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LCD TV
SERVICE MANUAL
CHASSIS : ML-012B

MODEL : RU-20LA61
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.




ST
MONO SAP DPM
STEREO
SAFETY PRECAUTIONS

IMPORTANT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in
the Schematic Diagram and Replacement Parts List.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to
prevent X-RADIATION, Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.



General Guidance Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source,
An lsolation Transformer should always be used during connect an electrical jumper across the two AC plug prongs.
the servicing of a receiver whose chassis is not isolated from Place the AC switch in the on positioin, connect one lead of
the AC power line. Use a transformer of adequate power rating ohm-meter to the AC plug prongs tied together and touch other
as this protects the technician from accidents resulting in ohm-meter lead in turn to each exposed metallic parts such as
personal injury from electrical shocks. antenna terminals, phone jacks, etc.
If the exposed metallic part has a return path to the chassis, the
It will also protect the receiver and it's components from being measured resistance should be between 1M and 5.2M.
damaged by accidental shorts of the circuitary that may be When the exposed metal has no return path to the chassis the
inadvertently introduced during the service operation. reading must be infinite.
An other abnormality exists that must be corrected before the
If any fuse (or Fusible Resistor) in this TV receiver is blown, receiver is returned to the customer.
replace it with the specified.
Leakage Current Hot Check (See below Figure)
When replacing a high wattage resistor (Oxide Metal Film Plug the AC cord directly into the AC outlet.
Resistor, over 1W), keep the resistor 10mm away from PCB. Do not use a line Isolation Transformer during this check.
Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
Keep wires away from high voltage or high temperature parts. between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Due to high vacuum and large surface area of picture tube, Measure the AC voltage across the resistor using AC
extreme care should be used in handling the Picture Tube. voltmeter with 1000 ohms/volt or more sensitivity.
Do not lift the Picture tube by it's Neck. Reverse plug the AC cord into the AC outlet and repeat AC
voltage measurements for each esposed metallic part. Any
Before returning the receiver to the customer, voltage measured must not exceed 0.75 volt RMS which is
corresponds to 0.5mA.
always perform an AC leakage current check on the exposed In case any measurement is out of the limits sepcified, there is
metallic parts of the cabinet, such as antennas, terminals, etc., possibility of shock hazard and the set must be checked and
to be sure the set is safe to operate without damage of repaired before it is returned to the customer.
electrical shock.
Leakage Current Hot Check circuit

AC Volt-meter




Good Earth Ground
such as WATER PIPE,
To Instrument's CONDUIT etc.
0.15uF
exposed
METALLIC PARTS


1.5 Kohm/10W




- 2 -
TABLE OF CONTENTS

SPECIFICATIONS.................................................................4


DESCRIPTION OF CONTROLS ...........................................5


ADJUSTMENT INSTRUCTIONS ..........................................9


PRINTED CIRCUIT BOARD ...............................................10


BLOCK DIAGRAM...............................................................13


EXPLODED VIEW...............................................................14


EXPLODED VIEW PARTS LIST .........................................15


REPLACEMENT PARTS LIST ............................................16


SCHEMATIC DIAGRAM..........................................................




- 3 -
SPECIFICATIONS

Model RU-15LA61 RU-20LA61



Horizontal size (Inches) 18.3 22.8
Height (Inches) 14.8 18.3
Thickness (Inches) 6.7 8
Weight (pounds) 13.9 21.6


Power requirements DC 12V/4.5A DC 15V/4.5A


Television system NTSC


Television channels VHF : 2 ~ 13, UHF : 14 ~ 69
Cable : 01 ~ 125


Television Screen LCD Panel


External antenna impedance 75


Power consumption 50 W 70 W


Audio output 3W+3W 5W+5W


Adapter (DC power) In : AC 100-240V ~ 1.5A-0.6A
In: AC 100-240V ~ 1.5A-0.6A In: AC 100-240V ~ 1.6A-0.7A
50/60Hz 50/60Hz, 115~180VA
50/60Hz
Out : DC 12V, 5A
Out: DC 12V, 5A Out: DC 15V, 4.5A

For use only with Model No. For use only with Model No.
* CAUTION : For use only with Model No. SAD6012SE AC Adapter, manufactured by H &
E co., Ltd.
SAD6012SE AC Adapter, man- SAD7015SE AC Adapter,
ufactured by H & E co., Ltd. manufactured by H & E co., Ltd.


Power supply cordset : Standard North America three wire earth-grounding with
flexible cord SJT type or higher type.

* CAUTION : If replacement becomes necessary, replace with an exact duplicate.
Contact any LG authorized service center.




- 4 -
DESCRIPTION OF CONTROLS


Front of the TV




ST
MONO SAP DPM
STEREO




ST
MONO SAP DPM
STEREO




Stereo Indicator
SAP Indicator
Mono Indicator DPM Indicator
(RU-15LA61 Only)


Power/Standby indicator
Illuminates red in standby mode, Illuminates
green when the TV is turned on.


Remote Control Sensor




- 5 -
DESCRIPTION OF CONTROLS

Back of the TV




* Kensington
Security System
Connector




RU-15LA61 PC Input PC sound Input DC 12V Input




ANT IN Y PB PR L R PC INPUT PC VIDEO (MONO) L AUDIO R DC 12V
+75 SOUND
COMPONENT(480i/480p/720p/1080i) AUDIO VIDEO IN
DVD/DTV IN




Antenna Input DVD/DTV IN Audio/Video Input
(Component (480i/480p/720p/1080i),
RU-20LA61 AUDIO) Input DC 15V Input




DC IN (15V)
ANT IN Y PB PR L R VIDEO (MONO) L AUDIO R
+75
COMPONENT(480i/480p/720p/1080i) AUDIO VIDEO IN
DVD/DTV IN




- This manual mainly explains the features for the RU-15LA61




- 6 -
DESCRIPTION OF CONTROLS

Side of the TV




Side Control Panel



ch Channel Buttons


ST
MONO SAP DPM
STEREO




vol Volume Buttons



enter Enter Button
Side Connection Panel
menu Menu Button

tv
TV