LG W1742S Schematic

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

COLOR MONITOR

SERVICE MANUAL

MODEL: W1742S (W1742S-PFT. A**TAPH for HSD

B00&B01)

**Sales Market

CAUTION

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

*To apply the MSTAR Chip.

http://www.wjel.net

- 1 -

CONTENTS

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

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

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

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

BLOCK DIAGRAM...................................................11

DISCRIPTION OF BLOCK DIAGRAM .................. 13

ADJUSTMENT ...................................................... 15

SPECIFICATIONS

1. LCD CHARACTERISTICS

Type : TFT Color LCD Module
Active Display Area : 17.0 inch
Pixel Pitch : 0.285 (H) x 0.285 (V)
Color Depth : 6bits, 16.2M colors
Size : 389.2 (H) x 254.5 (V) x 11.5(D)
Electrical Interface : FFC
Surface Treatment : Hard-coating(3H), Anti-Glare
Operating Mode : Normally White, Transmissive mode
Backlight Unit : 2-CCFL

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio > 10
Left : 80°min., 85°(Typ) Right : 80°min,85°(Typ)
Top :85° min., 85°(Typ) Bottom : 65°min,85°(Typ)

2-2.Luminance :220(min), 300(Typ) (Full White pattern, 0.7V) -6500K

:170(min) (Full White pattern, 0.7V) -9300K

2-3. Contrast Ratio : 500(min), 600(Tye)

3. SIGNAL (Refer to the Timing Chart)

3-1. Sync Signal

• Type : Separate Sync, SOG

3-2. Video Input Signal

1) Type : R, G, B Analog

2) Voltage Level : 0~0.71 V
a) Color 0, 0 :0 Vp-p
b) Color 7 .0 :0.467Vp-p
c) Color 15, 0 : 0.714Vp-p

3) Input Iwpedance: 75 Ω

3-3. Operating Frequency
Horizontal : 30 ~ 83kHz
Vertical : 56 ~ 75Hz

4. Max. Resolution

D-sub Analog : 1440X900@75Hz

5. POWER SUPPLY

5-1. Power : AC 90~264V, 47.5/63Hz , 3.5Ma

5-2. Power Consumption

(NORMAL)
STAND-BY

SUSPEND ON/OFF OFF less than 1 W AMBER

S/W OFF

6. ENVIRONMENT

6-1. Operating Temperature : 0°C~40°C(Ambient)
6-2. Relative Humidity : 20%~80% (Non-condensing)
6-3. MTBF : 70,000 HRS with 90% Confidence
Lamp Life : 50,000 Hours(Min)

7. DIMENSIONS (with Stand)

Width : 40.49 cm (15.94 inches)
Depth : 19.84 cm (7.81 inches)
Height : 34.98 cm (13.77 inchs)

8. WEIGHT (excl. packing)

Net. Weight : 3kg (6.61 Ibs)

SERVICE OSD ........................................................16

TROUBLESHOOTING GUIDE .............................. 17

WIRING DIAGRAM ............................................... 23

EXPLODED VIEW...................................................24

REPLACEMENT PARTS LIST ...............................26

SCHEMATIC DIAGRAM............................... .......... 35

MODE

POWER

ON

DPMS

OFF

POWER

H/V

SYNC

ON/ON

OFF/ON

OFF/OFF OFF less than 1 W AMBER

- - less than 1 W OFF

VIDEO

ACTIVE

OFF

POWER

CONSUMPTION

21W(typical)

less than 1 W

LED

COLOR

BLUE

AMBER

http://www.wjel.net

- 2 -



http://www.wjel.net

- 3 -



http://www.wjel.net

- 4 -



http://www.wjel.net

- 5 -



http://www.wjel.net

- 6 -



http://www.wjel.net

- 7 -



DISASSEMBLY-Set

#1

Put the monitor on a soft flat.

#3

#2

Pull out the hinge cover as arrow direction.

#4

Remove the three screws.

#5

http://www.wjel.net

Put the front face down, disassembly back cover.

Put the front cover upward. Then let the all latches

are separated.

#6

Pull the key board out of bezel.

- 8 -

#7



＃8

Disassembly the bezel.

#9

Remove the screw.

#11

Disassembly the connector and screw.

#10

Disassemble the LVDS cable

#12

Main board and power board

http://www.wjel.net

The panel

- 9 -



DISASSEMBLY-Stand

#1

#3

Pull the Base Latches to inside until losing elasticity.

#2

Consequently, pull the stand body directly.

#4

Separate Stand Body & Stand Base.

#5

http://www.wjel.net

Separate the hinge and stand.

Fix Stand Base & Stand Body.

- 10 -



BLOCK DIAGRAM

http://www.wjel.net

- 11 -

Power



BLOCK DIAGRAM-POWER

100~240V

Inverter

EMI filter

12V

5V/12V

output OVP

Push-pull

circuit

Rush

prevention

Rectification

Feedback

control

circuit

Transformer

conversion

Starting

resistor

Transformer

Switching

circuit (PWM

control IC &

MOSFER)

LC resonance

Diode

rectifier



OVP protect

circuit

5V

12V

ON/OFF

ON/OFF circuit

DIM

DIM circuit

VDDA

PWM IC

OZ9938GN

OVP circuit

Feedback

circuit

2 CCFL lamps

Sampling

Lamp open

protection

http://www.wjel.net

- 12 -