal Extreme

Control LevelPower (dBm) (dB) (dB)

5 33 ±2 dB ±2.5 dB 6 31 ±3 dB ±4 dB 7 29 ±3 dB ±4 dB 8 27 ±3 dB ±4 dB

9 25 ±3 dB ±4 dB 10 23 ±3 dB ±4 dB 11 21 ±3 dB ±4 dB 12 19 ±3 dB ±4 dB 13 17 ±3 dB ±4 dB 14 15 ±3 dB ±4 dB 15 13 ±3 dB ±4 dB 16 11 ±5 dB ±6 dB 17 9 ±5 dB ±6 dB 18 7 ±5 dB ±6 dB 19 5 ±5 dB ±6 dB

3-2 Samsung Electronics

Specification

dBc

+4 +1

-1

-6

-30

-70 10 8 10 TO

(147 bits)

10 8 10

[µs]

< Fig. 6 Power-Time Template >

Samsung Electronics 3-3

Specification

3-3 Synthesizer Specification

3-3-1 General Specification

- Frequency Hopping : 1 Channel to < 3orms in < 500 mS

- Phase Noise: < 3o RMS

3-3-2 IF Synthesiser

- Synthesizer Frequency: 540 MHz

- Output Signal Drive Level: -10 dB

- 2nd IF LO Output Frequency FIR: 45 MHz

3-3-3 FIR Output

- 1st IF: 225 MHz

- 2nd IF: 45 MHz

- FIR Frequency: 45 MHz

- FIR Level: -17 dBm

3-3-4 Phase Noise Specification

3-4 Receiver Specification

3-4-1 Front-end Specification

- Input Frequency range: 935 MHz ~ 960 MHz

- Gain: 18 dB

- If Frequency range: 540 MHz

- Input Impedance: 150 ½

- Output Load: 1 k½

- Overall Sensitivity: -106 dBm for 9 dB S/N

in 180 kHz

3-4-2 Sensitivity

- Reference Sensitivity Level: -102 dBm

- Channel Width : 180 kHz

- Input Thermal Noise: -121.4 dBm/Hz

- Ouput S/N: > 9 dB

- Noise Figure: < 7 dB

3-4-3 Intermodulation

- Input Useful Signal: -99 dBm

- Interferer: -49 dBm at ± 800 kHz and 1600 kHz

3-4-4 Selectivity

Offset (kHz) Phase Noise (dBc/Hz)

± 200 < -75 ± 250 < -78 ± 400 < -105

> 600 < -105 > 1200 < -105 > 1800 < -113 > 3000 < -115 > 6000 < -121

> 10.0 MHz < -124 > 20.0 MHz < -129 > 30.0 MHz < -134

Signal Type Level

Useful Signal GMSK - 82 dBm

Cochannel GMSK - 9 dBc

± 200 kHz GMSK + 9 dBc ± 400 kHz GMSK + 41 dBc ± 600 kHz GMSK + 49 dBc

3-4 Samsung Electronics

Specification

MEMO

2. Circuit Description

2-1 RF Part

2-1-1 Frequency Generator

The 13MHz reference clock (VCTCXO) drives the logic and RF part. The 13 MHz reference is controlled by the logic (10bits DAC minimum) and is kept to a frequency error less than ±0.1 ppm after synchronization with the GSM network. A 540 MHz oscillator is divided by 2 to generate a fixed 270 MHz VHF LO used in the TX I,Q modulator and mixed by 270 MHz. The UHF LO for the first RX down conversion and the TX offset mixing works in superheterodyne mode to reduce the relative bandwidth and to be able to work at a frequency greater than 1 GHz.

2-1-2 Transmitter

The baseband GSM chipset (Kernel5) generates I and Q baseband signals for the transmit vector modulator. The modulator provides more than 40dBc of carrier and unwanted side-band rejection and produces GMSK modulated signal, the ÔreferenceÕ signal at 270 MHz which passes to the offset phase-locked loop block (OPLL). The OPLL consists of a down-converter, phase detector, loop filter and transmit VCO operating at the final RF output frequency. The down converter mixes the UHF LO (eg. 1172 MHz) with the transmit VCO signal to generate a ÔfeedbackÕ signal at 270 MHz. The ÔfeedbackÕ signal passes via a limiter to one port of the phase detector. The GMSK ÔreferenceÕ signal from the vector modulator passes via a second limiter to the other input port of the phase detector. The phase detector generates an error current proportional to the phase difference between the ÔfeedbackÕ signal from the down-converter and the ÔreferenceÕ signal from the vector modulator. This error current is filtered by a second order low-pass filter to generate an output voltage which depends on the GMSK modulation and the desired channel frequency. This voltage controls the transmit VCO such that the VCO output signal, centered on the correct RF channel, is frequency modulated with the original GMSK data. The centre frequency of the transmit VCO is offset from the UHF LO frequency by 270 MHz. The OPLL acts as a tracking narrowband band pass filter tuned to the desired channel frequency. This reduces the wideband noise floor of the modulation and up-conversion process and provides significant filtering of spurious products. The OPLL architecture results in a low-noise GMSK modulated signal at 902 MHz with very low spurious content. The RF GMSK output from the transmit VCO is fed via TX SAW filter to the RF power amplifier. The peak output power and the profile of the transmitted burst are controlled by means of a closed feedback loop. The RF output from the PA is sampled with a directional coupler. The sampled signal passes to an RF detector diode whose output voltage is dependent on the incident RF level. This ÔfeedbackÕ voltage passes to the inverting input of the loop integrator. A ÔreferenceÕ signal is generated within the baseband section under control of the layer 1 software. The loop maintains zero difference between the ÔfeedbackÕ signal and the ÔreferenceÕ signal. In this way, the amplitude and shape of the transmitted RF burst may be controlled by the baseband processor. In particular, the rise and fall profiles can be controlled to meet the stringent power/time templates and switching transient requirements of GSM 05.05. The RF output passes to the antenna connector via an integrated TX/RX switch and lowpass filter to attenuate the harmonics generated by the power amplifier.

Samsung Electronics 2-1

2-2 Samsung Electronics

2-2 Baseband Part

2-2-1 General Block Diagram

Circuit Description

cmd

power

clk

I,Q Rx

Vmid

I,Q Tx

RS232

3V/ 5V

add

data

add

data

audio

Earphone (Spk/Mic)

Spk/Mic

Vther.

Vcel.

dai

synth.cmd

radio.cmd

keyboard

Vib

voice data

eepdata

KERNEL

B.B. FILTER

SERIAL

EEPROM

VIBRATOR

SIM

TRANSLATOR

MEMORY

(Flash1 + SRAM)

Flash2

(Voice recognisation)

VOCODER

SIM I/F

SIM

2-1-3 Receiver

The incoming RF signal passes through the integrated lowpass filter and TX/RX switch. This is followed by a 947 MHz SAW Band Pass Filter and a bipolar low-noise amplifier (LNA). The HD155101BF includes an active bias circuit which stabilizes the DC operating point of the LNA. The RF signal passes via a second RF SAW filter to the first receive mixer. This mixer is implemented as a Gilbert cell within the HD155101BF. The incoming signal at 947 MHz mixes with the UHF LO at 1172 MHz to generate a 225 MHz IF signal. The IF signal passes from the mixer output via a 225 MHz IF SAW filter to the first IF amplifier. A further internal Gilbert cell mixes the 225 MHz IF signal down to the 45 MHz second IF. The 45 MHz output from the second mixer is filtered and passes to the AGC amplifier. The gain of the AGC amplifier is set by a DC control voltage supplied by the baseband. The usable control range is in excess of 80dB. Finally, the AGC output signal at 45 MHz passes to the demodulator and is mixed down to DC to generate I and Q baseband signals. The baseband signals pass via baseband filter to the baseband A/D converters. The remainder of the channel filtering is performed by the baseband chipset.

(Voice recognition)

< Fig. 3 Baseband Block Diagram >

Samsung Electronics 2-3

2-2-2 ROM1 & SRAM

8M (X16) Flash ROM and 2M (X8) bit SRAM are used. Two devices are merged in one package. This device is a combination memory organized as 524, 288 x 16 bit flash memory and 262, 144 x 8 bit static RAM in one package.

2-2-3 ROM2

A 8M (X16) bit Flash Memory is used for the voice recognition and voice memory. This device is an 8, 388, 608 bit flash memory with batch chip erasing, sector erasing, and byte and word writing using a single 3V power supply.

2-2-4 EEPROM

The kernel requires some external non-volatile memory to store various system parameters, such as RF control calibrations, extra dial stores etc. A 64 K (65, 536) bit device is used. This device is internally organized 8192 x 8. This device features a serial interface and software protocol allowing, operation on a simple, two wire bus.

2-3 SIM

2-3-1 SIM Interface

An interface is provided to a serial port controlling the SIM interface. It can support 5V and 3V SIM interface. The hardware interface consists of SIMVCC, SIMdata I/O, SIMclk output, SIMRST output, and SIMPRES input. The interface is controlled through TX Data, RX Data, control, and status registers. Transmit and receive data may use a 256 byte buffer or be exchanged through single byte registers. SIMVCC may be used to control the power supply to the SIM card.

Circuit Description

2-4 Samsung Electronics

2-4 POWER MANAGEMENT

2-4-1 DC/DC Converter

Our 1 cell Li-ion battery solution requires a up-converting DC/DC conversion circuit for efficiency improvement. The device is a PWM Step-up DC/DC converter IC. Specification is as below;

¥ Vin: 2.75 V ~ 4.2 V ¥ Vout: 3.3 V ~ 4.1 V ¥ Ripple: less than 50 mVpp ¥ Efficiency: typ. 85 % (up to 96%)

2-4-2 Charger Circuitry

The simplified built-in charger circuit diagram is as below ;

Circuit Description

< Fig. 4 Built-in Charger Circuitry >

V DECTECTOR

T DECTECTOR

DC IN DECTECTOR

BAT_VOLT

Buzzer

3.6V

3.3V

3.6V

3.0V

Temperature

DC In

Charger On

SCL

SDA

Vibrator

Backlight LED

CHARGER

B.B

DC/DCBATT

R.F

PAM

RTC

LDO

Samsung Electronics 2-5

2-5 RADIO INTERFACE

2-5-1 RF Block Diagram

2-5-2 Baseband Filter

To control the spectral splatter and thus the intersymbol interference (ISI), filtering is applied to the baseband pulses. The required filtering achieved very simply using a small, low cost discrete LC structure, which has the great advantage of not consuming current.

Circuit Description

LNA

RX SAW

IF SAW

225 MHz

45 MHz LC FILTER

÷6

HARMONIC FILTER

TX/RX SWITCH

ANTENNA SOCKET

947 MHz

270 MHz

Active Bias

HD 155101BF BRIGHT

270 MHz

902 MHz

540 MHz

45MHz

270 MHz

÷2

OPLL LOOP FILTER

TX SAW

POWER AMPLIFIER

RAMP DAC

DETECTOR

POWER CONTROL LOOP

AGC DAC

I Q

AGC AMPLIFIER

IQ DEMOD

IQ MOD

SHIFT ÷2

PHASE DET.

TX VCO

VHF VCO

UHF VCO

13 MHz

AFC DAC

1172 MHz

DUAL SYNTH

RF Buffer

< Fig. 5 RF Block Diagram >

2-6 Samsung Electronics

2-6 AUDIO

2-6-1 Audio Inputs

The Handset provides two audio inputs: ¥ Built in microphone ¥ Connection for external microphone

A microphone biasing amplifier reduces component count in the overall system design: ¥ Supply: 2.2 V regulated to ±20 % ¥ Different output to eliminate possible coupling noise problems, MICBIASP and MICBIASN ¥ Maximum current: 500 uA ¥ Maximum load: 200 pF

2-7 EXTERNAL INTERFACE

A 18 pin connector is mounted on the bottom corner of the PCB. The antenna external connection is on the right hand side of this connector.

2-8 KERNEL SPECIFICATION

2-8-1 FEATURES

¥ Complete Layer 1 support ¥ TDMA burst building (ETSI Rec.5-02) ¥ Coding and interleaving (Rec. 5-03) ¥ GMSK with differential coding (Rec. 5-04) ¥ Programmable power template for Tx burst control ¥ AGC in Receive mode ¥ I,Q inputs or single intermediate frequency (IF) input ¥ Detection of FCCH, SCH, Normal and Dummy Bursts ¥ Flash ROM programming abilities ¥ Auxiliary ADC for battery voltage and temperature monitoring

Circuit Description

Samsung Electronics 2-7

2-8-2 Equalizer

MAJOR FEATURES

¥ Frequency Correction Burst Correction ¥ Frequency Correction Burst Frequency Measurement ¥ Synchronization Burst Long Preamble Correlation ¥ Normal Burst Short Preamble Correlation ¥ Channel Impulse Response Generation ¥ Possible Received Value Generation ¥ Data Equalization ¥ Carrier Power Measurement ¥ Doppler Shift Measurement and Correction ¥ Scaled 7-Bit Soft Decision ¥ I and Q component recovered from Received Data

2-9 VOCODER SPECIFICATION

2-9-1 FEATURE

¥ Complete GSM voice encoding and decoding functions ¥ DTX function ¥ Voice Activity Detection (VAD) output ¥ Fully asynchronous coding and decoding ¥ A-law PCM conversion ¥ DTMF generation ¥ Sidetone level control ¥ Programmable microphone amplifier with two differential input ports ¥ Two programmable audio output amplifiers ¥ 13 MHz master clock

Circuit Description

2-8 Samsung Electronics

2-10 Desk Top Charger

2-10-1 Charging

The desk-top charger contains switching regulator to charge a lithium battery from an DC/DC adaptor. The battery type is detected at pin 15 (MPU) through U5 ( front port) and U26 (rear port). Battery charging current is turned into Vi. Vi is measured at pin 12 (MPU) after R32 and C23 to cancel the noise. When the battery voltage is too low, the charging circuit turns to trickle mode using Q9 and Q11.

2-10-2 Control Part

This circuit contains 4-bit micro controller (U21), including an I/O port, timer, A/D converter to control battery charging. This circuit uses a 4 MHz main clock and +5V power.

BATTERY VOLTAGE DETECTION

Battery voltage from the front port is detected at R20, R18 and measured at pin 13 (MPU). Battery voltage from the rear port is detected at R14, R13 and measured at pin 14 (MPU).

BATTERY TEMPERATURE DETECTION

The charger always detects the battery temperature via NTC thermistor to prevent battery thermal problems. This circuit is composed of parallel resistors because NTC thermistor has log-scale thermal characteristics. If the battery temperature exceeds 55 degrees C, charging stops.

AUTONOMOUS TIMER

If MPU has stopped charging and the timer goes to the ÔonÕ state by an external shock, overcharging may occur. A timer (U7-4) prevents the battery from being overcharged by any unexpected external influence.

Circuit Description

Samsung Electronics 2-9

2-11 Cigar Lighter Adaptor (CLA)

2-11-1 General Description

The CLA is a regulated switched-mode power supply designed for use with a portable HHP. The power supply is connected directly to the phone and provides a voltage path for charging a battery installed in the hand-held portable phone.

2-11-2 Circuit Description

The input voltage range of CLA is from 12 Vdc to 30 Vdc, and the nominal voltage is 13.7 Vdc. The output current is 600 mA. The ripple and noise amplitude is less than 50 mV at the input (12 V ~ 30 Vdc). And the limit settings are shown below;

- Current limit : 600 mA ± 50 mA at nominal input 13.7 V

- Output voltage : 9.0 V (+/- 0.8 V) Vdc at no load.

In addition, the temperature limit is -20 upto +85 ¼C for storage, and 0 to +40 ¼C for operating. The CLA size of SGH-600 is 89.3 x 43 x 27 mm, and the weight is 110 g.

2-12 Travel Adaptor (TA)

2-12-1 General Description

This adaptor is designed for use with a portable hand held phone (HHP). It is a switching-mode power supply connected directly to the phone with a cable, and it provides a voltage for charging a battery installed in the hand held portable phone.

2-12-2 Circuit Description

The input voltage range is 85 ~ 264 Vac, and input frequency is 47 ~ 63 Hz. At an input voltage of 230 Vac (standard input voltage), AC input current is 0.1 A(rms). The output voltage range is 9.0 V ± 10% and the unit maintains current 600 mA ± 30 mA. The operating temperature is 0 ~ 55 ¼C, and for storage

-20 ~ 85¼C. Power ON/OFF cycle is 1.0sec min. The overall size is 74.1 x 28.4 x 79.8 mm and the weight is 65 g without the output DC cable. The charger is an AC/DC switch mode flyback converter featuring constant current and voltage limit. Output cable is two-way DC cable. Maximum output power is 6.4 W.

Circuit Description

2-10 Samsung Electronics

2-13 Hands Free Car kit

2-13-1 General Description

Many states and countries are considering legislation requiring mobile phone users to operate in Hands-Free mode while driving.

Feature of the hands free kit are:

- Power adaptor (600 mA) from vehicle battery to GSM battery pack.

- Ignition sensor for automatic power ON/OFF.

- Car stereo mute function in Hands-Free mode, with programmable output level.

- External microphone input.

- Loudspeaker output.

- Hands-Free operation.

2-13-2 Circuit Description

The input voltage range is from 12V dc to 28V dc, (battery) and input current is 10mA(stanby). The operating temperature is -10 ~ 60 oC, and for storage temperature is - 30 ~ 85 oC(± 5 oC). The charging voltage is DC9V and charging current is MAX 600mA.

2-13-3 Audio Features

- Microphone Sensitivity: -60 dB ± 3 dB

- Speaker S/N: -45 dB ± 3 dB (1W Output)

- Speaker Distortion: 20% below (3W Output)

- Speaker Feature: Impedance 4½, Max 5W Output

- Echo Cancellation: 50 dB (Min)

- Noise Suppression: 15 dB (Min)

Circuit Description

5. Troubleshooting

5-1 Main Set

5-1-1 RX Sensitivity Problem

Samsung Electronics 5-1

RX ON (RF Input - Frequency : CH Freq. + 20 kHz

- RF Amplitude : - 50 dBm)

U204 Input ≥ -60 dBm?

Yes

F200 Input ≥ -60 dBm?

Q200 pin 1 ≥ -65 dBm?

Q200 pin 3 ≥ -50 dBm?

F101 Input ≥ -50 dBm?

U102

Input (pin47, 48)

≥ -55 dBm?

U102 pin 42, 43

≥ -50 dBm?

F100

pin 4, 5 ≥ -50 dBm

(225 MHz)?

U102

pin 38, 39 ≥ -55 dBm

(225 MHz)?

U102 pin 36, 37

≥ -45 dBm (45MHz)?

U102

pin 25, 26, 27, 28 30

mVp_p(20KHz)?

U411 pin 7, 14

1Vp_p(20KHz)?

Check U204, J401, C223

Solder Status k Resolder

Check U109, U204, C224, F200

Solder Status k Resolder

Check C219, L205, C217, C218, C216,

R219 Solder Status k Resolder

Q200, C216 Resolder or Replace

Check L207, L206, R221, C220, C170,

F101 Solder Status k Resolder

Resolder C172, L104, C171

Check U102 (pin 42, 43, 44, 47, 48),

R107, R109, C925, U839, C926, R504

Resolder or Change

Check C168, C167, C164, R137,

F100, C169, L108, L106, R138

Solder status k Resolder

Check C160, C159, C161, C162,

L105, L204 k Resolder or Charge

Check U102, C164, L161 Solder status k Resolder

Resolder or Check U102, C124,

L101, C119, R112 k Resolder

U411, C464, C445, L403, R466, L404,

R465, R462, R468, R443, R445, R444,

L401, L402, R447 k Resolder

5-2 Samsung Electronics

Troubleshooting

5-1-2 TX Power Problem

CH.60 (902 MHz) &

Tx Carrier ON (Power level 5)

F201 Input ≥ - 10 dBm?

RF VCO

≥ -10dBm(1172MHz)?

IF VCO ≥ -10dBm(540MHz)?

TX VCO ≥ -10dBm

(902MHz)?

U202 pin 4

≥ 2.0Vp_p(AC)?

U202, U204, U205, C225 Resolder

or change poor component(s)

R139, C174, U204, U109

Resolder or Change U204, U109

C223, U204 J410 pin 21 Resolder

F201 Resolder or Change F201

ResolderC208, U202 or

replace if damaged.

Resolder R215, C213, R212, C214,

R213, C210, U206, U205,

U202,U203 or replace if damaged.

Resolder FB100, U202, U204

or replace if damaged.

Resolder C147, C146, R135, R133, R134, R132, R131, C142, C138, C139, R504, C165, C927, R121, R120, R123,

C130 or replace if damaged.

Check R208,R209,R210, C943,

F201 or replace if damaged.

F201 Output ≥ -15 dBm?

U202 Input ≥ - 15 dBm?

U202 Output ≥ 30 dBm?

U204 Input ≥ 30 dBm?

U204 Output ≥ 30 dBm?

I/F Connector pin 21

≥ 30 dBm?

Yes

Yes Yes

Yes

U202 pin 5

voltage ≥ 3V rms?

Resolder U202 or

replace if damaged.

Yes

Samsung Electronics

5-3

5-1-3 Base Band

POWER ON

Troubleshooting

‘POWER ON’ does not work

Give Battery Power

Check the Battery Voltage

is less than 3.2V

Charge the Battery

Check the path from BATT to U402

Check the path from D401 to U402

(DC/DC convert circuit)

Check the clock generation circuit

(related to U201 and U200)

U402 pin 5 3.6V

(when pushing pwr Key)

U402 pin 2, 3, 4

3.3V (when pusging pwr Key)

Check for the clock siganl

at U408 pin 83

Check J301

Check the initial operation

END

Yes

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