LG N1642W-PF Owner’s Manual

COLOR MONITOR

SERVICE MANUAL

Website:http://biz.LGservice.com

E-mail:http://www.LGEservice.com/techsup.html

CAUTION

BEFORE SERVICING THE UNIT,

READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS NO. : L M97A

MODEL: N1642W (N1642W-PFT.A***AP*)

( ) **Same model for Service

Internal Use Only

- 2 -

CONTENTS

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

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

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

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

BLOCK DIAGRAM ................................................... 9

DESCRIPTION OF BLOCK DIAGRAM...................11

ADJUSTMENT ...................................................... 12

TROUBLESHOOTING GUIDE .............................. 14

WIRING DIAGRAM ............................................... 18

EXPLODED VIEW...................................................19

REPLACEMENT PARTS LIST ...............................21

SCHEMATIC DIAGRAM ......................................... 25

1. LCD CHARACTERISTICS

Type : TFT Color LCD Module

Active Display Area : 15.6 inch diagonal

Pixel Pitch : 0.252 (H) x 0.252 (V)

Size : 363.8(H) x 215.9(V) x 14.3(D)

Color Depth : 16.7M(8bit + FRC) colors

Electrical Interface : LVDS

Surface Treatment : Anti-Glare, Hard Coating(3H)

Operating Mode : Transmissive mode,Normally White

Backlight Unit : 2 CCFL

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio ≥ 10

Left : -45°(Typ) Right : +45°(Typ)

Top : +20°(Typ) Bottom : +45°(Typ)

2-2. Luminance : 170(Typ) (Typ. ± 30)-sRGB

: 175(min), 230(Typ)-6500K

: 110(min)-9300K

2-3. Contrast Ratio : 400(Min.)

DFC -> 5000 : 1(Typ)

3. SIGNAL (Refer to the Timing Chart)

3-1. Sync Signal

• RGB

Horizontal Freq.

30 - 66 kHz (Automatic)

3-2. Video Input Signal

4. RESOLUTION

5. POWER SUPPLY

5-1. Power Adaptor(Built-in Power)

Input : AC 100-240V~, 50/60Hz, 0.8A

5-2. Power Consumption

6. ENVIRONMENT

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

6-2. Relative Humidity : 10%~80% (Non-condensing)

6-3. MTBF : 50,000 HRS with 90%

Confidence level

Lamp Life : 40,000 Hours (Min)

7. DIMENSIONS (with TILT/SWIVEL)

Width : 381.7 mm (15.03'')

Depth : 198.4 mm (7.81'')

Height : 323.9 mm (12.75'')

8. WEIGHT (with TILT/SWIVEL)

Net. Weight : 2.6 kg (5.78 lbs)

Gross Weight : 3.6 kg (8.0 lbs)

SPECIFICATIONS

MODE

POWER ON (NORMAL)

STAND BY

SUSPEND

DPMS OFF

POWER S/W OFF

H/V SYNC

ON/ON

OFF/ON

ON/OFF

OFF/OFF

POWER CONSUMPTION

less than 22 W(max)

less than 20 W(typ)

less than 1 W

LED COLOR

BLUE

Flicker

OFF

VIDEO

ACTIVE

OFF

Only for training and service purposes

LGE Internal Use Only

Vertical Freq. 57 - 63 Hz (Automatic)

RGB support 60Hz only(except Dos mode)

1440 x 900 (60Hz)

•

X-PORT

1280 x 1024 (60Hz)

1024 x 768 (60Hz)

1280 x 720 (60Hz)

800 x 600 (72Hz)

1360 x 768 (60Hz)

Signal Input 15 pin D-Sub Connector

Input Form RGB Analog

(0.7 Vp-p/ 75 ohm)

Signal Input X-PORT Connector

Input Form X-PORT Signal

•

RGB

•

X-PORT

Max VESA 1360 x 768 @60 Hz

Recommend VESA 1360 x 768 @60 Hz

- 3 -

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 the

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.)

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.

Leakage Current Hot Check Circuit

PRECAUTION

CAUTION

Please use only a plastic screwdriver to protect yourself

from shock hazard during service operation.

1.5 Kohm/10W

To Instrument's

exposed

METALLIC PARTS

Good Earth Ground

such as WATER PIPE,

CONDUIT etc.

AC Volt-meter

Only for training and service purposes

LGE Internal Use Only

- 4 -

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.

d. Discharging the picture tube anode.

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

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.

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

of its assemblies.

5. 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.

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

with which receivers covered by this service manual

might be equipped.

7. 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.

8. 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.

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 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.)

Only for training and service purposes

LGE Internal Use Only

- 5 -

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.

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.

Only for training and service purposes

LGE Internal Use Only

- 6 -

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.

Only for training and service purposes

LGE Internal Use Only

TIMING CHART

- 7 -

VIDEO

SYNC

MODE

H / V

Sync

Polarity

Dot

Clock

Frequency

Total

Period

( E )

Video

Active

Time ( A )

Sync

Duration

( D )

Front

Porch

( C )

Blanking

Time

( B )

Resolution

H(Pixels) - 31.468 900 720 18 108 54

V(Lines) +

28.321

70.08 449 400 12 2 35

720 X 400

H(Pixels) - 31.469 800 640 16 96 48

V(Lines) -

25.175

59.94 525 480 10 2 33

640 x 480

H(Pixels) + 37.879 1056 800 40 128 88

V(Lines) +

40.0

60.317 628 600 1 4 23

800 x 600

H(Pixels) - 48.363 1344 1024 24 136 160

V(Lines) -

65.0

60.0 806 768 3 6 29

1024 x 768

H(Pixels) + 47.712 1792 1360

64 112 256

V(Lines)

85.5

60.015

795

768 3

1360 x 768

Only for training and service purposes

LGE Internal Use Only

- 8 -

DISASSEMBLY

Pull the cabinet upwards,

Then push the button ”push” to separate

the hinge body and stand body.

Disassemble the back cover.

Separate the lamp shield from rear shield.

Please pull off the latch first.

Pull the cabinet upwards,

Then separate all latches on each side.

Remove the control button from cabinet,

Then disassemble the connector.

# 1

# 4

Turn around the base lock to open the

lock between base cover and stand body..

# 6

# 2

# 3

# 5

Then separate stand body and base cover.

# 7

Only for training and service purposes

LGE Internal Use Only

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