LG B1300 Service Manual

B1300

SERVICE MANUAL

Table of Contents

Chapter 1 - Performance

1-1. Performance ………………………………………….. 1-2. HW Feature ……………………………………………

Chapter 2 – Technical Brief

2-1. The RF Chipset ……………………………………… 2-2. The PA Circuit ………………………………………. 2-3. Peripheral Circuit …………………………………… 2-4. Digital Baseband Chip ……………………………… 2-5. Analog Baseband Chip ……………………………… 2-6. CPU Memories ………………………………………. 2-7. Power Supplies ………………………………………. 2-8. Battery Charge Interface …………………………. 2-9. System Connector …………………………………. 2-10. Keypad Switches and Scanning ………………….. 2-11. Display Interface ……………………………………. 2-12. Microphone ………………………………………….. 2-13. Receiver/Speaker/Buzzer ………………………… 2-14. Headset Interface ………………………………….. 2-15. Back-light Illumination …………………………… 2-16. Vibrator ………………………………………………

……………………

11 15

16 16

18 20 20

22 24

26 27 28 28 29 29 29

Chapter 3 – Failure List

Chapter 4 – Trouble Shooting

4-1. Power Supply ………………………………………… 4-2. Software Download ………………………………… 4-3. Voice Function ……………………………………… 4-4. Display Function …………………………………….

……………………

32 33 34 35

Table of Contents

Chapter 5 – Test Point Data

5-1. Component Side(1-1) ………………………………. 5-2. Component Side(1-2) ………………………………. 5-3. Keypad Side(2-1) …………………………………….

Chapter 6 – Assembly Instructions

1. Remove Battery Cover …………………………………

2. Remove Battery ………………………………………….

3. Remove Screws …………………………………………

4. Turn Handset Up ………………………………………..

5. Take off Front Panel …………………………………..

6. Take off Keypad & Metal-Dome …………………….

7. Take off Mainboard …………………………………….

8. Take off Battery Connecter & MIC & Vibrator …..

9. Turn Mainboard Down …………………………………

10. Take off Antenna ……………………………………...

11. Take off Shielding Cover …………………………….

……………………

37 41 45

48 48

49 49

49 50 50

51 51

52 52

Chapter 7 – Block Diagram

1. RF Section ………………………………………………..

2. Baseband Section ……………………………………….

Chapter 8 – Circuit Diagram

Chapter 9 – Tooling List

Chapter 10 – Equipment List

Chapter 11 – Exploded View &

……………………

Replacement Part List

Chapter 12 – Repair Record Form

……………………

53 54

Chapter 1. Performance

1-1 Performance

Item Description Specification

EGSM900 band Tx: 890 + n*0.2 MHz Rx: 935 + n*0.2 MHz (n = 0 ～ 124)

Tx: 890 + (n-1024)*0.2 MHz

1 Frequency Band

Rx: 935 +(n-1024)*0.2 MHz (n = 975 ～ 1023)

GSM1800 band Tx: 1710 + (n-512)*0.2 Rx: 1805 + (n-512)*0.2 (n = 512 ～ 885)

2 Phase error

3 Frequency error

4 Power Level

RMS < 5 degrees Peak < 20 degrees

< 0.1ppm ~ =90 Hz (for GSM900)

or 180 Hz (for GSM1800)

GSM900

Control Level Power level Tolerance

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

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

-4 -

Item Description Specification

GSM1800

Control Level Power Level Tolerance

0 30 dBm ±2dB 1 28 dBm ±3dB 2 26 dBm ±3dB 3 24 dBm ±3dB 4 22 dBm ±3dB 5 20 dBm ±3dB

4 Power Level

6 18 dBm ±3dB 7 16 dBm ±3dB 8 14 dBm ±3dB

9 12 dBm ±4dB 10 10 dBm ±4dB 11 8 dBm ±4dB 12 6 dBm ±4dB 13 4 dBm ±4dB 14 2 dBm ±5dB 15 0 dBm ±5dB

GSM900

Offset from Carrier

(KHz).

100 200 250 400

600 ~ <1200

1200 ~ <1800 1800 ~ <3000 3000 ~ <6000

Spectrum due to

modulation

≧6000

GSM1800

Offset from Carrier

(KHz).

100 200 250 400

600 ~ <1200

1200 ~ <1800 1800 ~ <3000 3000 ~ <6000

≧6000

Max.

dBc

+0.5

-30

-33

-60

-63

-65

-71

Max.

dBc

+0.5

-30

-33

-60

-65

-73

-5 -

Item Description Specification

Spectrum due to switching

transient

7 Spurious emissions

8 Bit Error Rate

GSM900

Offset from Carrier

(KHz).

400 600

1200

Max.

dBm

-19

-21

-24

1800

GSM1800

Offset from Carrier

(KHz).

400

600 1200 1800

Conduction, Emission Status, Appendix 1 Conduction, Emission Status, Appendix 2

Max.

dBm

-22

-24

-27

GSM900 BER(Class II) <2.439% @-102dBm DCS1800 BER(Class II) <2.439% @-102dBm

9 Rx Level Report accuracy

10 SLR

11 Sending Response

12 RLR

GSM900 GSM1800

>= -88 >= -86 2 2 >= -101 >= -99 3 2 < -101 < -99 4 2

8 +/- 3 dB

Frequency(Hz) Max.(dB) Min.(dB)

100 -12 200 0

300 0 -12 1,000 0 -6 2,000 4 -6 3,000 4 -6 3,400 4 -9 4,000 0

2 +/- 3 dB

-6 -

Item Description Specification

Frequency(Hz) Max.(dB) Min.(dB)

100 -12

200 0

300 2 -7

500 * -5 1,000 0 -5

13 Receiving Response

3,000 2 -5 3,400 2 -10 4,000 2

* Mean that Adopt a straight line in between 300Hz& 1,000Hz to be Max. level in the range.

14 STMR 13 +/- 5 dB

15 Stability Margin > 6 dB

dB to ARL (dB) Level Ratio (dB)

-35 17.5

-30 22.5

16 Distortion

-20 30.7

-10 33.3 0 33.7 7 31.7

10 25.5

17 Side tone Distortion Three stage distortion < 10%

<Change>System frequency

(13MHz) tolerance

<Change>32.768KHz

tolerance

≦ 2.5ppm

≦ 30ppm

Full power: < 280mA (GSM) ;

20 Power consumption

< 220mA (DCS)

Standby : Normal : <=5mA

21 Talk time

GSM/ Level_7 (Battery Capacity 720mA): 180Min

-7 -

Item Description Specification

Under conditions, at least 150 hours:

1.Brand new and full 720mAh battery

2.Full charge, keep GSM in idle mode

22 Standby time

23 Ringer Volume

3.Broadcast set off.

4.Signal strength=-82dBm, DRX=9multiframes

5.Back light of phone set off, no press keypad

At least 90dB under below conditions:

1. Ringer set as ringer 7.

2. Test distance set as 10 cm

24 Charge Voltage

25 Antenna display

26 Battery indicator

27 Low Voltage Warning

Fast Charge: < 720 Ma Trickle Charge: < 35 mA

Level (RSSI)

0 RSSI<=-104 1 -103<=RSSI<= -98 2 -97 <=RSSI<= -92 3 -91 <=RSSI<= -86 4 -85 <=RSSI<= -76 5 -75 <=RSSI

Level (RSSI)

0 3.300≦V≦3.504 1 3.504≦V≦3.570 2 3.570≦V≦3.686 3 3.686≦V≦3.935 4 3.935≦V

3.504V

28 Forced shut down Voltage 3.35V

1 Li-Ion battery

29 Battery Type

Standard Voltage = 3.7V Battery full charge voltage =4.2V Capacity: 720mAh (Li-Ion);

-8 -

Item Description Specification

Linear Charger In put: 110V or 220 VAC, 50/60Hz

Out put: 5VDC+/-0.25V, 500mA (No Load)

30 Travel Charger

Switching-mode charger In put: 96- 246VAC, 50/60Hz

Out put: 5VDC+/-0.25V, 500mA (No Load)

-9 -

1-2 HW Feature

Item Feature Comment

Battery Li-Ion Battery, 720mAh

AVG TCVR current (mA)

Stand by current (mA) <=5mA

- Talk time

- Stand by time

- Charging time

RX sensitivity GSM:-107dBm, DCS:-105dBm

TX output power

GPRS compatibility N/A

SIM card type 3v/5v small

Display 128x64

Status Indicator Soft Icons

Keypad

ANT Internal

System connector Yes

GSM Imax(280mA),DCS Imax(220mA)

3-hour (GSM Tx Level_7) TBD-hour(Paging Period:5 RSSI:-82dBm) 2-hour

GSM (Level 5:32dBm), DCS (Level0: 29.5dBm)

0-9, #, *, C, Phone Book,up/down, On/Off Hook

Ear Phone Jack N/A

PC synchronization N/A

Memory 2MB

Speech coding EFR/FR/HR

Data & Fax N/A

Vibrator Yes

Melody 15 default + 5 user edit

Voice Recording N/A

C-Mike N/A

Receiver Yes

Speaker Phone Yes

Portable Handsfree Yes, option

Travel Adapter Yes

Options

Switching

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Chapter 2. Technical Brief

Circuit Description

2-1 The RF Chipset

The B1300 RF integrates the TRF6150 transceiver IC, TX/RX VCO, Power amplifier (RF3110), Front End Module 8450T(switchplexer, RF-SAW filter), for dualband transmitting and receiving function.

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2-1-1 The Receiver

The RF receive signal( EGSM 925Mhz – 960MHz, DCS 1805Mhz – 1880Mhz) is input via the antenna or coaxial connector. An antenna matching circuit is between the antenna and the connector.

An t

EGSM ba n d

Di p l e x e r

DCS 18 0 0

ban d

EGSM

Swi t c h

DCS 18 0 0

Swi t c h

An t e n n a Swi t c h Mod u l e

SAW

LPF

SAW

LPF

Fr o n t End Mod ul e

EGSM-Rx

EGSM-Tx

DCS1800-Rx

DCS1800-Tx

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The RF receive signal( EGSM 925Mhz – 960MHz, DCS 1805Mhz – 1880Mhz) is input via the antenna or coaxial connector. An antenna matching circuit is between the antenna and the connector.

Module(FEM8450T) to switch either Rx or Tx path on. When the Rx path is turned on, the RF receive signal then feeds into two paths, EGSM Rx and DCS1800 Rx.

This Front End Module contains two RF SAW filters, DCS SAW Filter to filter any unwanted signal apart from the DCS Rx band. And the GSM SAW filter in the Front End Module is to filter out unwanted signal beyond the GSM Rx band. These two paths are then connected to the GSMLNA and DCSLNA of TRF6150 respectively.

The RF receive signal is amplified by LNAs in TRF6150, and then the signal then feeds into quadrature demodulator for mixing with LO which is produced by the main synthesiser of TRF6150 and external TX/RX VCO. TX/RX VCO will generate 2 times of RX frequency in EGSM band and half times of RX frequency in DCS band to minimize the DC offset generated by self mixing.

In TRF6150, the quadrature demodulator produce baseband(I/Q) signal . This I/Q signal is amplified by two variable gain amplifiers and filtered by low pass filter, and then fed to baseband IC in differential mode.

2-1-2 The TX IF Modulator

The TX I & Q signals from baseband IC are fed to Pin#18-21 of the TRF6150, where they are then modulated onto a TX IF by the modulator inside TRF6150. The TX IF frequency is listed as below.

EGSM Band

From To AUX VCO= 2 x IF Frequency

CH 1 CH 26 858 MHz

CH 27 CH 43 852.8 MHz

CH 44 CH 91 858 MHz

CH 92 CH 108 842.4 MHz

CH 109 CH 985 858 MHz

CH 986 CH 1002 842.4 MHz

CH 1003 CH 1024 858 MHz

- 13 -

DCS Band

From To AUX VCO= 2 x IF Frequency

CH 512 CH 532 832 MHz

CH 533 CH 549 837.2 MHz

CH 550 CH 575 832 MHz

CH 576 CH 597 858 MHz

CH 598 CH 614 837.2 MHz

CH 615 CH 662 858 MHz

CH 663 CH 679 852.8 MHz

CH 680 CH 727 858 MHz

CH 728 CH 744 852.8 MHz

CH 745 CH 792 858 MHz

CH 793 CH 809 847.6 MHz

CH 810 CH 857 858 MHz

CH 858 CH 874 847.6 MHz

CH 875 CH 885 858 MHz

The signal TX LO IF (416 ~ 429Mhz) is produced by the AUX VCO (832 ~ 858MHz), which has been divided down by a factor of 2 .

2-1-3 The Translation Loop Transmitter

The translation loop approach has many advantages over a traditional upconverter solution.

A typical upconverter transmitter usually consists of an IF modulator followed by a mixer for

upconversion to RF. In the translation loop transmitter, the RF transmit signal is instead

generated directly by a voltage controlled oscillator (VCO), the phase of which is locked to

the modulated IF reference in a fast phase-locked-loop. Because a VCO is inherently

a lower-noise source than a mixer, the translation loop transmitter produces a low noise floor,

so no subsequent high-selectivity filtering is necessary, and the diplexer or other post-PA filter

of the conventional approach is eliminated. This saves power and cost, as the insertion loss

of the duplexer is eliminated, and the output level of the power amplifier can be reduced.

- 14 -

The transmit signal is generated directly by a external TX/RX VCO (VON1885C28DKB).

In the feedback path, the RF transmit signal is mixed with the off-chip main VCO to produce

the desired TXIF (416 ~ 429Mhz). This TXIF signal from the feedback path is then compared

to the TXIF signal from the IF modulator at the detector. The resulting signal after passing

a low pass filter drives the external TX/RX VCO.

A high side injection, i.e. RF = LO - IF, is used in the EGSM band upconversion while a low

side injection, i.e. RF = LO + IF, is used in the DCS band upconversion.

This upconversion scheme, with appropriate TXIFs, allows for a single wide-band VCO to

be used.

2-2 The PA Circuit

The RF3110 is a triple-band GSM/DCS/PCS power amplifier module that incorporates an

indirect closed loop method of power control. This simplifies the phone design by eliminating

the need for the complicated control loop design. The indirect closed loop is fully self

contained and required does not require loop optimization. It can be driven directly from the

DAC out-put in the baseband circuit.

The indirect closed loop is essentially a closed loop method of power control that is invisible

to the user. Most power control systems in GSM sense either for-ward power or collector/

drain current. The RF3110 does not use a power detector. A high-speed control loop is

incorporated to regulate the collector voltages of the amplifier while the stages are held at a

constant bias. The V RAMP signal is multiplied and the collector voltages are regulated to

the multiplied V RAMP voltage.

- 15 -

2-3 Peripheral Circuit

Temperature Sensor

When the chip is not transmitting or receiving, its temperature can be measured by sensing

the voltage on the external resistor from pin 31 to ground.

From –40 to +85 C, the resistor voltage varies linearly from 0.9V to 1.35V.

Regulator and Serial Data Interface

TRF6150 built in 3 voltage regulators to supply internal functions and external RF componen

ts. The serial interface of TRF6150 consists of a 3-wire serial bus, comprising DATA,

CLOCK and STROBE signals. These signals are used to enter control words into the chip.

The control words contain information for programming the regulators, the synthesizers and

the receiver.

13 MHz Clock

The 13 MHz-clock consists of a TCXO (TOA1300VPM4DKG-SM2) which oscillates at a

frequency of 13MHz. It acts as time base of all synthesizers and Baseband.

2-4 Digital Baseband Chip : HERCROM20, F741529

HERCROM20 is a chip implementing the digital baseband processing of a GSM mobile

phone. It combines a TMS320C54X (LEAD2) DSP, a micro controller ARM7TDMIE, an

internal 4Mbit RAM memory, and their associated application peripherals.

The HERCROM20 supports the following features:

• CPU & DSP

• Memory Interface (MEMINT)

• Interrupt Controller

• I2C / Micro Wire Interface

• Serial Port Interface (SPI)

• UART Control/Interface

• Display Interface

• SIM Card Interface

• I/O System Connector Interface

• Radio Interface (RIF)

• JTAG Interface

• Real Time Clock (RTC)

• General Timers / Watch Dog Timer

• Keypad Control

• Backlight Control

• Vibrator Control

- 16 -

System Block Diagram of Hercrom20

- 17 -

2-5 Analog Baseband Chip : Nausica_CS, TWL3012B

The TWL3012B device includes a complete set of baseband functions that perform the

interface and processing of the following, voice signals, the baseband in-phase (I) and the

quadrature (Q) signals, which support both the single-slot and multislot modes.

The TWL3012B device also includes associated auxiliary RF control features, supply voltage

regulation, battery charging controls, and switch on/off system analysis.

The TWL3012B device supports the following features.

• Voiceband Coder / Decoder (codec)

• Baseband codec single and multislot with I/Q RF interface

• Automatic Power Control (APC) and Automatic Frequency Control (AFC)

• Voiceband Serial Port (VSP), Baseband Serial Port (BSP), and MCU Serial Port (USP),

Timing Serial Port (TSP).

• SIM Card Interface

• Battery Charging Interface (BCI)

• Six Low-Dropout, Low-Noise, Linear Voltage Regulators (VREG)

• Voltage Reference and Power On Control (VRPC)

• Five-channel analog-to-digital converter (MADC)

- 18 -

System Block Diagram of Nausica_CS

- 19 -

Peripheral

2-6 CPU Memories

Flash ROM

An 32Mbit programmable ROM which is capable of being written to while still in circuit.

Contains all the main command software for the mobile.

SRAM

A 4MBit SRAM memory is embedded in the HERCROM20 which is used for ARM7 & DSP

execution

2-7 Power Supplies

There are six regulators in the Nausica_CS . Those regulators are dedicated power supplies,

which provides most of the power requirements for the Baseband and RF circuits.

Each of these regulators can be controlled by Nausica_CS internal registers.

These are configured as shown in the following Figure and table.

Regulator Voltage Powers

Regulator 1 VR1 1.8V+/-0.15 Digital Core & RTC

Regulator 1B VR1B 2.0V+/-0.2 Nausica_CS Internal logic

Regulator 2 VR2 2.9V+/-0.1 Memory device

Regulator 2B VR2B 2.85V+/-0.15 Peripheral

Regulator 3 VR3 2.85V+/-0.15 Nausica _CS analog supply

SIM Regulator

3V+/-0.3 5V+/-0.5

Table1. – Power Supply

SIM Card

Permanent

On/Off

Permanent

On/Off

- 20 -

Power supply

- 21 -

2-8 Battery Charge Interface

The charging device is a dc voltage source of 7 V absolute maximum. An external PMOS

power transistor in series with a power Schottky diode connected between VCHG and VCC3

of the TWL3012B device controls the current flow from the charging device to the main

battery. The role of the Schottky diode is to prevent reverse leakage current from the main

battery in case the charging device is connected to the mobile phone without delivering

any voltage at its output (charging device not plugged into the ac wall outlet, for example).

The main function of the battery charger interface is the charging control of both

Ni-MH/Ni-Cd/Li-Ion cell battery with the support of the microcontroller. In case of a

rechargeable backup battery, it also delivers a trickle charge current to the backup battery

from the main battery. The charging scheme for the Li-Ion battery is constant current first

(typical current is 1xC) followed by constant voltage charging once a certain voltage

threshold is reached (4.2 V typical). Charging is stopped when the charging current at

constant voltage has decreased down to C/20 (typical).

In addition to the above charging schemes, another scheme is systematically applied when a

battery charger is connected to a switched-off mobile phone: a constant charging current

(typically C/20) is applied to the battery when the battery voltage is lower than 3.6 V.

If the battery voltage is lower than 3.3 V (battery partially discharged or fully discharged) the

mobile phone is not started until the battery gets sufficiently recharged to greater than 3.3 V;

when this happens, the micro-controller is started to control the fast charge cycle of the main

battery, and the C/20 current is switched off.

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