ViewSonic VA2012W User manual

Model No. VS10859
20” Color TFT LCD Display
Service Manual
ViewSonic
381 Brea Canyon Road, Walnut, California 91789 USA - [phone]
VA2012wb
ViewSonic VA2012w
(VA2012w_VA2012wb_SM Rev. 1a Nov. 2005)

Copyright
Copyright
¤
2005by ViewSonic Corporation. All rights reserved. No partof 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.
Optiquest is a registered trademark of ViewSonic Corporation.
Revision History
ECR Number Description of Changes
EditorRevision SM Editing Date
Initial Release
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1a 11/29/05 BonnieT.

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
1
5
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14
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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 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. LCDModule 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 CMOSLSI isusedinthis 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.
1. Precautions and Safety Notices
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(11) After installation of theTFT Module intoan enclosure(LCDmonitor 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 theTFT 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 fordisposal.
(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 theCCFL to a HazardousVoltage Circuit.
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VA2012w series handling Notice
Correct Method Incorrect method
Correct Method Incorrect method
Correct Method Incorrect method
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Correct Method Incorrect method
Correct Method Incorrect method
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2. Specificationtion
GENERAL specification
Test Resolution & Frequency “1680 X 1050” @ 60Hz
Test Image Size Full Size
Contrast and Brightness Controls Factory Default:
Contrast = 70%, Brightness = 100%
VIDEO INTERFACE
Analog Input Connector DB-15 (Analog), refer the appendix A
Digital Input Connector DVI-D (Digital), refer the appendix B
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 1/2B
Video Signals
1. Video RGB (Analog)
Separate
2. TMDS (Digital)
Video Impedance 75 Ohms (Analog), 100 Ohms (Digital)
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 1/2B 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,
1280 x 720, 1280 x 1024, 1600 x 1200,
1680 x 1050
Exclusions Not compatible with interlaced video
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POWER SUPPLY
Internal Power Supply Part Number: EADP-64CF
Input Voltage Range 90 TO 264 VAC
Input Frequency Range 47.5 TO 63 HERTZ
Short Circuit Protection Output can be shorted without damage
Over Current Protection Output current <10A
Leakage Current 3.5mA (Max) at 254VAC / 60Hz
EFFICIENCY 80 % typical at 115VAC Full Load
Fuse Internal and not user replaceable
Power Dissipation 64 Watts (typ)
Max Input AC Current 1.5 Arms @ 90VAC
INRUSH CURRENT (COLD START) 80 A(max) @230VAC
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 ANSI/IEEE
C62.41-1980 6000V 200 ampere ring wave
transient test with no damage
Power Supply Line Surge Immunity Shall be able to withstand 1.5 times nominal
line voltage for one cycle 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
US Type Power Cable
Separate 3-prong NEMA 5-15P type plug.
Length = 1.8m. Connects to AC/DC Power
Adapter. Color = Black
European Type Power Cable Schuko CEE7-7. Length = 1.8m, Connects
to AC outlet. Color = Black
Power Saving Operation(Method) VESA DPMS Signaling
Power Consumption ON Mode < 50 W (max) / 47 W (typ)
ACTIVE OFF < 2W
Recovery Time ON MODE = N/A, ACTIVE OFF < 3 SEC
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ELECTRICAL REQUIREMENT
Horizontal / Vertical Frequency
Horizontal Frequency ANALOG: 30 – 94 KHZ
DIGITAL : 30-82 KHZ
Vertical Refresh Rate 50 – 75 HZ.
Maximum Pixel Clock Analog: 205 Mhz
Digital: 165 MHz
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 @ 70Hz, 31.5kHz Yes Yes
3. 640 x 480 @ 60Hz, 31.5kHz Yes Yes
4. 640 x 480 @ 67Hz, 35.0kHz Yes Yes
5. 640 x 480 @ 72Hz, 37.9kHz Yes Yes
6. 640 x 480 @ 75Hz, 37.5kHz Yes Yes
7. 720 x 400 @ 70Hz, 31.5kHz Yes Yes
8. 720 x 480i 59.94/60Hz @ 15.7 kHz Yes Yes
9. 720 x 576p 50Hz @ 31.25kHz Yes Yes
10. 720 x 576i 50Hz @ 15.62kHz Yes Yes
11. 800 x 600 @ 56Hz, 35.1kHz Yes Yes
12. 800 x 600 @ 60Hz, 37.9kHz Yes Yes
13. 800 x 600 @ 75Hz, 46.9kHz Yes Yes
14. 800 x 600 @ 72Hz, 48.1kHz 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. 1280x720p 50Hz @ 37.5kHz Yes Yes
21. 1280x 720 @ 60Hz, 45kHz Yes Yes
22. 1280 x 1024 @ 60Hz, 63.4kHz Yes Yes
23. 1280 x 1024 @ 75Hz, 79.97kHz Yes Yes
24. 1600 x 1200 @ 60Hz, 75kHz Yes Yes
25. 1600 x 1200 @ 70Hz, 87.5kkHz Yes No
26. 1600 x 1200 @ 75Hz, 93.8kHz Yes No
27. 1680 x 1050 @ 60Hz, 65.3 kHz Yes Yes
28. 1680 x 1050 @ 75Hz, 82.3 kHz Yes No
29. 1920 x 1080i @ 50Hz, 56.5kHz Yes Yes
30. 1920 x 1080p @ 50Hz, 62.5kHz Yes Yes
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