Lcd Tv Service Manual


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LCD TV SERVICE MANUAL
CHASSIS : AL-04DA
MODEL : 26LX2D-UA
CAUTION
BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CONTENTS
CONTENTS .............................................................................................. 2 PRODUCT SAFETY ..................................................................................3 SPECIFICATION ........................................................................................6 ADJUSTMENT INSTRUCTION ...............................................................10 SVC REMOCON ......................................................................................12 TROUBLE SHOOTING ............................................................................13 BLOCK DIAGRAM...................................................................................16 WIRING DIAGRAM ..................................................................................18 EXPLODED VIEW .................................................................................. 19 EXPLODED VIEW PARTS LIST ..............................................................20 REPLACEMENT PARTS LIST ............................................................... 21 SVC. SHEET ...............................................................................................
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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
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.
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 1MΩ and 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
AC Volt-meter

To Instrument's exposed METALLIC PARTS

0.15uF

Good Earth Ground such as WATER PIPE, CONDUIT etc.

1.5 Kohm/10W

-3-

SERVICING PRECAUTIONS

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 wirebristle (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.

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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.

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SPECIFICATION
NOTE : Specifications and others are subject to change without notice for improvement.

1. Application range
This specification is applied to AL-04DA chassis.

3. Test and Inspection Method
3.1 Performance : LGE TV test method followed.

2. Requirement for Test
Testing for standard of each part must be followed in below condition.

3.2 Demanded other specification. EMI : FCC Class B, IC Class B SAFETY : UL1492, CSA, C22, No.1

(1) Temperature: 20°C ± 5°C (2) Humidity : 65 ± 10% (3) Power: Standard input voltage (AC 110-240V, 50/60Hz)
*Standard Voltage of each product is marked by models (4) Specification and performance of each parts are followed
each drawing and specification by part number in accordance with BOM (5) The receiver must be operated for about 20 minutes prior to the adjustment.

4. General Specification

No

Item

1. Receiving System

2. Available Channel

3. Input Voltage 4. Market 5. Screen Size 6. Aspect Ratio 7. Tuning System 8. LCD Module 9. Operating Environment
10. Storage Environment

Specification ATSC/64 & 256 QAM/ NTSC-M 1) VHF : 02~13 2) UHF : 14~69 3) DTV : 02-69 4) CATV : 01~135 5) CADTV : 01~135 1) AC 100 ~ 260V 50/60Hz NORTH AMERICA 26 inch Wide 16:9 FS LC260WX2-SL03 (1366 x 768) 1) Temp : 0 ~ 40 deg 2) Humidity : ~ 80 % 1)Temp : -20 ~ 60 deg 2) Humidity : 0 ~ 90 %

Remark LPL

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5. External Input Format Component Video Input (Y, CB/PB, CR/PR)

No

Resolution

1 640 x 480

2 704 x 480

3 1280 x 720

4 1280 x 720

5 1920 x 1080

6 1920 x 1080

H-freq(kHz) 15.73 31.47 45.00 44.96 33.75 33.72

V-freq.(kHz) 60 59.94 60.00 59.94 60.00 59.94

Pixel clock

Proposed SDTV ,DVD 480I SDTV 480P HDTV 720P HDTV 720P HDTV 1080I HDTV 1080I

RGB Iinput (PC/DTV)

No

Resolution

PC

1 640 x 350

2 640 x 350

3 720 x 400

4 720 x 400

5 640 x 480

6 640 x 480

7 640 x 480

8 640 x 480

9 800 x 600

10 800 x 600

11 800 x 600

12 800 x 600

13 800 x 600

14 1024 x 768

15 1024 x 768

16 1024 x 768

DTV

17 704 x 480

18 1280 x 720

19 1280 x 720

20 1920 x 1080

21 1920 x 1080

H-freq(kHz)

V-freq.(Hz)

Pixel clock(MHz)

Proposed

31.468 37.861 31.469 37.927 31.469 37.861 37.500 43.269 35.156 37.879 48.077 46.875 53.674 48.363 56.476 60.023

70.09 85.08 70.08 85.03 59.94 72.80 75.00 85.00 56.25 60.31 72.18 75.00 85.06 60.00 70.06 75.02

25.17 31.50 28.32 35.50 25.17 31.50 31.50 36.00 36.00 40.00 50.00 49.50 56.25 65.00 75.00 78.75

EGA EGA DOS DOS VESA(VGA) VESA(VGA) VESA(VGA) VESA(VGA) VESA(SVGA) VESA(SVGA) VESA(SVGA) VESA(SVGA) VESA(SVGA) VESA(XGA) VESA(XGA) VESA(XGA)

31.47 45.00 44.96 33.75 33.72

59.94 60.00 59.94 60.00 59.94

SDTV 480P HDTV 720P HDTV 720P HDTV 1080I HDTV 1080I

DDC O O O O O O O O O O O O O O O O

-7-

HDMI Input (PC/DTV)

No

Resolution

1 PC

2 640 x 480

3 640 x 480

4 640 x 480

5 800 x 600

6 800 x 600

7 800 x 600

8 800 x 600

9 1024 x 768

10 1024 x 768

11 1024 x 768

DTV

12 720 x 480

13 720 x 480

14 1280 x 720

15 1280 x 720

16 1920 x 1080

17 1920 x 1080

H-freq(kHz)

V-freq.(Hz)

Pixel clock(MHz)

Proposed

DDC

31.469

59.94

25.17

VESA(VGA)

O

37.861

72.80

31.50

VESA(VGA)

O

37.500

75.00

31.50

VESA(VGA)

O

35.156

56.25

36.00

VESA(SVGA)

O

37.879

60.31

40.00

VESA(SVGA)

O

48.077

72.18

50.00

VESA(SVGA)

O

46.875

75.00

49.50

VESA(SVGA)

O

48.363

60.00

65.00

VESA(XGA)

O

56.476

70.06

75.00

VESA(XGA)

O

60.023

75.02

78.75

VESA(XGA)

O

31.500

60

27.03

SDTV 480P

O

31.469

59.94

27.00

SDTV 480P

O

45.000

60.00

74.25

HDTV 720P

O

44.955

59.94

74.175

HDTV 720P

O

33.750

60.00

74.175

HDTV 1080I

O

33.716

59.94

74.25

HDTV 1080I

O

-8-

6. General spec(Module)

No Item

1 Active Screen Size

2 Outline Dimension

3 Pixel Pitch

4 Pixel Format

5 Color Depth

6 Luminance ,White

7 Viewing Angle (CR>10)

8 Power Consumption

9 Weight

10 Display Operating Mode

11 Surface Treatment

12 Altitude

Operating

Storage/Shipment

13 Lamp Life Time

Min

Typ

Max

600.53(diagonal)

626(H) x 373(V) x 44.1(D)

147.5 x 421.5 x RGB

1366(H)x768(V) RGB stripe arrangement

8bit 16.7

500

R/L 178(Typ),U/P 178(Typ)

71.6

5.0

Transmissive mode ,normally black

Hard coating (3H), Anti-glare treatment

0 - 14,000

0 - 40,000

50,000 (min.)

Unit mm mm
Mbit cd/m2 degree Watt kg
feet feet Hrs

Remark 26.005 inches Typ.
Center 1 point Typ.
4,267.2 m 12,192.0 m 25±2°C

-9-

ADJUSTMENT INSTRUCTION

1. Applicability
These specifications are applicable for all PDP TV models with an AL-04DA chassis that are manufactured by the Manufacturing Group of the Display Business Division, or any of its related manufacturers.
2. Specifications
2.1 This chassis is the non-charging type chassis for which the power unit is insulated. Therefore, the insulated type transformer is not required but it is recommended that it be used between the power supply line and chassis input side before running the chassis, in order to protect the adjustment equipment.
2.2 Adjustment should be made in the correct sequence. However, the order can be changed for mass production purposes.
2.3 The suggested surrounding temperature is 25±5°C, and suggested relative humidity is 65±10% for the adjustment of the chassis, unless specified.
2.4 The input voltage should be maintained at 110V and 60MHz.

3. Full assembly process adjustment
Each PCB assembly must be checked using the check jig set before the full assembly process. (The power PCB assembly can damage the LCD module irreparably.)
3.1. Extended Display Identification Data (EDID) and Display Data Channel (DDC) download
3.1.1 Overview Developed by VESA, the EDID function is designed to support the "plug & play" function, which enables the computer to configure the user environment automatically through communication with the monitor.
3.1.2 Entering the HDMI EDID Data 1) Equipment
- PC and DDC adjustment jig (PC serial to D-sub connection device)
- DDC recording software (EDID data write & read) - D-Sub terminal - Need separate HDMI cable connection jig.

2.5 The receiver should run for about 15 minutes before starting adjustment, unless specified.
- Run prior operation after receiving 100% White pattern (06CH). (OR, 9. White Pattern state in Ez-Adjust.)
- How to enter into the White Pattern 1) Press the Power ON key in the adjustment remote
control. 2) Or, press the ADJ key on the adjustment remote
control to enter into Ez-Adjust and select 9. White Pattern using CH +/- key. Then, press the OK ( ) key to display 100% Full White Pattern. * In this mode, the SET can be put on HEAT RUN without a separate signal generator.
Note) If you leave the stop image on for more than 20 minutes, you must be careful because an afterimage will appear on the black level section. (Applies to internal digital pattern (13CH) and cross hatch pattern (09CH) with clear black/white contrast, in particular).

3.2. Adjusting AD9883A-Set
3.2.1. Overview AD9883A-Set adjustment automatically sets the optimal black level, and readjusts the RGB differences in analog -> digital converter. Adjustment is made separately for the component mode and RGB-DTV mode input.
3.2.2. Equipment Adjustment remote control: 801GF (802B, 802F, 802R) or MSPG925FA Pattern Generator(It should support 720P horizontal 100% color bar patter display, and the output level should be accurately corrected to 0.7±0.1Vp-p.)
Adjustment pattern: 720P/60Hz HozBar Pattern (Format No. 217, Pattern No. 65)
3.2.3 Signal input method Connect the component output and RGB D-Sub output of the Pattern Generator to the component 1 and RGB D-Sub jack of the set.

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Lcd Tv Service Manual