LG Z20LCD1 Schematic
Website:http://biz.LGservice.com
e-mail: http://www.LGEservice.com/techsup.html
LCD TV SERVICE
MANUAL
FACTORY MODEL: 20LV1R. AUSBZA
MODEL: Z20LCD1
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
- 1 -
CONTENTS
CONTENTS ......................................................................................................................................2
PRODUCT SAFETY .......................................................................................................................3
SPECIFICATION ...............................................................................................................................6
SVC REMOCON……………... .....................................................................................................8
TROUBLE SHOOTING ..................................................................................................................9
BLOCK DIAGRAM.........................................................................................................................13
WIRING DIAGRAM .........................................................................................................................15
EXPLODED VIEW ...............…………………………….......................................... ..... .................... 16
REPLACEMENT PARTS LIST ............................…...............……………………………................ 18
SVC. SHEET .................................................................................................................................
- 2 -
SAFETY PRECAUTIONS
- 3 -
SERVICING PRECAUTIONS
- 4 -
.
- 5 -
- 6 -
2.
8.
Resolutions
10.
Storage Environment
SPECIFICATION
NOTE: Specifications and others are subject to change without notice for improvement.
1. Application range
1.1 This spec sheet is applied all of the 20" LCD TV
1.2 Not included spec and each product spec in this spec sheet apply correspondingly to the following each country
standard and requirement of Buyer
2. Specification
Each part is tested as below without special appointment.
2.1 Temperature: 20±5°C
2.2 Relative Humidity: 65±20%
2.3 Power Voltage: input voltage (110V±10%, 50/60±3 Hz)
* Standard Voltage of each product is marked by models
2.4 Specification and performance of each parts are followed each drawing and specification by part number in
accordance with BOM.
2.5 The receiver must be operated for about 30 minutes prior to the adjustment.
3.General Specificat i o n (TV)
No Item Specification
1. Input Signal RF (NTSC-M), Video, S-Video, Component Video, Graphic (VGA)
Component Support 480i, 576i, 480P, 576P, 720P, 1080i
3. Input Voltage
4. Market USA
5. Screen Size 20 inch Wide
6. Vertical refresh rate 56 Hz to 75 Hz
7. Horizontal frequency 31.5 kHz
9. Operating Environm ent
110V±10%, 50/60±3 Hz
640 x 480
Temp: 0 ~ 40 deg, Humidity: 10% ~ 80 %
Temp: -10 ~ 50 deg, Humidity: 5% ~ 85 %
- 7 -
4. External Input Format
4-1. AV/S-Video/Component Video Inputs
Video system NTSC
AV (Composite Video)
S-Video
Component Video
4-2. TV RF Inputs
Amplitude 1.0Vpp (including sync)
Impedance 75 ohm terminated
Video system NTSC
Y signal amplitude 1.0Vpp (including sync)
C signal amplitude 0.286Vpp
Impedance 75 ohm terminated
HDTV 480i, 480p, 720p, 1080i
Y signal amplitude 1.0Vpp (including sync)
Pr,(R-Y) / Pb ,(B-Y) signal amplitude 0.7Vpp
Impedance 75 ohm terminated
TUNER SIGNAL
Receiving System NSTC-M
Channel Coverage NSTC-M
Tuner ChangHong AF5-U2F11RW
AIR CATV
VHF Low band 55.25~127.25 55.25~127.25
VHF High band 133.25~361.25 133.25~361.25
UHF band 367.25~801.25 367.25~801.25
Picture carrier Sound carrier
IF Frequency 45.75 MHz 41.25MHz
Impedance 75 ohm terminated
LEVEL 70dBuV
- 8 -
- 9 -
SVC REMOCON
Key Function
POWER
DISPLAY
MUTE
CH
VOL
0~9/100
PRE-CH
PC
V-CHIP
Press to turn on/off the TV. The TV is never completely powered
off unless it is physically unplugged.
Display current status
Temporarily interrupt the sound or restore
Press ▲ or▼ to brows through the TV channels which are not
erased. To view a blocked channel, use the digit buttons to access
the channel and enter your access code.
Press + or – to adjust the volume.
To select a TV channel directly
To return the last channel you were watching.
To change PC mode (only for Z15LCD1)
Press this button to setup parental control.
TV/VIDE
O
SLEEP
MTS/SAP
Up/Down/
Left/Right
MENU
CAPTION
Select your input source: press repeatedly to select TV, AV1, AV2,
S-Video or Component Video mode, according to where you
connected your external source.
With this key you can set a time period after which the TV should
switch itself to standby. Press the key repeatedly to select the
number of minutes. The counter runs from 0,30,60,90,120
minutes. The timer begins to count down from the number of
minutes selected after the display has disappeared.
Press this key to activate Multi-channel Television Sound, Stereo
or Mono sound.
Up/Down to select the function in the Menu.
Left/Right to enter the function or adjust the value
Press repeatedly to display OSD menu or exit the menu or
sub-menu.
Press this button to bring up closed caption setup menu.
- 10 -
TROUBLE SHOOTING
No Power
Check power
NG
Plug in power cord and interface
OK
Check F901, BD901
NG
Replace F901 or BD901
OK
Check the load
Check IC901
NG
Replace IC901 or Q901
OK
Check T901
NG
Replace T901
OK
Check D904, D905
Replace D904, D905
NG
OK
Replace Q903, ZD902, IC903 IC902
Check Q903, ZD902, IC903 IC902 and
NG
OK
Check Q906, IC905 and relative circuit
1. No Power (No LED indicator)
cord and board
- 11 -
2. No Display (LED indicator green)
Check the source
OK
Reset source
NG
Check LVDS cable
NG
Replace LVDS cable
OK
Check 12V power supply
NG
Return to “1”
OK
OK
Check U406
NG
Replace U406
OK
OK
Check panel
NG
Replace panel
Check main board power
Check I2C communication
Repair I2C communication relative circuit
NG
No display
NG
Repair the keyboard
OK
Check 5V_SB
NG
Check every chip power supply
OK
NG
Check I2C communication
OK
Check keyboard
Replace I2C communication component
Check oscillistor
NG
Replace oscillistor
Can’t start
3. Can’t start (LED indicator yellow)
- 12 -
4. Abnormal Display
Check the source
OK
Reset source
NG
Check signal filter circuit
NG
Replace the filter or inductance
Repair each relative circuit
RF signal
Check TV system setup
OK
Check TU100
Replace TU100
AV, S-video signal
OK
Check LVDS cable
Check input signal
OK
OK
OK
NG
Replace LVDS cable
OK
Check panel
Replace panel
NG
Abnormal display
component PC signal
- 13 -
5. No Sound
Check the source
OK
Reset source
Check signal filter circuit
NG
Replace the filter or inductance
OK
NG
SIF signal
Check TV system setup
OK
Check TU100
Replace TU100
AV, component, S-video, PC signal
NG
Check Amplifier TDA7266D U601
Replace U601
Check Earphone jack
NG
Replace the Earphone jack
OK
Check speaker
NG
Replace speaker
Check relative circuit
NG
No sound
- 14 -
1. Main Board
PHILIPS LOC1 TV Block Diagram
Speaker (2Wx 2)
Key PAD
VIDEO 1
S-VIDEO
IF Tuner
TDA7266D
Headphone
SDA/SCL
IR
PC D-sub
Flash
Audio IF
Audio Output
HD input
RGB
Y/PR/PB
PI5V
PI5V
PC Audio
AV Audio
HD Audio
Switch
Video H/V Output
PC H/V Input
SDA/SCL
TTL output
TTL TO LVDS
LVDS output
PANEL
AU or CPT
Power Internal
DC 12V
DC 5V
Inverter
Switch
DDC
SDA/SCL
EEPROMM24C32
VSCL/VSDA
SawFilter /VF45A3M
SawFilter /AF45A3M
BLOCK DIAGRAM
330W
330W
4052
Philips
1336MK
Philips
SST39V F020B
AC 100～220 Input
Inverter For TV
LOC1
TDA15501E
THC63LVDM84R
32K
EEPROM
4052
Audio AMP
- 15 -
2. Power Board
- 16 -
WIRING DIAGRAM
- 17 -
Loading...