LG B1300 Service Manual
B1300
SERVICE MANUAL
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 ………………………………………………
……………………
……………………
4
4
10
11
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 …………………………………….
……………………
……………………
30
32
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
37
41
45
48
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 &
……………………
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……………………
……………………
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Replacement Part List
Chapter 12 – Repair Record Form
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53
53
54
55
61
64
65
73
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
5
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
-60
-60
-63
-65
-71
Max.
dBc
+0.5
-30
-33
-60
-60
-60
-65
-65
-73
-5 -
Item Description Specification
6
Spectrum due to switching
transient
7 Spurious emissions
8 Bit Error Rate
GSM900
Offset from Carrier
(KHz).
400
600
1200
Max.
dBm
-19
-21
-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
-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%
18
19
<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
- 10 -
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.
- 11 -
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
- 12 -
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
Permanent
On/Off
Permanent
Permanent
On/Off
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.
- 22 -
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