ViewSonic VG900b-1, VLCDS24020-2W Service Manual

Service Manual

ViewSonic VG900b-1

(VG900b-1_SM_575-Rev. 1.0-October 2002)

ViewSonic



381 Brea Canyon Road, Walnut, California 91789 USA - [phone]

Model No. VLCDS24020-2W

19” Color TFT LCD Display

Copyright

Copyright ¤ 2002 by ViewSonic Corporation. All rights reserved. No part of this publication may be
reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or
computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical,
manual or otherwise, without the prior written permission of ViewSonic Corporation.

Disclaimer

ViewSonic makes no representations or warranties, either expressed or implied, with respect to the
contents hereof and specifically disclaims any warranty of merchantability or fitness for any particular
purpose. Further, ViewSonic reserves the right to revise this publication and to make changes from time
to time in the contents hereof without obligation of ViewSonic to notify any person of such revision or
changes.

Trademarks

ViewSonic is a registered trademark of ViewSonic Corporation.
All other trademarks used within this document are the property of their respective owners.

Revision History

Revision Date Description Of Changes Approval

1a 10/2/02 Initial Reversion DCN-2351 K.Yang

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1b 11/11/02 Revise DCN-2351 C.Shen

TABLE OF CONTENTS

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1.

PRECAUTIONS AND NOTICES...............................................................................1

2.

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

3.

LOCATION OF CONTROLS.....................................................................................3

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

6. TROUBLE SHOOTING FLOW CHART...................................................................11

7. SPARE PARTS LIST...............................................................................................15

8. EXPLODED DIAGRAM AND SPARE PARTS LIST................................................23

9.

SCHEMATIC DIAGRAMS........................................................................................25

10. PCB LAYOUT DIAGRAM........................................................................................35

4.

ADJUSTING PROCEDURE......................................................................................4

1.

PRECAUTIONS AND NOTICES

Prior to using this manual, please ensure that you have carefully followed all the procedures outlined in
the user manual for this product.

Read all of these instructions.

Save these instructions for later use.

Follow all warnings and instructions marked on the product.

Do not use this product near water.

This display should be installed on a solid horizontal base.

When cleaning, use only a neutral detergent cleaner with a soft damp cloth. Do not spray with liquid or
aerosol cleaners.

Do not expose this display to direct sunlight or heat. Hot air may cause damage to the cabinet and other
parts.

Adequate ventilation must be maintained to ensure reliable and continued operation and to protect the
display from overheating. Do not block ventilation slots and openings with objects or install the display
in a place where ventilation may be hindered.

Do not install this display near a motor or transformer where strong magnetism is generated. Images
on the display will become distorted and the color irregular.

Do not allow metal pieces or objects of any kind fall into the display from ventilation holes.

Slots and openings in the cabinet and the back or bottom are provided for ventilation, to ensure reliable
operation of the product and to protect it from overheating, those openings must not be blocked or
covered. Those openings should never be blocked by placing this product on a bed, sofa, rug, or other
similar surface. This product should never be placed near or over a radiator or heat register. This
product should not be placed in a built-in installation unless proper ventilation is provided.

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2.

SPECIFICATIONS

1.

Specifications

LCD panel type

19.0” TFT(Fujitsu)

Power Consumption

48 W (typ)

Displayable Resolution

SXGA 1280 x 1024 maximum

Pixel dimension

0.294 mm x 0.294 mm

Display Color

16.7 M

Viewing Angle
(CR=10)

Horizontal: ±85

q

Vertical: ±85

q

Response Time

25 ms typ.

Contrast Ratio

500:1 typ.

Brightness

250 cd / m2 typ.

Active Display Area

376 mm horizontal x 301mm vertical

AC/DC adapter

Input:AC 100~264V,47~63 Hz
Output:+12V DC.

Dimensions ( WxHxD )

439 mm(W) x 465mm(H) x 180mm(D)

Weight

7.5 kg (unit)

Input connector

15 Pin D-Sub.

Power management

YES

Temperature

Operating : 0°C ~ +40°C
Storage : -20°C ~ +60°C

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3.

LOCATION OF CONTROLS

3.

LOCATION OF CONTROLS

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The " adjusting procedure" of VG900b model

1. Turn off the display by power button key on the front of bezel,

2. Disconnect the DC power cable from power jack at rear side.

3. Press and hold the “Ÿ” button key on the front of the bezel

4. Connect the power cable with power jack, and keep pressing the “Ÿ” button key.

5. Press the power button key to turn the display on, and then release the “Ÿ” and power button.

6. The unit is set into Reset mode, OSD main window will be shown on the display,
you can see a red message for “ALL RESET” with a red frame inside OSD windows.

7. The LED lights up with orange and change to green color during reset procedure.

8. OSD changes into a message for "Auto Image Adjust", it disappears after reset procedure.

9. The input video signal is shown on display.

4.

ADJUSTING PROCEDURE

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5.

BLOCK DIAGRAM

FROM
A/D ADAPTOR

INTERFACE BOARD(DPWBN5419T8---A)

COMPUTER
GRAPHIC

12V

3.3V
5V

W1

(DB15)

A/D

CONVERTER

AD9883
(U3)

SCALER
SD1210-2
(U8)

DDC
EPROM

24C21A
(U5)

Serial
EEPROM
24C16
(U17)

MPU
(U15)
MTV230P

Serial
EEPROM
24C16
(U9)

JP2
TO

INVERTER

JP3

SWITCH MODE
POWER SUPPLY

19” LCD
PANEL

SW BOARD
DPWBN5418T8----

INVERTER

RUNTP5392T8----

CON1

CON4
5CON

CON2
CON3

JP7

X1
OSC

PLL
U12

AUDIO BOARD
DPWBN5417T8----

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YES

NO

ON

OFF

GREEN

Hsync,Vsync

Or DE error

ORANGE

OSD no response

Picture too dim

The brightness is
different between upper
and lower side of panel

Picture without
Color

Vertical, Horizontal

Out of sync

One or more colored
vertical lines

Even (or odd) vertical
line is dark

Does
picture
display

Back-light
On or off?

A

dark picture

full of
colored
vertical lines

Check
power
LED

Check display
resolution

Check inverter
Check I/F board JP1

Check LCD cable
Check I/F board JP4
Check LCD panel
J1,J2,J3

Check I/F board

Check SW board S1~S4

Check OSD adjustment

Check inverter
Check backlight

Check signal cable
Check I/F board
Check LCD panel

Check LCD panel

Check I/F board

Check SW board
J1
Check inverter
Check I/F board

RGB signal
error

H,V sync
error

or a picture

6. TROUBLE SHOOTING FLOW CHART

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YES

YES

YES

NO

CHECK 5V,3.3VB,
LCD_VCC & 3V3_MCU

START

POWER CKT

(12V,+5V & 3.3V CKT)

POWER CKT

CHECK POWER CKT

END

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YES

YES

NO

NO

OK

YES

SIGNAL

Check U3 O/P

TO SD1210 CKT

ADC CKT

CHECK I/P R,G & B Video,
HSYNC(pin 30),Coast(pin 31) AND
I2C BUS Signal

START

CHECK MCU CKT(I2C
BUS),D_SUB connector
And U2(74LV14)

ADC CKT

REPLACE U3

& VCLK00

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