LG LG-200 User manual

LG-200
SERVICE MANUAL
SERVICE MANUAL MODEL : LG-200

- 1 -
1. PERFORMANCE ..................................................... 2
1-1. HW Features ........................................................... 2
1-2. Memory Requirment ............................................... 2
1.3. Technical Specification ........................................... 3
1-4. GSM band RF Specifications ................................. 7
1-5. DCS band RF Specifications .................................. 8
1-6. Receiver (GSM) ...................................................... 9
1-7. Receiver (DCS) ...................................................... 9
2. TECHNICAL BRIEF .............................................. 10
2-1. Receiver ............................................................... 10
2-2. Transmitter ........................................................... 14
2-3. The PA Circuit and its Control .............................. 17
2-4. 13 MHz Clock ....................................................... 18
2-5. Main Processor and DSP ..................................... 19
2-6. Power Supplies and Control Signals .................... 21
2-7. User Interface Board ............................................ 28
2-8. Testing Set-up and Checking Signals .................. 32
2-9. Dimensions of Main Components. ........................ 43
3. TROUBLE SHOOTING ....................................... 53
3-1. Power Supply Failure ........................................... 53
3-2. Voice Function Failure .......................................... 55
3-3. Display Function Failure........................................ 55
3-4. Transmission & Receiving Failure ........................ 57
3-5. Other Function Failure........................................... 57
4. TEST POINT DATA ............................................... 60
5. ASSEMBLY INSTRUCTIONS ........................... 68
6. BLOCK DIAGRAM ............................................... 73
7. CIRCUIT DIAGRAM ............................................. 74
8. HOW TO DOWNLOAD S/W .............................. 83
9. HOW TO PROCESS CALIBRATION............... 84
10. EXPLODED VIEW .............................................. 90
11. REPLACEMENT PARTS LIST......................... 91
Table Of Contents

- 2 -
1. PERFORMANCE
1-1. HW Features
1-2. Memory Requirment
Item Feature Comment
Battery Li-Ion Battery, 600mAh
Size : 105.9x44.8x19.7mm
Weight : 89g, 77cc
PCB : M/B:99.5x38.3;K/B:99.5x39.4mm
AVG TCVR current(mA) GSM Imax(390mA),DCS Imax(320mA)
Stand by current(mA) ≤5mA
- Talk time 2.5-hour (GSM Tx Level_7)
- Stand by time 85-hour(Paging Period:2 RSSI:-85dBm)
- Charging time 1.5-hour
RX sensitivity GSM:-107dBm, DCS:-104dBm
TX output power GSM (Level 5:33dBm), DCS (Level0: 30dBm)
GPRS compatibility N/A
SIM card type 3v/5v small
Display 128x64
Status Indicator Soft Icons
Keypad : 0-9, #, *, C, P/book, up/down, on/off
ANT External
System connector : N/A
Ear Phone Jack Yes
PC synchronization N/A
Memory : 1MB
Speech coding EFR/FR
Data & Fax N/A
Vibrator Yes
Melody(for Buzzer Function) 22
Voice Recording N/A
C-Mike N/A
Receiver Yes
Speaker Phone N/A
Portable Handsfree Yes, option
Travel Adapter Yes Switching
Options
Application RAM Size ROM Size
GSM Protocol 120KB 880KB
WAP (AUR Browser) N/A N/A
Zi ezText (2 Languages at N/A N/A
the same time)
ART N/A N/A
Voice Memo (3 Minutes) N/A N/A
Phone Book 1KB 2KB
Voice Tag N/A N/A
Game & Accessory 3K 20K
GPRS N/A N/A

1. PERFORMANCE
- 3 -
Item Description Specification
1 Frequency Band GSM900 band
Tx : 890 + n*0.2 MHz
Rx : 935 + n*0.2 MHz
(n = 1 ~ 124)
GSM1800 band
Tx : 1710 + (n-512)*0.2
Rx : 1805 + (n-512)*0.2
(n = 512 ~ 885)
2 Phase error RMS < 5 degrees
Peak < 20 degrees
3 Frequency error < 0.1ppm : = 90 Hz (for GSM900) or 180 Hz (for GSM1800)
5 Power Level 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
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
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
1-3. Technical Specification

- 4 -
Item Description Specification
6 Spectrum due GSM900
to modulation Offset from Carrier(KHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ <1200 -60
1200 ~ <1800 -60
1800 ~ <3000 -63
3000 ~ <6000 -65
≥6000 -71
GSM1800
Offset from Carrier(KHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ <1200 -60
1200 ~ <1800 -60
1800 ~ <3000 -65
3000 ~ <6000 -65
≥6000 -73
7 Spectrum due to GSM900
switching transient Offset from Carrier(KHz). Max. dBc(KHz).
400 -19
600 -21
1200 -21
1800 -24
GSM1800
Offset from Carrier(KHz). Max. dBc
400 -22
600 -24
1200 -24
1800 -27
8 Spurious emissions Conduction, Emission Status, Appendix 1
Conduction, Emission Status, Appendix 2
9 Bit Error Rate GSM900
BER(Class II) <2.439% @-102dBm
DCS1800
BER(Class II) <2.439% @-100dBm

1. PERFORMANCE
- 5 -
Item Description Specification
10 Rx Level Report accuracy GSM900 GSM1800
≥-88 ≥-86 2 2
≥-101 ≥-99 3 2
< -101 < -99 4 2
11 SLR 8 ± 3 dB
12 Sending Response 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 /
13 RLR 2 ± 3 dB
14 Receiving Response Frequency (Hz) Max.(dB) Min.(dB)
100 -12 /
200 0 /
300 2 -7
500 * -5
1,000 0 -5
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.
15 STMR 13 ± 5 dB
16 Stability Margin > 6 dB
17 Distortion dB to ARL (dB) Level Ratio (dB)
-35 17.5
-30 22.5
-20 30.7
-10 33.3
0 33.7
7 31.7
10 25.5
18 Sidetone Distortion Three stage distortion < 10%
19 <Change> System frequency ≤2.5ppm
(13MHz) tolerance
20 <Change>32.768KHz ≤30ppm
tolerance

- 6 -
Item Description Specification
21 Power consumption Full power: < 390mA (GSM) ; < 320mA (DCS)
Standby : 1. Normal ’≤5mA(Mix. power)
2. Using Test mode on DSP Sleep function ≤6mA
22 Talk time GSM/ Level_7 (Battery Capacity 650mA): 130Min
GSM/ Level_7 (Battery Capacity 600mA): 120Min
23 Standby time Under conditions, at least 85 hours:
1. Brand new and full 600mAh battery
2. Full charge, no receive/send and keep GSM in idle mode.
3. Broadcast set off.
4. Signal strength display set at 3 level above.
5. Backlight of phone set off.
24 Ringer Volume At least 70dB under below conditions:
1. Ringer set as ringer 7.
2. Test distance set as 50 cm
25 Charge Voltage Fast Charge: < 600 mA
Slow Charge: < 100 mA
26 Antenna display GSM DCS
≥-84dBm -80dBm : 4
≥-89dBm -85dBm : 3
≥-94dBm -90dBm : 2
≥-101dBm -97dBm : 1
≥-105dBm -101dBm : 0
Tolerance: ± 2 dB
27 Battery indicator Level Voltage (v)
0V≤3.5V
1 3.5 ≤V ≤3.7
2 3.7 ≤V ≤3.8
3 3.8 ≤V ≤4.0
4 4.0 ≤V
Tolerance: ± 0.1V
28 Low Voltage Warning 3.5V ± 0.1V
29 Forced shut down Voltage 3.3V ± 0.1V
30 Battery Type 1 Li-Ion battery
Standard Voltage = 3.7V
Battery full charge voltage =4.2V
Capacity: 650mAh/600mAh (Li-Ion);
31 Travel Charger Linear Charger
In put: 110V or 240 VAC, 50/60Hz
Out put: 5VDC ± 0.25V, 500mA (No Load)
Switching-mode charger
In put: 96- 246VAC, 50/60Hz
Out put: 5VDC ± 0.25V, 500mA (No Load)

1. PERFORMANCE
- 7 -
1-4. GSM band RF Specifications
Frequency Stability < ± 90Hz
RF Maximum Power Output 33dBm
RF Output Power Levels 15, decrementing in 2dB steps
Power Control Level 5 33dBm ± 2dB
Power Control Level 6 31dBm ± 3dB
Power Control Level 7 29dBm ± 3dB
Power Control Level 8 27dBm ± 3dB
Power Control Level 9 25dBm ± 3dB
Power Control Level 10 23dBm ± 3dB
Power Control Level 11 21dBm ± 3dB
Power Control Level 12 19dBm ± 3dB
Power Control Level 13 17dBm ± 3dB
Power Control Level 14 15dBm ± 3dB
Power Control Level 15 13dBm ± 3dB
Power Control Level 16 11dBm ± 5dB
Power Control Level 17 9dBm ± 5dB
Power Control Level 18 7dBm ± 5dB
Power Control Level 19 5dBm ± 5dB
TX Frequency Output
Low Channel (Ch 1) 890.2 MHz
Mid Channel (Ch 62) 902.4 MHz
High Channel (Ch 124) 914.8 MHz
TX Frequency Calculation (Ftx) 890 + (ARFCN x 0.2) = Ftx MHz
TX UHF VCO Frequency
Low Channel (Ch 1) 1160.2 MHz
Mid Channel (Ch 62) 1172.4 MHz
High Channel (Ch 124) 1184.8 MHz
TX UHF VCO Freq. Calculation (Ftuhf) Ftx + 270 = Ftuhf MHz
IF VCO Frequency 540 MHz
TX IF Frequency 270 MHz
Rx IF Frequency 270MHz
Phase Error
Peak Phase Error < 20 degrees
RMS Phase Error < 5 degrees

- 8 -
1-5. DCS band RF Specifications
Frequency Stability < ± 180Hz
RF Maximum Power Output 30dBm
RF Output Power Levels 16, decrementing in 2dB steps
Power Control Level 0 30dBm ± 2dB
Power Control Level 1 28dBm ± 3dB
Power Control Level 2 26dBm ± 3dB
Power Control Level 3 24dBm ± 3dB
Power Control Level 4 22dBm ± 3dB
Power Control Level 5 20dBm ± 3dB
Power Control Level 6 18dBm ± 3dB
Power Control Level 7 16dBm ± 3dB
Power Control Level 8 14dBm ± 4dB
Power Control Level 9 12dBm ± 4dB
Power Control Level 10 10dBm ± 4dB
Power Control Level 11 8dBm ± 4dB
Power Control Level 12 6dBm ± 4dB
Power Control Level 13 4dBm ± 4dB
Power Control Level 14 2dBm ± 5dB
Power Control Level 15 0dBm ± 5dB
TX Frequency Output
Low Channel (Ch 512) 1710.2 MHz
Mid Channel (Ch 699) 1747.6 MHz
High Channel (Ch 885) 1784.8 MHz
TX Frequency Calculation (Ftx) 1710.2 + (ARFCN x 0.2) = Ftx MHz
TX UHF VCO Frequency
Low Channel (Ch 1) 1530.2 MHz
Mid Channel (Ch 62) 1567.6 MHz
High Channel (Ch 124) 1604.8 MHz
TX UHF VCO Freq. Calculation (Ftuhf)Ftx + 180 = Ftuhf MHz
IF VCO Frequency 540 MHz
TX IF Frequency 180 MHz
Rx IF Frequency 270MHz
Phase Error
Peak Phase Error < 20 degrees
RMS Phase Error < 5 degrees

1. PERFORMANCE
- 9 -
1-6. Receiver (GSM)
1-7. Receiver (DCS)
RX Frequency Input
Low Channel (Ch 1) 935.2 MHz
Mid Channel (Ch 62) 947.4 MHz
High Channel (Ch 124) 959.8 MHz
RX Frequency Calculation (Frx) 935 + (ARFCN x 0.2) = Frx MHz
RX UHF VCO Frequency
Low Channel (Ch 1) 1160-1230 MHz
Mid Channel (Ch 62) 1205.2 MHz
High Channel (Ch 124) 1217.4 MHz
RX UHF VCO Freq. Calculation 1229.8 MHz
(Fruhf)F
rx + 270 = Fruhf MHz
RX VCO Frequency 540 MHz
Demodulation Frequency 270 MHz (540/ 2)
IF Frequency 270 MHz
BER (Bit Error Ratio) Type II BER <2.4% at -102dBm
Type II BER <0.1% at -15dBm
RX Frequency Input
Low Channel (Ch 1) 1805.2 MHz
Mid Channel (Ch 62) 1842.6 MHz
High Channel (Ch 124) 1879.8 MHz
RX Frequency Calculation (Frx) Ftx + 95 Mhz = Frx MHz
1535-1610 MHz
RX UHF VCO Frequency
Low Channel (Ch 1) 1535.2MHz
Mid Channel (Ch 62) 1572.6 MHz
High Channel (Ch 124) 1609.8 MHz
RX UHF VCO Freq. Calculation (Fruhf)Frx - 270 = Fruhf MHz
RX VCO Frequency 540 MHz
Demodulation Frequency 270 MHz (540/ 2)
IF Frequency 270 MHz
BER (Bit Error Ratio) Type II BER <2.4% at -102dBm
Type II BER <0.1% at -15dBm