LG RM-20LA70 User manual

LCD TV
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS : ML-041B
MODEL : RM/RZ-20LA70(RM-20LA70 Rev A)
website:http://biz.LGservice.com
e-mail:http://www.LGEservice.com/techsup.html
*( ) ID LABEL Model No.
*Same looking with new chassis
*Issue Date; 2004. 06

CONTENTS
CONTENTS .............................................................................................. 2
PRODUCT SAFETY ..................................................................................3
SPECIFICATION........................................................................................6
ADJUSTMENT INSTRUCTION ...............................................................10
TROUBLE SHOOTING............................................................................12
BLOCK DIAGRAM...................................................................................17
WIRING DIAGRAM..................................................................................19
EXPLODED VIEW .................................................................................. 20
EXPLODED VIEW PARTS LIST..............................................................21
REPLACEMENT PARTS LIST ............................................................... 22
SVC. SHEET ...............................................................................................

SAFETY PRECAUTIONS
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
An isolation Transformer should always be used during the
servicing of a receiver whose chassis is not isolated from the AC
power line. Use a transformer of adequate power rating as this
protects the technician from accidents resulting in personal injury
from electrical shocks.
It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitry that may be
inadvertently introduced during the service operation.
If any fuse (or Fusible Resistor) in this TV receiver is blown,
replace it with the specified.
When replacing a high wattage resistor (Oxide Metal Film Resistor,
over 1W), keep the resistor 10mm away from PCB.
Keep wires away from high voltage or high temperature parts.
X-RAY Radiation
Warning:
To determine the presence of high voltage, use an accurate high
impedance HV meter.
Adjust brightness, color, contrast controls to minimum.
Measure the high voltage.
The meter reading should indicate
23.5 1.5KV: 14-19 inch, 26 1.5KV: 19-21 inch,
29.0 1.5KV: 25-29 inch, 30.0 1.5KV: 32 inch
If the meter indication is out of tolerance, immediate service and
correction is required to prevent the possibility of premature
component failure.
Before returning the receiver to the customer,
always perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas, terminals, etc., to
be sure the set is safe to operate without damage of electrical
shock.
Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source, connect an
electrical jumper across the two AC plug prongs. Place the AC
switch in the on position, connect one lead of ohm-meter to the AC
plug prongs tied together and touch other ohm-meter lead in turn to
each exposed metallic parts such as antenna terminals, phone
jacks, etc.
If the exposed metallic part has a return path to the chassis, the
measured resistance should be between 1MΩand 5.2MΩ.
When the exposed metal has no return path to the chassis the
reading must be infinite.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.
Leakage Current Hot Check (See below Figure)
Plug the AC cord directly into the AC outlet.
Do not use a line Isolation Transformer during this check.
Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC voltmeter
with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC voltage
measurements for each exposed metallic part. Any voltage
measured must not exceed 0.75 volt RMS which is corresponds to
0.5mA.
In case any measurement is out of the limits specified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.
Leakage Current Hot Check circuit
The source of X-RAY RADIATION in this TV receiver is the High
Voltage Section and the LCD PANEL.
For continued X-RAY RADIATION protection, the replacement
panel must be the same type panel as specified in the
Replacement Parts List.
1.5 Kohm/10W
To Instrument's
exposed
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter
IMPORTANT SAFETY NOTICE
0.15uF

CAUTION: Before servicing receivers covered by this service
manual and its supplements and addenda, read and follow the
SAFETY PRECAUTIONS on page 3 of this publication.
NOTE: If unforeseen circumstances create conflict between the
following servicing precautions and any of the safety precautions on
page 3 of this publication, always follow the safety precautions.
Remember: Safety First.
General Servicing Precautions
1. Always unplug the receiver AC power cord from the AC power
source before;
a. Removing or reinstalling any component, circuit board
module or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical plug or
other electrical connection.
c. Connecting a test substitute in parallel with an electrolytic
capacitor in the receiver.
CAUTION: A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an
explosion hazard.
2. Test high voltage only by measuring it with an appropriate high
voltage meter or other voltage measuring device (DVM,
FETVOM, etc) equipped with a suitable high voltage probe.
Do not test high voltage by "drawing an arc".
3. Do not spray chemicals on or near this receiver or any of its
assemblies.
4. Unless specified otherwise in this service manual, clean
electrical contacts only by applying the following mixture to the
contacts with a pipe cleaner, cotton-tipped stick or comparable
non-abrasive applicator; 10% (by volume) Acetone and 90% (by
volume) isopropyl alcohol (90%-99% strength)
CAUTION: This is a flammable mixture.
Unless specified otherwise in this service manual, lubrication of
contacts in not required.
5. Do not defeat any plug/socket B+ voltage interlocks with which
receivers covered by this service manual might be equipped.
6. Do not apply AC power to this instrument and/or any of its
electrical assemblies unless all solid-state device heat sinks are
correctly installed.
7. Always connect the test receiver ground lead to the receiver
chassis ground before connecting the test receiver positive
lead.
Always remove the test receiver ground lead last.
8. Use with this receiver only the test fixtures specified in this
service manual.
CAUTION: Do not connect the test fixture ground strap to any
heat sink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid-state) devices can be damaged easily
by static electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some field-effect transistors and
semiconductor "chip" components. The following techniques
should be used to help reduce the incidence of component
damage caused by static by static electricity.
1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any electrostatic
charge on your body by touching a known earth ground.
Alternatively, obtain and wear a commercially available
discharging wrist strap device, which should be removed to
prevent potential shock reasons prior to applying power to the
unit under test.
2. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as
aluminum foil, to prevent electrostatic charge buildup or
exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES
devices.
4. Use only an anti-static type solder removal device. Some solder
removal devices not classified as "anti-static" can generate
electrical charges sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate
electrical charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective
package until immediately before you are ready to install it.
(Most replacement ES devices are packaged with leads
electrically shorted together by conductive foam, aluminum foil
or comparable conductive material).
7. Immediately before removing the protective material from the
leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be
installed.
CAUTION: Be sure no power is applied to the chassis or circuit,
and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Otherwise harmless motion such as
the brushing together of your clothes fabric or the lifting of your
foot from a carpeted floor can generate static electricity
sufficient to damage an ES device.)
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and appropriate
tip size and shape that will maintain tip temperature within the
range or 500 F to 600 F.
2. Use an appropriate gauge of RMA resin-core solder composed
of 60 parts tin/40 parts lead.
3. Keep the soldering iron tip clean and well tinned.
4. Thoroughly clean the surfaces to be soldered. Use a mall wire-
bristle (0.5 inch, or 1.25cm) brush with a metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal temperature.
(500 F to 600 F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static, suction-
type solder removal device or with solder braid.
CAUTION: Work quickly to avoid overheating the
circuitboard printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal temperature
(500 F to 600 F)
b. First, hold the soldering iron tip and solder the strand against
the component lead until the solder melts.
c. Quickly move the soldering iron tip to the junction of the
component lead and the printed circuit foil, and hold it there
only until the solder flows onto and around both the
component lead and the foil.
CAUTION: Work quickly to avoid overheating the circuit
board printed foil.
d. Closely inspect the solder area and remove any excess or
splashed solder with a small wire-bristle brush.
SERVICING PRECAUTIONS

IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong) through
which the IC leads are inserted and then bent flat against the
circuit foil. When holes are the slotted type, the following technique
should be used to remove and replace the IC. When working with
boards using the familiar round hole, use the standard technique
as outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation by gently
prying up on the lead with the soldering iron tip as the solder
melts.
2. Draw away the melted solder with an anti-static suction-type
solder removal device (or with solder braid) before removing the
IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad and
solder it.
3. Clean the soldered areas with a small wire-bristle brush.
(It is not necessary to reapply acrylic coating to the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by clipping its leads as close as
possible to the component body.
2. Bend into a "U" shape the end of each of three leads remaining
on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the corresponding
leads extending from the circuit board and crimp the "U" with
long nose pliers to insure metal to metal contact then solder
each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the circuit
board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as
possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit
board.
3. Observing diode polarity, wrap each lead of the new diode
around the corresponding lead on the circuit board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of
the two "original" leads. If they are not shiny, reheat them and if
necessary, apply additional solder.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board hollow
stake.
2. Securely crimp the leads of replacement component around
notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the replaced
component and adjacent components and the circuit board to
prevent excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board causing the foil to separate from or "lift-off" the board. The
following guidelines and procedures should be followed whenever
this condition is encountered.
At IC Connections
To repair a defective copper pattern at IC connections use the
following procedure to install a jumper wire on the copper pattern
side of the circuit board. (Use this technique only on IC
connections).
1. Carefully remove the damaged copper pattern with a sharp
knife. (Remove only as much copper as absolutely necessary).
2. carefully scratch away the solder resist and acrylic coating (if
used) from the end of the remaining copper pattern.
3. Bend a small "U" in one end of a small gauge jumper wire and
carefully crimp it around the IC pin. Solder the IC connection.
4. Route the jumper wire along the path of the out-away copper
pattern and let it overlap the previously scraped end of the good
copper pattern. Solder the overlapped area and clip off any
excess jumper wire.
At Other Connections
Use the following technique to repair the defective copper pattern
at connections other than IC Pins. This technique involves the
installation of a jumper wire on the component side of the circuit
board.
1. Remove the defective copper pattern with a sharp knife.
Remove at least 1/4 inch of copper, to ensure that a hazardous
condition will not exist if the jumper wire opens.
2. Trace along the copper pattern from both sides of the pattern
break and locate the nearest component that is directly
connected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead of the
nearest component on one side of the pattern break to the lead
of the nearest component on the other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is dressed so the
it does not touch components or sharp edges.

1. Application range
This specification is applied to ML-041B chassis.
2. Requirement for Test
Testing for standard of each part must be followed in below
condition.
(1) Temperature: 25°C ± 2°C
(2) Humidity: 65% ± 10%
(3) Power: Standard input voltage (AC 100-240V, 50/60Hz)
(4) Measurement must be performed after heat-run more than
30min.
(5) Adjusting standard for this chassis is followed a special
standard.
SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement .
3.General Specification
1
2
3
Maker
Type
ActiveDisplay Area
Pixel Pitch [mm]
Electrical Interface
Color Depth
Size [mm]
Surface Treatment
Operating Mode
Back light Unit
R/T Typ.
Maker
Type
ActiveDisplay Area
Pixel Pitch [mm]
Electrical Interface
Color Depth
Size [mm]
Surface Treatment
Operating Mode
Back light Unit
R/T Typ.
Maker
Type
ActiveDisplay Area
Pixel Pitch [mm]
Electrical Interface
Color Depth
Size [mm]
Surface Treatment
Operating Mode
Back light Unit
R/T Typ.
LPL
TFT Color LCD Module
20.1 inches(380.16mm) diagonal(Aspect 4:3)
0.6375mm(H)x0.6375mm(V)xRGB
TTL
8BIT, 16,777,216 colors
450(H)x 348.7(V)x20(D)
Glare, Hard Coating(3H)
Normally Black
6 CCFL(6 lamps)
16ms(R.T.:7/10ms + F.T.:18/20ms)
AUO
TFT Color LCD Module
20.1 inches(510.00mm) diagonal
0. 6376mm(H)x0.6375mm(V)xRGB
TTL
8-BIT 16,777.216 Colors
434(H)x331.6(V)x29.6(D)
Hard Coating, AR,Glare (3H)
Normally Black
6 CCFL(6 lamps)
16ms
CMO
TFT Color LCD Module
20.1 inches(510.00mm) diagonal
0. 6375mm(H)x0.6375mm(V)xRGB
TTL
8-BIT 16,777.216 Colors
448(H)x339.6(V)x25(D)
Anti Glare, Hard Coating(3H)
Normally Black
6 CCFL(6 lamps)
16ms(R.T.:5/7ms + F.T.:11/14ms)
Item Specification Remark
No.
LPL
AUO
CMO

4. Feature and Function
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Teletext
REMOCON
CVBS VIDEO Input
S-VIDEO Input
Component input
PERI TV Connector
H/p input
RS-232
Discrete IR
2 Carrier Stereo
NICAM Stereo
2 Carrier Dual
NICAM Dual
DW(Double Window) Mode
MW(Multi Window) Mode
Film Mode
Noise Reduction
Progressive Scan
Motion Detection
SRS WOW
wivel Speaker
Ez-pip
ARC
DRP
DCDI
HDCP
TOP, FLOF
NEC Code
1
1
1
Full SCART : 1
1
NO
NO
BG, DK
BG, I, LL'
BG, DK
BG, I, LL'
X
X
O
X
O
X
X
X
X
O
O
X
X
Item Specification Remark
No.
Top(option)
PAL/ NTSC
Rear
Rear
Rear (option, NT)
Rear (option,EU)
Rear
5.Optical Character
Item RemarkSpecification
Viewing Angle
<CR 10>
Luminance
Contrast Ratio
CIE Color Coordinates
Typical
MAX/MIN
ALL white/All black
R/L,
U/D
Luminance(cd/ )
Variation
LPL
85/85
85/85
400
1.3
400
0.289
0.335
0.692
0.335
0.289
0.583
0.143
0.909
WHITE
RED
Green
Blue
WX
WY
Wr
Yr
Xg
Yg
Xb
Yb
Typ.
Typ.
Typ.
Typ.
Typ.
Typ.
Typ.
Typ.
CMO
80/80
75/65
450
1.3
500
0.285
0.293
0.692
0.332
0.276
0.601
0.142
0.075
CMO
85/85
90/90
450
1.3
600
0.31
0.33
0.64
0.34
0.29
0.61
0.14
0.07
No.
1
2
3
4

6.Engineering Specification
1
2
3
4
5
Power Supply
Normal
Stand By
Suspend Mode
DPM Off Mode
Cut-off Switch off
ITEM
D-SUB Pin Configuraion
Control Function
Comoponent Jack
D4 Jack
(525i, 525p, 750p, 1125i)
H/V Sync
On/On
Off/On
On/Off
Off/Off
-
Spectification
1: RED
3: Blue:
5: S.T(GND)
7: Green GND
9: N.C
11: ID0(GND)
13: H-Sync
15: SCL
1) Contrast/Brightness
2) H-Position/V-Position
3) Tracking : Clock/ Phase
4) Auto Configure
RESET
1: Y
3: Pb
5: Pr
1: Y GND
2: Pb
5: Pr
7: LINE1 Ready
9: Line2
11: Line3
13: Line3 ready
2: Green
4: ID2(GND)
6: RED GND
8: Blue GND
10: D-GND
12: SDA
14: V-Sync
Shell: GND
2: Y GND
4: Pb GND
6: Pr GND
8: LINE1
10: Line2 Ready
12: SWITCH GND
14: SWITCH
Remark
10: Digital GND
Middle east/
NTSC Area
JAPAN Only
Video
Active
Off
-
Power Consumption
65W
1W
1W
1W
0W
PBP SWAP ON/OFF
Item Specification Remark
No.
LED Color
GREEN
LED
OFF

6-2.Power
NO
1
2
3
4
5
6
7
8
9
10
11
AC Power Shut Down Voltage
DC Voltage, Inverter
DC Voltage, LCD Panel
DC Voltage, Audio
DC Voltage, Tuner(5)
DC Voltage, Tuner(9)
DC Voltage, Tuning(31)
DC Voltage, VCTi(5)
DC Voltage, VCTi(8)
DC Voltage, VCTi(3.3)
DC Voltage, VCTi(1.8)
DC Voltage, GM2221 (3.3)
DC Voltage, GM2221 (1.8)
DC Voltage, Digital (3.3)
DC Voltage, Digital (5)
90
22.8
11.4
14.0
4.5
8.5
31
4.5
7.5
3.1
1.6
3.1
1.6
2.8
4.5
24
12
15
5
9
33
5
8
3.3
1.8
3.3
1.8
3.3
5
264
25.2
12.6
16.0
5.5
9.5
35
5.5
8.5
3.5
2.0
3.5
2.0
3.8
5.5
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
Japan only
Item Min Typ Max Unit Remark
6-3. External Interface
NO
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Video Input Level
Audio Input Level
Audio Input Frequency Response
Audio Input S/N
Audio Input Distortion
Audio Input Dynamic Range
Video Output Level
Video Output Frequency Response
Video Output S/N
Audio Output Level
Audio Output Frequency Response
Audio Output S/N
Audio Output Distortion
Video Input Level, R/G/B
Video Input Level, Component(Y, PB, PR)
RGB Input Resolution, Vertical
RGB Input Resolution, Horizontal
RGB Input Horizontal Frequency
RGB Input Frame Rate
0.85
0.4
0.1
40
2
0.85
3.8
40
0.4
0.1
40
0.6
0.6
1
0.5
1
0.5
0.7
0.7
768
1280
1.15
0.6
7
2
1.15
0.6
7
2
0.8
0.8
Vpp
V
KHz
DB
%
V
Vpp
MHz
DB
V
KHz
DB
%
Vpp
Vpp
Pixel
Pixel
KHz
Hz
EN-50049
NTSC:0.4Vrms(Typ)
75 ohm
75 ohm
Only 20" 640 Pixel
480
See table 5-5
See table 5-5
Item Min Typ Max Unit Remark
6-4. The Others
NO
1
2
3
4
5
6
Search Sensitivity
Soft Ware Functionality Test
REMOCON Working Sensitivity, Straight
REMOCON Working Sensitivity, T/B/L/R
Closed Caption Sensitivity
Teletext Sensitivity
0.1
0.1
-85
10
9
-70
-70
dBm
m
m
dBm
dBm
LGE Specification
30 degree
NTSC ONLY
Item Min Typ Max Unit Remark

1. Application Object
This instruction is for the application to the LCD TV.
2. Adjustment
2.1 Adjustment overview
The unit is set to automatically adjust using the
factory automation equipment. However when errors
occur, it should be adjusted manually.
2.2 Auto Gain/Offset adjustment
2.2.1 RF Mode adjustment
2.2.1.1 Adjustment preparation
Conduct Heat Run at the RF fog signals for more than
30 minutes.
2.2.1.2 Auto Gain/Offset adjustment
Press IN-START Key to convert to the adjustment
mode using the adjustment (SVC) remote controller,
and press VOL+ Key at the Auto Gain menu.
(In case of RM-20LA70, press IN-START Key twice)
Once the adjustment is completed, press the Enter
Key to save and finish the adjustment.
2.2.2 Component Mode adjustment
2.2.2.1 Adjustment preparation
Conduct Heat Run at the RF fog signals for more than
30 minutes.
Connect the Pattern Generator to the Component
Jack (Y, Pb, Pr) of LCD TV.
2.2.2.2 Auto Gain/Offset adjustment
Convert the input mode to the component input.
Using the Pattern Generator (801GF, VG819) adjust
480P for resolution and Color Bar
signals for patterns. Or adjust Color Bar signals in
accordance with VG819.
Press the IN-START Key to convert into the
adjustment mode using the adjustment (SVC) remote
controller, and press VOL+ Key at the Auto Gain
menu.
Once the adjustment is completed, press the Enter
Key to save and finish the adjustment
ADJUSTMENT INSTRUCTION

SVC REMOCON
1 POWER
2 POWER ON
3 MUTE
4 P-CHECK
5 S-CHECK
6 ARC
7 CAPTION
8 TXT
9 TV/AV
10 TURBO SOUND
11 TURBO PICTURE
12 IN-START
13 ADJ
14 MPX
15 EXIT
16 APC(PSM)
17 ASC(SSM)
18 MULTIMIDIA
19 FRONT-AV
20 CH
21 VOL
22 ENTER
23 PIP CH-(OP1)
24 PIP CH+(OP2)
25 PIP SWAP(OP3)
26 PIP INPUT(OP4)
27 EYE
28 MENU
29 IN-STOP
30 STILL
31 TIME
32 SIZE
33 MULTI PIP
34 POSITION
35 MODE
36 PIP
37 TILT
38 0~9
To turn the TV on or off
To turn the TV on automatically if the power is supplied to the TV. (Use the
POWER key to deactivate): It should be deactivated when delivered.
To activate the mute function.
To check TV screen image easily.
To check TV screen sound easily
To select size of the main screen (Normal, Spectacle, Wide or Zoom)
Switch to closed caption broadcasting
To toggle on/off the teletext mode
To select an external input for the TV screen
To start turbo sound
To start turbo picture
To enter adjustment mode when manufacturing the TV sets.
To adjust the screen voltage (automatic):
In-start mute Adjust AV(Enter into W/B adjustment mode)
W/B adjustment (automatic):
After adjusting the screen W/B adjustment Exit two times (Adjustment completed)
To enter into the adjustment mode. To adjust horizontal line and sub-brightness.
To select the multiple sound mode (Mono, Stereo or Foreign language)
To release the adjustment mode
To easily adjust the screen according to surrounding brightness
To easily adjust sound according to the program type
To check component input
To check the front AV
To move channel up/down or to select a function displayed on the screen.
To adjust the volume or accurately control a specific function.
To set a specific function or complete setting.
To move the channel down in the PIP screen.
To use as a red key in the teletext mode
To move the channel in the PIP screen
To use as a green key in the teletext mode
To switch between the main and sub screens
To use as a yellow key in the teletext mode
To select the input status in the PIP screen
To use as a blue key in the teletext mode
To set a function that will automatically adjust screen status to match
the surrounding brightness so natural color can be displayed.
To select the functions such as video, voice, function or channel.
To set the delivery condition status after manufacturing the TV set.
To halt the main screen in the normal mode, or the sub screen at the PIP screen.
Used as a hold key in the teletext mode (Page updating is stopped.)
Displays the teletext time in the normal mode
Enables to select the sub code in the teletext mode
Used as the size key in the PIP screen in the normal mode
Used as the size key in the teletext mode
Used as the index key in the teletext mode (Top index will be
displayed if it is the top text.)
To select the position of the PIP screen in the normal mode
Used as the update key in the teletext mode (Text will be
displayed if the current page is updated.)
Used as Mode in the teletext mode
To select the simultaneous screen
To adjust screen tilt
To manually select the channel.
Shortcut keys
Shortcut keys
Shortcut keys
Use the AV
key to enter
the screen
W/B
adjustment
mode.
Shortcut keys
Shortcut keys
Shortcut keys

TROUBLESHOOTING
No power
(LED indicator off)
Check short of main B/D
or Change Lips
Change IC1107, IC1104
Change LED Assy
Check 15V or 5V
of Lips
Check Output of
IC1107, IC104
Check LED Assy
Check P1100, P210 Connector
Fail
Fail
Change Q1100
Check Output of
Q1100 Fail
Pass
Fail
Pass
Pass
Pass
:[A]Process

No Raster
Check LED Status
on display unit
Check the input/
Output of IC901
Check L900,L901
L902,L903
Check inverter
Connector or inverter
Check input source cable and jack
Repeat A PROCESS
Fail
Change L900,L901,
L902,L903
Fail
Change IC901
Fail
Change inverter
connector or inverter
Fail
Change panel link
cable or module
Fail
Change module
Fail
Check panel link
Cable or module
Pass
Pass
Pass
Pass
:[B]Process

No Raster on Component signal
Check JA1200 or
RCA CABLE
Check the signal of
L1200, L1202, L1203
Repeat
[A] Process
Check the input/
output of IC1
Check the input/
output of IC901
Check input source cable and jack
Fail
Re-soldering or
Change the defect part,
Check X11
Fail
Re-soldering or
Change the defect part,
Check X900
Fail
Pass
Pass
Pass
Check the input/output
of IC800, IC851 Re-soldering or
Change the defect part
Fail
Pass

No Raster on AV Signal
(Video, S-Video) No Raster on TV(RF) signal
Change L1209, L1210,
L1212
Check the signal of
L1209, L1210, L1212
Repeat
[A] Process Check the output of
TU1000
Check the input/output
of IC1
Check the input/output
of IC800, IC851
Check input source cable and jack
Fail
Fail Fail
Fail
Re-soldering or
Change the defect part
Chek X11
Fail Re-soldering or
Change the defect part
Check 5V, 33V of TU1000
Re-soldering or
Change the defect part
Pass
Pass
Pass
Check the input/output
of IC901 Fail
Re-soldering or
Change the defect part
Check X900
Pass
Pass

No Sound
Check the speaker wire
Change source input
Check the
input source Fail
Pass
Re-soldering or
Change the defect part
Check X11
Check the input/output
of IC1 Fail
Pass
Re-soldering or
Change the defect part
Check the input/output
of IC100,IC101 Fail
Pass
Change speaker
Check the speaker Fail
Pass

BLOCK DIAGRAM
Tuner
TU1000
VCTI
IC1
GM2221
IC901
AT49F
IC905
SM5301BS IC800
IC100 IC101
Audio Amp
AC IN
M52758FP
IC851
LA7222 IC2
TC90A65F
IC500
14066
IC202
D-SUB
AT24C16
IC4
DIGITAL SIGNAL
SOUND INPUT
IF +,- INPUT
ANALOG SIGNAL
SOUND OUTPUT
ML-041B Block Diagram
POWER
IF+,-
PC
SIDE_AV
L, R
SIDE_L,R
PC L,R
L,R AUDIO
S
A
W
Z1000
SCART V,L,R
S-VHS
H/P V
SCART R,G,B
SIDE V
YP
bPr
RGB OUT
TTL 1 OUT
TTL 2 OUT
LVDS1 OUT
PC RGB
COMPONENT

BLOCK DIAGRAM DESCRIPTION
1. Video Controller Unit & Display Data Conversion Unit
The video controller unit receives the video signals inputted through the tuner, AV port (AV1, AV2, S-Video,
component), and converts them into an analog RGB signal through the microcomputer (VCTI) combined with
the video decoder that integrates various functions in one chip.
Either the analog RGB, component YPbPr or PC RGB signal is selected by the switching IC and inputted to a
scaler (GM2221), which is sent to the LCD module after being modified to an LVDS signal through the
integrated LVDS IC.
Or, it is sent to the LCD module as a TTL output.
VCTi is the main microprocessor that handles video signal processing and sound signal processing. It also
manages the RF signals received from the tuner.
The scaler can control timing to fit into the LCD panel, and can also control the size and position of the input
signal.
2. Power Supply Unit
The power supply unit provides 15V and 5V DC power to the mainboard.
The PWM Step-Up DC/DC Converter circuit is used to generate the 33V used for the tuner.
15V power is directly used by the sound amplifier IC and is also used to generate 5V power through the
regulator. 12V power is used for the LCD panel power, and 5V power is converted to 3.3V and 1.8V power
through the regulator, which in turn supplies electrical power for ICs such as VCTI and scaler.

SPEAKER SPEAKER
LOCAL KEY
IR_LED
11P_2.0MM H-H 100MM
2P_AC_SOCKET
18P_1.0MM FFC 54MM (RZ ONLY)
P1203
P3
P210
6P_2.0MM H-B
600MM
3P_2.5MM H-B
220MM
1. 20P LVDS : 200MM 2. 41P TTL 3. 50P TTL : 145MM
4P_2.5MM SHIELD RECEPTERCLE GND: 2PIN, 4PIN 500MM 750MM
1
6
7
52
34
89
P904 P902 P901
WIRING DIAGRAM
No. Part No.
1 2 3 4 5 6 7 8
Wiring Part List
6631T25019Y 6631T11017P-CMO 6631T11017Q-AUO 6631T11021A 6631T11012R 6631T20028G 6631T20029X 6631T25021A 6620K00007C or 6620K00007A

EXPLODED VIEW
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