LG KG920 User manual

Date: April, 2006 / Issue 1.0
Service Manual Model : KG920
Service Manual
KG920
kg920 cover 2006.5.15 10:6 AM ˘`1

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1. INTRODUCTION...................................5
1.1 Purpose ..................................................... 5
1.2 Regulatory Information ............................... 5
1.3 Abbreviations .............................................. 7
2. PERFORMANCE ..................................9
2.1 H/W Features...............................................9
2.2 Technical Specification ..............................18
3. TECHNICAL BRIEF............................23
3.1 Transceiver (SI4210) .................................23
3.2 PAM (SKY77328) ..................................... 27
3.3 26 26 MHz Clock (VCTCXO) .....................28
3.4 Power Supplies for RF Circuits (RF LDO) .28
3.5 Digital Main Processor (AD6527B) ............30
3.6 Analog Main & Power Management
Processor (AD6535) ..................................36
3.7 Battery Charging Block ..............................43
3.8 MUMTI-MEDIA INTERFACE .....................47
3.9 MIDI IC(YMU787) ......................................59
3.10 MEMORY
(512Mbits NOR + 128Mbits PSRAM) ......63
3.11 Keypad Switches and Scanning ..............66
3.12 Main Microphone .....................................68
3.13 Main Receiver..........................................69
3.14 Headset Interface ....................................70
3.15 BLUETOOTH(LBMA-2C67B2) ................71
3.16 Mini-SD ....................................................72
3.17 FLIP SWITCH ..........................................73
3.18 VIBRATOR ..............................................74
3.19 Audio CODEC..........................................74
3.20 KEY backlight ..........................................75
4. TROUBLE SHOOTING.......................76
4.1 RF Component ..........................................76
4.2 BT Trouble .................................................86
4.3 Power On Trouble......................................89
4.4 Charging Trouble .......................................91
4.5 Vibrator Trouble .........................................93
4.6 SIM Card Trouble ......................................95
4.7 KEY backlight Trouble ...............................97
4.8 Side KEY backlight Trouble (SUB board) ..99
4.9 RTC Trouble ............................................101
4.10 Swivel Trouble .......................................103
4.11 LCD Trouble ..........................................105
4.12 Camera Trouble.....................................108
4.13 Speaker Trouble ....................................120
4.14 Headphone Trouble ...............................122
4.15 Receiver Trouble ...................................124
4.16 Microphone Trouble...............................126
5. DOWNLOAD AND CALIBRATION...128
5.1 Download.................................................128
5.2 Calibration................................................134
6. BLOCK DIAGRAM ...........................140
7. Circuit Diagram................................141
8. pcb layout ........................................149
9. ENGINEERING MODE .....................157
9.1 About Engineering Mode .........................157
9.2 Access Codes..........................................157
9.3 Key Operation..........................................157
9.4 Engineering Mode Menu Tree .................157
9.5 BB Test [MENU 1] ...................................158
9.6 RF Test [MENU 2] ...................................160
9.7 MF mode [MENU 3] .................................160
9.8 Trace option [MENU 4] ............................161
9.9 Call timer [MENU 5] .................................161
9.10 Fact. Reset [MENU 6]............................162
9.11 S/W version [MENU 7]...........................162
9.12 MM S/W Download [MENU 8] ...............162
12. EXPLODED VIEW & REPLACEMENT
PART LIST ..................................... 163
12.1 Exploded View ...................................... 163
12.2 Replacement Parts ................................165
12.3 Accessory ............................................. 194
Table Of Contents

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1. INTRODUCTION
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1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of this model.
1.2 Regulatory Information
A. Security
Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company”s employees, agents, subcontractors, or person working on your
company”s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system. There are may be risks of toll fraud
associated with your telecommunications system. System users are responsible for programming and
configuring the equipment to prevent unauthorized use. The manufacturer does not warrant that this
product is immune from the above case but will prevent unauthorized use of common-carrier
telecommunication service of facilities accessed through or connected to it.
The manufacturer will not be responsible for any charges that result from such unauthorized use.
B. Incidence of Harm
If a telephone company determines that the equipment provided to customer is faulty and possibly
causing harm or interruption in service to the telephone network, it should disconnect telephone
service until repair can be done. A telephone company may temporarily disconnect service as long as
repair is not done.
C. Changes in Service
A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the this phone or compatibility with the
network, the telephone company is required to give advanced written notice to the user, allowing the
user to take appropriate steps to maintain telephone service.
D. Maintenance Limitations
Maintenance limitations on this model must be performed only by the manufacturer or its authorized
agent. The user may not make any changes and/or repairs expect as specifically noted in this manual.
Therefore, note that unauthorized alternations or repair may affect the regulatory status of the any
remaining warranty.
1. INTRODUCTION

1. INTRODUCTION
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E. Notice of Radiated Emissions
This model complies with rules regarding radiation and radio frequency emission as defined by local
regulatory agencies. In accordance with these agencies, you may be required to provide information
such as the following to the end user.
F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.
G. Interference and Attenuation
Phone may interfere with sensitive laboratory equipment, medical equipment, etc.Interference from
unsuppressed engines or electric motors may cause problems.
H. Electrostatic Sensitive Devices
ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated by the sign.
Following information is ESD handling:
• Service personnel should ground themselves by using a wrist strap when exchange system boards.
• When repairs are made to a system board, they should spread the floor with anti-static mat which is
also grounded.
• Use a suitable, grounded soldering iron.
• Keep sensitive parts in these protective packages until these are used.
• When returning system boards or parts like EEPROM to the factory, use the protective package as
described.

1. INTRODUCTION
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1.3 Abbreviations
For the purposes of this manual, following abbreviations apply:
APC Automatic Power Control
BB Baseband
BER Bit Error Ratio
CC-CV Constant Current - Constant Voltage
DAC Digital to Analog Converter
DCS Digital Communication System
dBm dB relative to 1 milli watt
DSP Digital Signal Processing
EEPROM Electrical Erasable Programmable Read-Only Memory
ESD Electrostatic Discharge
FPCB Flexible Printed Circuit Board
GMSK Gaussian Minimum Shift Keying
GPIB General Purpose Interface Bus
GSM Global System for Mobile Communications
IPUI International Portable User Identity
IF Intermediate Frequency
LCD Liquid Crystal Display
LDO Low Drop Output
LED Light Emitting Diode
OPLL Offset Phase Locked Loop

1. INTRODUCTION
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PAM Power Amplifier Module
PCB Printed Circuit Board
PGA Programmable Gain Amplifier
PLL Phase Locked Loop
PSTN Public Switched Telephone Network
RF Radio Frequency
RLR Receiving Loudness Rating
RMS Root Mean Square
RTC Real Time Clock
SAW Surface Acoustic Wave
SIM Subscriber Identity Module
SLR Sending Loudness Rating
SRAM Static Random Access Memory
PSRAM Pseudo SRAM
STMR Side Tone Masking Rating
TA Travel Adapter
TDD Time Division Duplex
TDMA Time Division Multiple Access
UART Universal Asynchronous Receiver/Transmitter
VCO Voltage Controlled Oscillator
VCTCXO Voltage Control Temperature Compensated Crystal Oscillator
WAP Wireless Application Protocol

2. PERFORMANCE
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2.1 H/W Features
1) System Specification
Item Target Specification
Form Factor Twisted Bar
Size 108 x 50 x 18mm
Weight 150g
Battery 3.7V, 820 mAh LI-Ion
Talk Time Up to 3h : GSM Tx Level 7
Standby Time Up to 180 hrs : Paging Period 9, RSSI 85dBm
Antenna Internal Antenna
LCD Main: 262K Colour QVGA(240x320) TFT
Camera Built-in CCD 5M Pixels Camera
Back Light(Key Pad) LED
Back Light colour(Key) Blue(with orange colour filter)
Vibrator Yes
Buzzer Yes
C-MIC Yes
Receiver Yes
Earphone Jack Yes / Jack
SIM Socket Yes (SIM Block Type) →3V only
Volume Key Yes
Voice Key N/A
I/O Connect 24 Pin
Basic Accessory Travel Adaptor / Battery / Ear Phone + Mic/Data Cable/Mini-SD Card
Option N/A
2. PERFORMANCE

2) Feature
2. PERFORMANCE
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Function Target Specification
RSSI (5 Level)
Battery Charging (5 Level)
Display RTC
Multi-Language (English, French, German, Spanish, Dutch, etc.)
Quick Access Mode(HOT KEY)
PLMN/Service Indicator
Number of Keys : 30 Key (including Soft key, side key, Hot key)
Keypad Soft Function Keys : 3
International Access (+)(long 0)
HotKey : Zoom+/-, MP3, Schedule
Normal Features Last Dialled Number : 20
Last Received Number : 10
Last Missed Number : 10
Scratch Pad Memory(Save a phone number in call) : 1
Call Waiting
Call Swap
Call Retrieve
Any Key Answer
Automatic Redial
Calling Line Identification
Call Management Full Call divert
Speed Dialling
Last Number Redial
Multi-party Call (Conference Call)
Voice Recording Voice Recording (20 Sec/20 message)
Automatic Network Selection
Network Manual Network Selection
Network Service Status

2. PERFORMANCE
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Read Cell Broadcast
Cell Broadcast Cell Broadcast Categories
Cell Broadcast Message Language
Number Store and Recall
Alpha Store and Recall
Search the Phone Book in call
Scroll by alpha
Last Number Dialled (20)
Phone Book
Last Number Missed (10)
Last Number Received (10)
Copy & Move
Fixed Dial Number
Service Dial Number
Email Entry
Entry : 1000 names
Last Call Timer
Last Call Charge Units
Call Cost Total Call Timer
Total Charge Units
Visible, Audible Call Time/Cost Indication
Key tone setting
Key / Ring Tone Volume (5 Level)
Ring Tone Pattern 20(fixed) + My Folder Ring tone 24(Default)
Audio Ring Type:
Silent / Vibrator & Ring / Ring only / Vibrator only/Ring after Vibrator
Earpiece Volume (5 Level)
Mute
DTMF DTMF Signalling
DTMF Enable & Disable

2. PERFORMANCE
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Call Forwarding All Incoming Calls
Call Forwarding On Busy
Call Forwarding No Reply
Call forwarding Not-reachable
Supplementary Services
Call Barring All Outgoing Calls
Call Barring All Outgoing International Calls
Call Barring All incoming Calls
Call Barring All incoming Calls when roaming
Conference Call (up to 5 calls)
Plug-In Type : 3V Only
SIM
Service Provider Lock & Network Lock
SIM Toolkit (Class 1, 2, 3)
Prepaid SIM Operation
Read Message
Write and Edit Message
Send and Receive Message
Reply to Message
Forward Message
Extract Number from Message
Message Status
Short Message Message Unread Indicator
Settable Message Center Number,
Visible and Audible Message
Voice Mail
Settable Voice Mail Center Number
Message Protocol
Message Overflow Indicator
Message Center Number
Multi-Band Support of Multi-band & Mode
Development & Test Facility
Miscellaneous Function Field Test Facility
Display Software Version
IMEI

2. PERFORMANCE
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Text Input T9 (Predictive word input)
Organizer Calendar & Memo
World Time Setting Local time
Number of Selectable Cities: 76
Unit converter Currency/Surface/Length/Weight/Temperature/Volume/Velocity/Shoes
/Clothes
Calculator Addition, Subtraction, Multiplication, Division, trigonometrical function ,
logarithmic function
Scheduler , Memo Sync
Phone Book Sync
PC Sync Internet Kit supporting PC OS (2000,ME,XP)
Contents D/Load (Wallpaper/Ringtone)
Data Circuit (up to 9.6kbps)
GPRS GPRS Multi slot Class 10
Game Java Download Games
Menu Quick Access Mode
Read Software Version
Handset Battery Charging Mode
Restore Factory Setting
Security
SIM Lock
Emergency Call
12/24 hour
Calendar with Automatic Leap Year Adjustment
Time Zone Adjustment
Real Time Clock Alarm Manager
On Alarm Event
Display Message on Alarm Event
Others Profiles

2. PERFORMANCE
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Read and Save MMS Message
Preview MMS Message
Send and Receive MMS Message
Previous, Next slide
MMS (3GPP R5) Set timer
Remove media
Delete slide
Attach MMS media (Text, Audio, Picture)
Audio: SP-MIDI, I-Melody (AMR: supported), MIDI, SMAF, WAV
Picture: GIF87,GIF89a, PNG, JPEG, WBMP
WAP version 2.0 @ TELECA
JAVA MIDP 2.0 @ Esmertec
E-mail (CIS/Europe) SMTP, POP3
Bluetooth Generic Access Profile,
Service Discovery application Profiles(profile v1.1),
Generic Objective Exchange Profile,
Serial Port Profile, Headset Profile (profile v1.1),
Audio Gateway,
Dial-Up Networking profile (profile v1.1),
File Transfer Profile (Server, Client) (profile v1.1),
Object Push Profile (Server, Client) (profile v1.1, Vcard2.1 only),
Hands-Free profile (profile v1.0),
Basic Printing Profile (profile v1.0)

2. PERFORMANCE
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3) RF Transmitter
NO Item EGSM DCS1800
100kHz ~ 1GHz -36dBm -36dBm
1GHz ~ 12.75GHz -30dBm
1GHz ~ 1710MHz -30dBm
1710MHz ~ 1785MHz -36dBm
1785MHz ~ 12.75GHz -30dBm
100kHz ~ 880MHz -57dBm -57dBm
880MHz ~ 915MHz -59dBm -59dBm
915MHz ~ 1GHz -57dBm -57dBm
1GHz ~ 1.710GHz -47dBm -47dBm
1.710GHz ~ 1.785GHz -53dBm -53dBm
1.785G ~ 12.75GHz -47dBm -47dBm
1GHz ~ 1.850GHz
1.850GHz ~ 1.910GHz
1.910GHz ~ 12.75GHz
30M ~ 1GHz -36dBm -36dBm
1G ~ 4GHz -30dBm
1G ~ 1710MHz -30dBm
1710M ~ 1785MHz -36dBm
1785M ~ 4GHz -30dBm
30M ~ 880MHz -57dBm
880M ~ 915MHz -59dBm
915M ~ 1GHz -57dBm
1G ~ 1710MHz -47dBm
1710M ~ 1785MHz -53dBm
1785M ~ 4GHz -47dBm
1G ~ 1850MHz
1850M ~ 1910MHz
1910M ~ 4GHz
Conducted
Spurious
Emission
MS allocated
Channel
Idle Mode
MS allocated
Channel
Idle Mode
Radiated
Spurious
Emission
Frequency Error
Phase Error
< 0.1ppm
Peak < 20 degrees RMS < 5 degrees
1
2
3

2. PERFORMANCE
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NO Item EGSM DCS1800
Frequency Error Under 3dB below reference sensitivity 3dB below reference sensitivity
Multipath and Interference RA250: ±300Hz RA130: ±400Hz
Condition HT100: ±180Hz HT100: ±350Hz
TU50: ±160Hz TU50: ±260Hz
TU3: ±230Hz TU1.5: ±320Hz
0 ~ 100kHz +0.5dB 0 ~ 100kHz +0.5dB
200kHz -30dB 200kHz -30dB
250kHz -33dB 250kHz -33dB
400kHz -60dB 400kHz -60dB
600 ~ 1800kHz -60dB 600 ~ 1800kHz -60dB
1800 ~ 3000kHz -63dB 1800 ~ 6000kHz -65dB
3000 ~ 6000kHz -65dB ≥ 6000kHz -73dB
≥6000kHz -71dB
400kHz -19dB 400kHz -22dB
600kHz -21dB 600kHz -24dB
1200kHz -21dB 1200kHz -24dB
1800kHz -24dB 1800kHz -27dB
Frequency offset 800kHz
Intermodulation product should
be Les s than 55dB below the
level of Wanted signal
Power control Power Tolerance Power control Power Tolerance
Level (dBm) (dB) Level (dBm) (dB)
533
+3030 +3
631
+3128 +3
729
+3226 +3
827
+3324 +3
925
+3422 +3
10 23 +3520
+3
11 21 +3618
+3
12 19 +3716
+3
13 17 +3814
+3
14 15 +3912
+4
15 13 +31010
+4
16 11 +5118
+4
17 9 +5126
+4
18 7 +5134
+4
19 5 +5142
+5
15 0 +5
Output RF
Spectrum
Due to
modulation
Due to Switching
transient
Intermodulation attenuation
Transmitter Output Power
4
5
6
7

2. PERFORMANCE
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2) Receiver
NO Item GSM900 DCS1800
Sensitivity (TCH/FS Class II) -105dBm -105dBm
Co-Channel Rejection
(TCH/FS Class II, RBER, TUhigh/FH) C/Ic= 7dB C/Ic= 7dB
Adjacent Channel Rejection 200kHz C/Ia1= -12dB C/Ia1= -12dB
400kHz C/Ia2= -44dB C/Ia2= -44dB
Wanted Signal: -98dBm Wanted Signal: -96dBm
Intermodulation Rejection 1’st interferer: -44dBm 1’st interferer: -44dBm
2’nd interferer: -45dBm 2’nd interferer: -44dBm
Blocking Response Wanted Signal: -101dBm Wanted Signal: -101dBm
(TCH/FS Class II, RBER) Unwanted Signal: Depend Unwanted Signal: Depend
on freq. on freq.
1
2
3
4
5

2. PERFORMANCE
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2.2 Technical Specification
Item Description Specification
EGSM
TX: 890 + (n-1024) x 0.2 MHz
RX: 935 + (n-1024) x 0.2 MHz (n=975~1024)
DCS
1Frequency Band TX: 1710 + (n-512) x 0.2 MHz
RX: 1805 + (n-512) x 0.2 MHz (n=512~885)
PCS
TX: 1810 + (n-512) x 0.2 MHz
RX: 1905 + (n-512) x 0.2 MHz (n=512~885)
2Phase Error RMS < 5 degrees
Peak < 20 degrees
3Frequency Error < 0.1 ppm
EGSM
Level Power Toler. Level Power Toler.
533 dBm 2dB 13 17 dBm 3dB
631 dBm 3dB 14 15 dBm 3dB
729 dBm 3dB 15 13 dBm 3dB
827 dBm 3dB 16 11 dBm 5dB
925 dBm 3dB 17 9 dBm 5dB
10 23 dBm 3dB 18 7 dBm 5dB
11 21 dBm 3dB 19 5 dBm 5dB
4Power Level 12 19 dBm 3dB
DCS, PCS
Level Power Toler. Level Power Toler.
030 dBm 2dB 8 14 dBm 3dB
128 dBm 3dB 9 12 dBm 4dB
226 dBm 3dB 10 10 dBm 4dB
324 dBm 3dB 11 8 dBm 4dB
422 dBm 3dB 12 6 dBm 4dB
520 dBm 3dB 13 4 dBm 4dB
618 dBm 3dB 14 2 dBm 5dB
716 dBm 3dB 15 0 dBm 5dB

2. PERFORMANCE
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Item Description Specification
EGSM
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600~ <1,200 -60
1,200~ <1,800 -60
1,800~ <3,000 -63
3,000~ <6,000 -65
5Output RF Spectrum 6,000 -71
(due to modulation) DCS, PCS
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600~ <1,200 -60
1,200~ <1,800 -60
1,800~ <3,000 -65
3,000~ <6,000 -65
6,000 -73
EGSM
Offset from Carrier (kHz) Max. (dBm)
Output RF Spectrum 400 -19
6(due to switching transient) 600 -21
1,200 -21
1,800 -24

2. PERFORMANCE
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Item Description Specification
DCS, PCS
Offset from Carrier (kHz). Max. (dBm)
Output RF Spectrum 400 -22
6(due to switching transient) 600 -24
1,200 -24
1,800 -27
7Spurious Emissions Conduction, Emission Status
EGSM
8Bit Error Ratio BER (Class II) < 2.439% @-102 dBm
DCS, PCS
BER (Class II) < 2.439% @-100 dBm
9RX Level Report Accuracy 3 dB
10 SLR 8 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 0 -12
11 Sending Response 1,000 0 -6
2,000 4 -6
3,000 4 -6
3,400 4 -9
4,000 0 -
12 RLR 2 3 dB
Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 2 -7
500 *-5
13 Receiving Response 1,000 0 -5
3,000 2 -5
3,400 2 -10
4,000 2
*Mean that Adopt a straight line in between 300 Hz and
1,000 Hz to be Max. level in the range.

2. PERFORMANCE
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Item Description Specification
14 STMR 13 5 dB
15 Stability Margin > 6 dB
dB to ARL (dB) Level Ratio (dB)
-35 17.5
-30 22.5
-20 30.7
16 Distortion -10 33.3
033.7
731.7
10 25.5
17 Side Tone Distortion Three stage distortion < 10%
18 System frequency 2.5ppm
(26 MHz) tolerance
19 32.768KHz tolerance 30ppm
At least 58 dBspl under below conditions:
20 Ringer Volume 1. Ringer set as ringer.
2. Test distance set as 1 m
21 Charge Current Fast Charge : Typ. 700 mA
Slow Charge : Typ. 70 mA
Antenna Bar Number Power
5-85 2 dBm
5 → 4-85 2 dBm
22 Antenna Display 4 → 3-90 2 dBm
3 → 2-95 2 dBm
2 → 1-100 2 dBm
1 → 0-105 2 dBm
Battery Bar Number Voltage
03.36 ~ 3.54 V
23 Battery Indicator 1 3.55 ~ 3.66 V
23.67 ~ 3.72 V
33.73 ~ 3.84 V
43.85 V ~
24 Low Voltage Warning 3.55 0.03V (Call)
3.48 0.03V (Standby)