ViewSonic Va1912w4 Service Manual

							
 
 
ViewSonic VA1912w-2  VA1912wb-2 
Model No. VS10866 
19” Color TFT LCD  Display 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(VA1912w-2_VA1912wb-2_SM Rev. 1b Aug. 2006) 
ViewSonic 381 Brea Canyon Road, Walnut, California 91789 USA - (800) 888-8583 
Service Manual  
						

							
ViewSonic Corporation
Copyright 
Copyright © 2006 by ViewSonic Corporation.    All rights reserved.    No part of this publication 
may be reproduced, transmitted, tran scribed, 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 ot herwise, 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. 
 
Revision History 
Revision  SM Editing Date  ECR Number  Description of Changes  Editor 
1b  8/09/2006                 VS-E060210         Add VA1912wb-2 from VA1912w-2                        Jamie Chang
       
       
       
       
  
 
1a 04/14/2006 Initial ReleaseJamie Chang 
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Trademarks 
Optiquest is a registered trademar k of ViewSonic Corporation. 
ViewSonic is a registered trademar k of ViewSonic Corporation. 
All other trademarks used within this document ar e the property of their respective owners. 
 
  
						

							
ViewSonic Corporation
TABLE OF CONTENTS 
 
 
1.   Precautions and Safety Notices    1
2.  Specification   3
3.  Front Panel Function Control Description  10
4.  Circuit Description  16
5.  Adjustment Procedure  17
6.  Troubleshooting Flow Chart  37
7.  Recommended Spare Parts List  45
8.  Exploded Diagram and Expl oded Parts List  50
9.  Block Diagram  52
10. Schematic Diagrams  53
11. PCB Layout Diagrams  60
 
 
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1. Precautions and Safety Notices 
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1. Appropriate  Operation   
  (1) Turn off the product before cleaning.   
  (2) Use only a dry soft cloth when cleaning the LCD panel surface.   
  (3) Use a soft cloth soaked with mild detergent to clean the display housing.   
  (4) Use only a high quality, safety approved AC/DC power cord.    (5) Disconnect the power plug from the AC outlet if the product will not be used for a long period of time.   
(6) If smoke, abnormal noise, or strange odor is present, immediately switch the LCD display off.   
(7) Do not touch the LCD panel surf ace with sharp or hard objects.   
(8) Do not place heavy objects on the LCD di splay, video cable, or power cord.   
(9) Do not use abrasive cleaners, waxe s or solvents for your cleaning.   
(10) Do not operate the product under the following conditions:   
  - Extremely hot, cold or humid environment.   
  - Areas containing excessive dust and dirt.   
  - Near any appliance generating a strong magnetic field.   
  - In direct sunlight.   
2. Caution   
  No modification of any circuit should be attempted. Servi ce work should only be performed after you are thoroughly 
familiar with all of the following safety checks and servicing guidelines.   
3. Safety Check   
  Care should be taken while servicing this LCD display. Because of the high voltage used in the inverter circuit, the voltage i s 
exposed in such areas as the a ssociated transformer circuits.   
4. LCD Module Handling Precautions   
4.1 Handling Precautions   
  (1) Since front polarizer is easily damaged, pay attention not to scratch it.   
  (2) Be sure to turn off power supply when connecting or disconnecting input connector.   
  (3) Wipe off water drops immediately. Long contact with water may cause discoloration or spots.   
  (4) When the panel surface is soiled, wipe it  with absorbent cotton or other soft cloth.   
  (5) Since the panel is made of glass, it may break  or crack if dropped or bumped on hard surface.   
  (6) Since CMOS LSI is used in this module, take care of static electricity and ensure human earth when handling.   
  (7) Do not open or modify the Module Assembly.   
  (8) Do not press the reflector sheet at th e back of the module in any direction.   
  (9) In the event that a Module must be put back into the packing container slot after it was taken out of the    container, do  not press the center of the CCFL Reflector  edge. Instead, press at the far ends of the CFL Reflector edge softly. Otherwise 
the TFT Module may be damaged.   
  (10) At the insertion or removal of th e Signal Interface Connector, be sure not to rotate or tilt the In terface Connector of 
the TFT Module.   
  (11) After installation of the TFT Module into an enclosure  (LCD monitor housing, for example), do not twist or bend the 
TFT Module even momentarily. When designing the enclosure, it should be taken into consideration that no 
bending/twisting forces may be applied to the TFT Module from outside. Otherwise the TFT Module may be damaged.   
  (12) The cold cathode fluorescent lamp in the LCD contains a small amount of mercury. Please follow local ordinances or  regulations for disposal.   
  (13) The LCD module contains a small amount of materials having no flammability grade. The LCD module should be 
supplied with power that complies with the requirements of Limited Power Source (IEC60950 or UL1950), or an 
exemption should be applied for.   
  (14) The LCD module is designed so that the CCFL in it is supplied by a Limited Current Circuit (IEC60950 or UL1950). 
Do not connect the CCFL to  a Hazardous Voltage Circuit
 
VA1912w-2_VA1912wb-2  
						

							
ViewSonic Corporation
 
Correct methods :  Incorrect Methods : 
Only touch the metal-frame of the panel or the front cover of the monitor. 
Do not touch the surface of the polarizer .  Surface of the panel is pressed by fingers & this may 
cause “ MURA “ 
  
  Take out the monitor with cushion  Take out the monitor by grasping the LCD panel.  That may cause “ MURA“. 
  
Place the monitor on a clean & soft foam pad .  Place the monitor on foreign objects . 
That could scratch the surface of panel 
  
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2. Specification 
2.1 INSTRUCTION   FEATURES  VA1912w-2 / VA1912wb-2 
Size  19” wide 
Luminance (Typ, cd/㎡)  300 cd/㎡ 
Contrast Ratio (Typ)  500:1 
Colors ( 6 bit + 2 bit FRC)  16.2 M colors 
Response Time (Typ)  8 ms 
Viewing Angle  (H/V) 150 ° / 130 ° 
TFTLCD PANEL 
Recommend resolution  1440 x 900@60Hz 
Analog (75ohms, 0.7/1.0 Vp-p)  Yes Input Signal 
Digital No 
Separate Sync  Yes 
Composite Sync  No Sync Compatibility 
Sync on Green  No 
PC Yes 
Power Mac  Yes Compatibility TV Box (NextVision 6)  Yes 
Power Voltage  AC 100-240V, 50/60Hz  Yes 
On Mode(Max / Typ)  36W(max) / 32W(typ) Power Consumption 
Active Off Mode (Max)  2W 
Audio Amplifier / Speaker  1.5 W / 2.5W x 2 
Tilt ( 20 ° to   -5 °)  Ye s  
Swivel No 
Pivot No Ergonomics 
Height Adjust  No 
OSD Control  [ ; X] [ 1 ] [ ▼] [▲ ] [ 2 ] []   Yes 
Physical    (W x H x D mm)  451
 x 391  x 197  (mm) 
17.8  x 15.4  x 7.8  (in)  
Dimension 
Package (W x H x D mm)    538
 x 470  x 158  (mm) 
21.2  x 18.5  x 6.2  (in) 
Physical (Net kg/lb)  4.5kg (9.9lb) We i g h t  
Package (Gross Kg/lb)  6.2kg (13.7lb) 
Temperature (℉/℃ ) 41 ℉-95 ℉/+5 ℃-+35 ℃ Operating Condition 
Humidity (%)  20 % - 80 % 
Temperature (℉/℃ ) -4 ℉-131 ℉/-20 ℃-55 ℃ Storage Condition 
Humidity (%)  20 % - 85 % 
Regulation CB / TCO99 / UL/cUL / FCC-B / ICES 003 / Argentina-TUV/S / NOM / EPA Energy 
Star / TUV/Ergo / ISO13406-2 / TUV/GS 
/ CE / GOST-R / SASO / BSMI / PSB / 
C-Tick / Korea (MIC) / CCC   
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ViewSonic Corporation
2.2 GENERAL SPECTION   
 
Test Resolution & Frequency 1440 x 900 @ 60Hz 
Test Image Size  Full Size 
Contrast and Brightness Controls  Factory Default:   
Contrast = 70%, Brightness = 100% 
 
2.3 VIDEO INTERFACE 
 
Analog Input Connector  DB-15 (Analog), refer the appendix A
 
Digital Input Connector  N/A 
Default Input Connector  Defaults to the first detected input 
Video Cable Strain Relief  Equal to twice the weight of the monitor for five minutes 
Video Cable Connector DB-15 Pin out  Compliant DDC 2B 
Video Signals 
Video RGB (Analog) 
Separate 
Video Impedance  75 Ohms (Analog) 
Maximum PC Video Signal  950 mV with no damage to monitor 
Maximum Mac Video Signal  1250 mV with no damage to monitor 
Sync Signals  TTL 
DDC 2B  Compliant with Revision 1.3 
Sync Compatibility  Separate Sync 
Video Compatibility Shall be compatible with all PC type computers, 
Macintosh computers, and after market    video cards 
Resolution Compatibility 640 x 350*, 640 x 480, 720 x 400* (640 x 400*), 800 x 
600, 832 x 624, 1024 x 768, 1152 x 864, 1280 x 768, 
1280 x 960, 1280 x 1024, 1440 x 900 
 
* The image vertical size might not be full screen.   
But the image vertical position should be at the center. 
Exclusions  Not compatible with interlaced video 
 
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2.4 POWER SUPPLY Power Supply (Adapter)  Part Number:  27-D003247 
Input Voltage Range  90 to 264 VAC 
Input Frequency Range 47 to 63 Hertz 
Short Circuit Protection OUTPUT CAN BE SHORTED WITHOUT DAMAGE 
Over Current Protection FUSE 3.15
A TY P I CA L AT  250 VA C  
Leakage Current  75 
MA (MAX) AT 240VAC / 50HZ 
Efficiency  80 % TYPICAL AT 100VAC @60HZ 
Fuse  INTERNAL AND NOT USER REPLACEABLE 
Power Dissipation 36 
WAT T S  
Max Input AC Current  1.6
 ARMS  @  nominal RANGE 
Inrush Current (Cold Start)  80 A @ 240VAC , 50HZ 
Power Supply Cold Start  SHALL START AND FUNCTION PROPERLY WHEN 
UNDER FULL LOAD, WITH ALL COMBINATIONS 
OF INPUT VOLTAGE, INPUT FREQUENCY, AND 
OPERATING TEMPERATURE 
Power Supply Transient Immunity 
SHALL  BE ABLE TO WITHSTAND AN  EN61000-4-4 
±2KV TRANSIENT TEST WITH NO DAMAGE 
Power Supply Line Surge Immunity Shall be able to withstand ±2KV (L-L) and ±2.3KV 
(L-PE) with no damage 
Power Supply Missing Cycle Immunity   Shall be able to function properly, without reset or visible 
screen artifacts, when ½ cycl
e of AC power is randomly 
missing at nominal input 
Power Supply Acoustics  The power supply shall not produce audible noise that 
would be detectable by the user.    Audible shall defined 
to be in compliance with ISO 7779 (DIN EN27779:1991) 
Noise measurements of machines acoustics. Power 
Switch noise shall not be considered 
US Type Power Cable   
Separate 3-prong NEMA 5-15P type plug.    Length = 
1.8m. Connects to display. 
Color = Black 
European Type Power Cable Schuko CEE7-7 type plug. 
Length = 1.8m, Connects to display.   
Color = Black 
CCC Type Power Cable   Separate 3-prong type plug.     
Length = 1.8m. Connects to display. 
Color = Black 
PSE Type Power Cable Separate 2-prong NEMA 1-15P type plug.    Length = 
1.8m. Connects to display. 
Color = Black 
Power Saving Operation(Method)  VESA DPMS Signaling 
Power Consumption   
ON Mode < 
36 W (max) /  32 W  (typ) 
ACTIVE OFF <  1 W 
Recovery Time  ON Mode = N/A, ACTIVE OFF < 5 sec 
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2.5 ELECTRICAL REQUIREMENT 
Horizontal / Vertical Frequency Horizontal Frequency  30 – 82 kHz   
Vertical Refresh Rate 50 – 85* Hz. 
Maximum Pixel Clock  135 MHz 
(EDID file is 140MHz) 
Sync Polarity  Independent of sync polarity.  

Primary Presets 
1440 x 900 @ 60Hz 
 
User Presets 
Number of User Presets (recognized timings) Available: 10 presets total in FIFO configuration 
 
Changing Modes 
 
●  Maximum Mode Change Blank Time for image stability : 3 seconds (Max), excluding “Auto Adjust” time       
●  Under DOS mode (640 x 350, 720 x 400 & 640 x 400), there is no “Auto Adjust” feature.  
●  The monitor needs to do “Auto Adjust” the first time a new mode is detected but except the DOS mode 640 x 350, 720 x 
400 & 640 x 400.(see section “0-Touch™ Function Actions”)  
●  While running Change Mode, Auto Adjust or Memory Recall, the image shall blank  
 
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Timing Table
  
Item Timing  Analog  Digital 
1  640 x 350 @ 70Hz, 31.5kHz Yes No 
2  640 x 400 @ 60Hz, 31.5kHz  Yes* No 
3  640 x 400 @ 70Hz, 31.5kHz  Yes No 
4  640 x 480 @ 60Hz, 31.5kHz  Yes No 
5  640 x 480 @ 67Hz, 35.0kHz  Yes No 
6  640 x 480 @ 72Hz, 37.9kHz  Yes No 
7  640 x 480 @ 75Hz, 37.5kHz  Yes No 
8  640 x 480 @ 85Hz, 43.27kHz  Yes No 
9  720 x 400 @ 70Hz, 31.5kHz  Yes No 
10  800 x 600 @ 56Hz, 35.1kHz  Yes No 
11  800 x 600 @ 60Hz, 37.9kHz  Yes No 
12  800 x 600 @ 75Hz, 46.9kHz  Yes No 
13  800 x 600 @ 72Hz, 48.1kHz  Yes No 
14  800 x 600 @ 85Hz, 53.7kHz  Yes No 
15  832 x 624 @ 75Hz, 49.7kHz  Yes No 
16  1024 x 768 @ 60Hz, 48.4kHz  Yes No 
17  1024 x 768 @ 70Hz, 56.5kHz  Yes No 
18  1024 x 768 @ 72Hz, 58.1kHz  Yes No 
19  1024 x 768 @ 75Hz, 60.0kHz  Yes No 
20  1024 x 768 @ 85Hz, 68.67kHz  Yes No 
21  1152 x 864@ 75Hz, 67.5kHz  Yes No 
22  1280 x 1024 @ 60Hz, 63.4kHz  Yes No 
23  1280 x 1024 @ 75Hz, 79.97kHz  Yes No 
24  1280x 768 @ 60Hz, 47.78kHz    Yes No 
25  1280 x 960 @60Hz, 60kHz  Yes No 
26  1440 x 900 @ 60Hz, 55.96kHz  Yes No 
*The image vertical size might not be full screen. 
  
						

							
ViewSonic Corporation
2.6 FRONT PANEL CONTROLS AND INDICATORS 
Front Panel Hardware Controls 
 
Power Switch (Front Head)  Power Control, soft Power Switch. 
Power LED (Front Head)  Green – ON Orange – Active Off 
Dark = Soft Power Switch OFF 
Front Panel Controls (Head) 
[; X] [ 1 ] [ ▼] [▲ ] [ 2 ] [
] 
 
  [
] Power   
[ 1 ] BUTTON 1   
[ 2 ] Button 2 
[ ▲ ] UP ARROW BUTTON 
[ ▼ ] DOWN ARROW BUTTON 
[ ;  X] Audio Mute on/off 
 
Note: Power Button, Button 1 and Button 2 and Mute Button must be 
one-shot logic operation. (i.e. there should be no cycling) 
Reaction Time  OSD must fully appear within 0.5s after pushing Button 1 
 
Short Cuts Function from the button(s) 
[1] Main Menu 
[2]                                Adjust Contrast / Brightness
[▼ ] or [ ▲]  To immediately activate Contrast menu. It should be change to Brightness OSD by 
push button [2] 
[
▼ ] + [ ▲]  Recall both of Contrast and Brightness to default 
[1] + [2]  Toggle 720x400 and 640x400 mode when input 720x400 or 640x400 mode 
[1] + [ ▼] + [ ▲]  White Balance. (Not shown on user’s guide) 
[1] + [ ▼] Power Lock 
[1] + [ ▲] OSD Lock 
[; X]  Audio Mute on /off 
Remark : All the short cuts function are only available while OSD off 
 
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