LG L1718S Service Manual

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COLOR MONITOR

SERVICE MANUAL

CHASSIS NO. :

MODEL: L1718S

(L1718S-SNQ/L1718S-BNQ.Axx*EP)

xx* means sales region and Module (xxK : INNOLUX, xxB : CPT)

CAUTION

BEFORE SERVICING THE UNIT, READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

*To apply the MSTAR Chip.

SPECIFICATIONS ................................................... 2

PRECAUTIONS ....................................................... 3

TIMING CHART ....................................................... 7

DISASSEMBLY ........................................................ 8

BLOCK DIAGRAM...................................................10

DISCRIPTION OF BLOCK DIAGRAM ................... 11

ADJUSTMENT ...................................................... 13

SPECIFICATIONS

1. LCD CHARACTERISTICS

Type Active Display Area : 17 inch Pixel Pitch Color Depth

Size Electrical Interface : LVDS

Surface Treatment : Hard-coating(3H), Haze=25%

Operating Mode Backlight Unit

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio ≥ 10 (a) For

(b)

2-2. Luminance

(a) For

250cd/m

(b)

2-3. Contrast Ratio (a) For

(b)

Typic al

3. SIGNAL (Refer to the Timing Chart)

3-1. Sync Signal Type :

Separate Sync, Composite, SOG (Sync On Green)

InnoLux 75°(85°)/Right75°(85°);Top 75°(85°) /Bottom60°(70°) at type CR≥10 (CR≥5)

For

CLAA170EA07QG panel: Left 70°(85°)/Right70°(85°);Top 63°(85°)/Bottom67°(85°) at type CR≥10(CR≥5)

InnoLux MT170EN01 V.7 panel: 300cd/m2 (Typ.)

For

CLAA170EA07QG panel: 290cd/m2 (Typ.)

250cd/m

InnoLux MT170EN01 V.7 panel: 500:1 minimum;

700:1 Typical For

CLAA170EA07QG panel: 400:1 minimum; 500:1

MT170EN01 V.7 panel: Left

(Min.) (6500k); 200 cd/m2 (Min.)(9300k)

(Min.) (6500k);200 cd/m2 (Min.)(9300k)

3-2. Video Input Signal

1) Type

2) Voltage Level a) Color 0, 0 b) Color 7, 0 Color 15, 0

3) Input Impedance : 75 Ω

3-3. Operating Frequency

Horizontal Vertical

. Max. Resolution

D-sub Analog

: TFT Color LCD Module

: 0.264 (H) x 0.264 (V) : 16.2M colors

: 358.5 (H) x 296.5 (V) x 17.5(D)

: Normally White, Transmissive mode : Top/Bottom edge side 4-CCFL

(Cold Cathode Fluorescent Lamp)

: R, G, B Analog : 0~0.71 V : 0 Vp-p

: 0.467 Vp-p c)

: 0.714 Vp-p

: 30 ~ 83kHz

56 ~ 75

: 1280 x 1024@75Hz

Anti-Glare treatment

CONTENTS

SERVICE OSD ............................................... .........14

TROUBLESHOOTING GUIDE .............................. 15

WIRING DIAGRAM ............................................... 22

EXPLODED VIEW ................................................... 23

REPLACEMENT PARTS LIST ............................... 24

SCHEMATIC DIAGRAM ......................................... 32

5. POWER SUPPLY

5-1. Power 5-2. Power Consumption

MODE H/V SYNC VIDEO

OWER ON (NORMA

STAND-BY OFF/ON OFF

SUSPEND ON/OFF OFF

DPMS OFF OFF/OFF OFF

POWER S/W Off

6. ENVIRONMENT

6-1. Operating Temperature : 10°C~35°C (50°F~95°F)

6-2. Relative Humidity

6-3. MTBF

7. DIMENSIONS (with Stand)

Width Length Height

8. WEIGHT (with T I LT/SWIVEL)

Net. Weight Gross Weight

: AC 90~264V, 47.5~63Hz , <0.8A

OWER CONSUMPTIONLED COLOR

ON/ON ACTIVE less than 35 W GREEN

(Ambient)

: 10%~80%

(Non-condensing)

Lamp Life

: 50,000 HRS with 90% Confidence : 50,000 Hours(Min)

: 308.4 mm : 376.7 mm :126.1 mm

: 3.7+/-0.3kg : 4.8+/-0.4 kg

less than 1W less than 1W less than 1W

less than 1W

AMBER

Off

PRECAUTION

WARNING FOR THE SAFETY-RELATED COMPONENT.

• There are some special components used in LCD

monitor that are important for safety. These parts are

marked on the schematic diagram and t he replacement parts list. It is essential that these

critical parts should be replaced with the manufacturer’s specified parts to prevent electric shock, fire or other hazard.

• Do not modify original design without obtaining written permission from manufacturer or you will void the original parts and labor guarantee.

TAKE CARE DURING HANDLING THE LCD MODULE WITH BACKLIGHT UNIT.

• Must mount the module using mounting holes arranged in four corners.

• Do not press on the panel, edge of the frame strongly or electric shock as this will result in damage to the screen.

• Do not scratch or press on the panel with any sharp objects, such as pencil or pen as this may result in damage to the panel.

• Protect the module from the ESD as it may damage the electronic circuit (C-MOS).

• Make certain that treatment person’s body are grounded through wrist band.

• Do not leave the module in high temperature and in areas of high humidity for a long time.

• The module not be exposed to the direct sunlight.

• Avoid contact with water as it may a short circuit within the module.

• If the surface of panel become dirty, please wipe it off with a softmaterial. (Cleaning with a dirty or rough cloth may damage the panel.)

CAUTION

Please use only a plastic screwdriver to protect yourself from shock hazard during service operation.

WARNING

BE CAREFUL ELECTRIC SHOCK !

• If you want to replace with the new backlight (CCFL) or inverter circuit, must disconnect the AC adapter because high voltage appears at inverter circuit about 650Vrms.

• Handle with care wires or connectors of the inverter circuit. If the wires are pressed cause short and may burn or take fire.

• Be careful while tilting and rotating the monitor to avoid pinching hand(s)

Leakage Current Hot Check Circuit

AC Volt-meter

Good Earth Ground

To Instrument's exposed METALLIC PARTS

1.5 Kohm/10W

such as WATER PIPE, CONDUIT etc.

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:

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 Precaution s

1. Always unplug the receiver AC power cord from the AC

2. Test high voltage only by measuring it with an

3. Discharge the picture tube anode only by (a) first

4. Do not spray chemicals on or near this receiver or any of

5. Unless specified otherwise in this service manual,

6. Do not defeat any plug/socket B+ voltage interlocks

7. Do not apply AC power to this instrument and/or any of

8. Always connect the test receiver ground lead to the

If unforeseen circumstances create conflict

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.

d. Discharging the picture tube anode.

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".

connecting one end of an insulated clip lead to the degaussing or kine aquadag grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touch the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

its assemblies.

clean electrical contacts only by applying the following mixture to the contacts with a pipe cleaner, cottontipped 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.

with which receivers covered by this service manual might be equipped.

its electrical assemblies unless all solid-state device heat sinks are correctly installed.

receiver chassis ground before connecting the test receiver positive lead. Always remove the test receiver ground lead last.

9. 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 fol l ow in g 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 "antistatic" 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 Guidelin es

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.

IC Remove/Replacemen t

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 Transi stor 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.

distingis

hment

Polo

rity

VIDEO

SYNC

DOT

CLOCK

[MHz]

TIMING CHART

D B

Frequency

[kHz]/ [Hz]

Total period

Display

(E)

(A)

Front Porch

(D)

Sync.

(C)

Back

Porch

(B)

Resolutio

H(Pixels) +

V(Lines) -

H(Pixels) - 31.468 900 720 18 108 54

V(Lines) +

H(Pixels) - 31.469 800 640 16 96 48

V(Lines) -

H(Pixels) - 37.5 840 640 16 64 120

V(Lines) -

H(Pixels) + 37.879 1056 800 40 128 88

V(Lines) +

H(Pixels) + 46.875 1056 800 16 80 160

V(Lines) +

H(Pixels) +/- 49.725 1152 832 32 64 224

V(Lines) +/-

H(Pixels) - 48.363 1344 1024 24 136 160

V(Lines) -

H(Pixels) - 60.123 1312 1024 16 96 176

V(Lines) -

H(Pixels) +/- 68.681 1456 1152 32 128 144

V(Lines) +/-

H(Pixels) +/- 61.805 1504 1152 18 134 200

V(Lines) +/-

H(Pixels) + 63.981 1688 1280 48 112 248

V(Lines) +

H(Pixels) + 79.976 1688 1280 16 144 248

V(Lines) +

25.175

28.321

25.175

31.5

40.0

49.5

57.283

65.0

78.75

100.0

92.978

108.0

135.0

31.469

70.08 449 350 37 2 60

70.09 449 400 12 2 35

59.94 525 480 10 2 33

75 500 480 1 3 16

60.317 628 600 1 4 23

75.0 625 600 1 3 21

74.55 667 624 1 3 39

60.0 806 768 3 6 29

75.029 800 768 1 3 28

75.062 915 870 3 3 39

65.96 937 900 2 4 31

60.02 1066 1024 1 3 38

75.035 1066 1024 1 3 38

800 640 16 96 48

640 x 350

720 X 400

640 x 480

800 x 600

832 x 624

1024 x 768

1152 x 870

1152 x 900

1280 x 1024

DISASSEMBLY

BLOCK DIAGRAM

InnoLux TFT-LCD Module with 4FFCLs

LVDS Transmitter

Inverter +

TSUM16AL-LF

DC12V to DC5V

C Socket

D-sub

C Input

Analog

RGB Signal

MCU

3.3V and

1.8V regulator

24C02

DDC

128KB Fl ash RO M

EEPROM

24C04

OSD parameter

Timing

arameter

Key pad

DESCRIPTION OF BLOCK DIAGRAM

1. Video Controller Part.

This part amplifies the level of video signal for the digital conversion and converts from the analog video signal to the digital video signal using a pixel clock. The pixel clock for each mode is generated by the PLL. The range of the pixel clock is from 25MHz to 135MHz. This part consists of the Scaler, ADC convertor and LVDS transmitter. The Scaler gets the video signal converted analog to digital, interpolates input to 1280 X 1024 resolution signal and outputs 8-bit R, G, B signal to transmitter.

2. Power Part.

This part consists of the one 3.3V, and one 1.8V regulators to convert power which is provided 5V in Power board. 12V is provided for inverter, 12V is provided for LCD panel and 5V for micom. Also, 5V is converted 3.3V and 1.8V by regulator. Converted power is provided for IC in the main board. The inverter converts from DC12V to AC 700Vrms and operates back-light lamps of module.

3. MICOM Part.

This part is include video controller part. And this part consists of EEPROM IC which stores control data, and the Micom which imbedded in scaler IC.

The Micom distinguishes polarity and frequency of the H/V sync are supplied from signal cable. The controlled data of each modes is stored in EEPROM.

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