ViewSonic VA1912W - 19" LCD Monitor User manual

Model No. VS10866
19” Color TFT LCD Display
Service Manual
ViewSonic VA1912W/Wb
ViewSonic
381 Brea Canyon Road, Walnut, California 91789 USA - [phone]
(VA1912W/Wb_SM Rev. 1a Oct. 2005)

I. Copyright
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
Optiquest is a registered trademark of ViewSonic Corporation.
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 SM Editing Date ECR Number Description of Changes Editor
Copyright © 2005 by ViewSonic Corporation. All rights reserved. No part of this publication may be
1a 10/25/05 Initial Release G. Han
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TABLE OF CONTENTS
2. Specification
3. Front Panel Function Control Description
4. Circuit Description
6. Troubleshooting Flow Chart
9. Block Diagram
10. Schematic Diagrams
7. Recommended Spare Parts List
1. Precautions and Safety Notices
5. Adjustment Procedure
8. Exploded Diagram and Exploded Parts List
11. PCB Layout Diagrams
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1. Precautions and Safety Notices
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 surface with sharp or hard objects.
(8) Do not place heavy objects on the LCD display, video cable, or power cord.
(9) Do not use abrasive cleaners, waxes 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. Service 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
is exposed in such areas as the associated 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 the 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 the Signal Interface Connector, be sure not to rotate or tilt the Interface
Connector of the TFT Module.
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(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
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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 INTRODUCTION
FEATURES VA1912w / VA1912wb
Size 19” wide
Luminance (Typ, cd/㎡) 280 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 Yes
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) <1W
Audio Amplifier/Speaker 1.5W/2.5W x2
Tilt ( 20 ° to -5 °) Yes
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)
Weight Package (Gross Kg/lb) 5.7kg (12.5lb)
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
2.2 GENERAL specification
Test Resolution & Frequency 1440 x 900 @ 60Hz
Test Image Size Full Size
Contrast and Brightness Controls Factory Default:
Contrast = 70%, Brightness = 100%
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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
1. Video RGB (Analog)
2. DVI (Digital)
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
2.4 POWER SUPPLY
Power Supply (power build-in) CMO Part Number: 27-D003247
Input Voltage Range 100 TO 240 VAC
Input Frequency Range 50 TO 60 HERTZ
Short Circuit Protection Output can be shorted without damage
Over Current Protection FUSE 3.15 A typical at 250 VAC
Leakage Current 75 mA (Max) at 240VAC / 50Hz
EFFICIENCY 80 % typical at 100VAC @ 60 Hert
Fuse Internal and not user replaceable
Power Dissipation <1 Watts
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 cycle 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
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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
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.
Timing Table
Item Timing Analog Digital
1 640 x 350 @ 70Hz, 31.5kHz Yes Yes
2 640 x 400 @ 60Hz, 31.5kHz Yes* Yes
3 640 x 400 @ 70Hz, 31.5kHz Yes Yes
4 640 x 480 @ 60Hz, 31.5kHz Yes Yes
5 640 x 480 @ 67Hz, 35.0kHz Yes Yes
6 640 x 480 @ 72Hz, 37.9kHz Yes Yes
7 640 x 480 @ 75Hz, 37.5kHz Yes Yes
8 640 x 480 @ 85Hz, 43.27kHz Yes Yes
9 720 x 400 @ 70Hz, 31.5kHz Yes Yes
10 800 x 600 @ 56Hz, 35.1kHz Yes Yes
11 800 x 600 @ 60Hz, 37.9kHz Yes Yes
12 800 x 600 @ 75Hz, 46.9kHz Yes Yes
13 800 x 600 @ 72Hz, 48.1kHz Yes Yes
14 800 x 600 @ 85Hz, 53.7kHz Yes Yes
15 832 x 624 @ 75Hz, 49.7kHz Yes Yes
16 1024 x 768 @ 60Hz, 48.4kHz Yes Yes
17 1024 x 768 @ 70Hz, 56.5kHz Yes Yes
18 1024 x 768 @ 72Hz, 58.1kHz Yes Yes
19 1024 x 768 @ 75Hz, 60.0kHz Yes Yes
20 1024 x 768 @ 85Hz, 68.67kHz Yes Yes
21 1152 x 864@ 75Hz, 67.5kHz Yes Yes
22 1280 x 1024 @ 60Hz, 63.4kHz Yes Yes
23 1280 x 1024 @ 75Hz, 79.97kHz Yes No
24 1280x 768 @ 60Hz, 47.78kHz Yes Yes
25 1280 x 960 @60Hz, 60kHz Yes Yes
26 1440 x 900 @ 60Hz, 55.96kHz Yes Yes
*: The vertical image size might not be full screen.
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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] Input toggle (Analog or Digital)
[▼] 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
Function descriptions
OSD Lock short cuts function for the buttons
The OSD lock will be activated by pressing the front panel control buttons "(1), & (▲)" for 10 seconds. If the user
then tries to access the OSD by pressing any of the buttons "1", "▼", "▲", "2" a message will appear on the screen
for 3 seconds showing "OSD Locked". The OSD lock will be deactivated by pressing the front panel control
buttons "(1), & (▲)" again for 10 seconds.
Note1: When the OSD is locked will lock all functions, including “Volume” and “Mute”
Note 2: Status bar indicating OSD Lock or Unlock is in progress and when complete it will indicate “OSD
Locked”
Note 3: OSD Lock should not lock Power Button and Power Lock function
Power Lock short cuts function for the buttons
The power button lock will be activated by pressing the front panel control buttons "(1), & (▼)" for 10 seconds.
Locking the power button means that the user won't be able to turn off the LCD while the power button is locked.
If the user presses the power button while it is locked, a message will appear on the screen for 3 seconds showing
"Power Button Locked". It also means that with the power button locked, the LCD would automatically turn back
"On" when power is restored after a power failure. If the power button is not in the locked mode, then power
should return to it's previous state when power is restored after a power failure. The power button lock will be
deactivated by pressing the front panel control buttons "(1), & (▼)" again for 10 seconds.
Note 1: Status bar indicating Power Button lock or unlock is in progress and when complete it will indicate
“Power Button Locked”
Note 2: Power should only be lockable in the “On State”
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