ViewSonic VX912-4 User manual

ViewSonic VX912-4
Model No. VS10162
19” Color TFT LCD Display
(VX912-4_SM Rev. 1a Jun. 2006)
ViewSonic 381 Brea Canyon Road, Walnut, California 91789 USA - [phone]
Service Manual

ViewSonic Corporation Confidential - Do Not Copy VX912-4
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Copyright
Copyright © 2006 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
Opt quest 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
1a 06/07/2006 Initial Release J. Chang

ViewSonic Corporation Confidential - Do Not Copy VX912-4
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TABLE OF CONTENTS
1.Precautions and Safety Notices 1
2.Specification 4
3.Front Panel Function Control Description 9
4.Circuit Description 11
5.Adjustment Procedure 23
6.Troubleshooting Flow Chart 42
7.Recommended Spare Parts List 45
8.Exploded Diagram and Exploded Parts List 47
9.Block Diagram 50
10.Schematic Diagrams 51
11.PCB Layout Diagrams 58

ViewSonic Corporation Confidential - Do Not Copy VX912-4
1. Precautions and Safety Notices
1. 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 guide line
2. Safety Check :
Care should be taken while servicing this LCD display. Because of the high voltage used in the inverter circuit. These voltage
are exposed in such areas as the associated transformer circuits .
3. POWER SUPPLY REQUIREMENTS
The external power converter for this display utilizes AC and DC cords , AC cord is detachable , but DC cord is
permanently attached .Any attempt to replace another adapter could result in serious problem on the display .
4. LEAKAGE CURRENT HOT CHECK
4-1 Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during this check.
4-2 Connect a 1500 ohm , 10 watt resistor , paralleled by a 0.15uF capacitor between each metallic part and a good earth
ground
4-3 Use an AC voltmeter with 1000 ohm / volt or more sensitivity and measure the AC voltage across the combination
1500 ohm resistor and 0.15uF capacitor.
4-4 Move the resistor connection to each exposed metallic part and measure the voltage.
4-5 Reverse the polarity of the AC plug in the AC outlet and repeat the above measurement.
4-6 Voltage measured must not exceed 1.5 volt RMS, from any exposed metallic part to the ground.A leakage current
tester may be used in the above hot check, in which case any circuit measured must not exceed 1.0 milliamp. In the case of a
measurement exceeding the 1.0 milliamp value, a rework is required to eliminate the chance of a shock hazard .
To Metal Parts
V
AC VOLTMETER
1500 10W
0.15u
.
Earth Ground
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ViewSonic Corporation Confidential - Do Not Copy VX912-4
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“.
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ViewSonic Corporation Confidential - Do Not Copy VX912-4
Correct Methods : Incorrect Methods :
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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ViewSonic Corporation Confidential - Do Not Copy VX912-4
2. Specification
GENERAL specification
Test Resolution & Frequency 1280x1024 @ 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-I (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, Composite, and Sync on Green
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 LVDS
DDC 1/2B Compliant with Revision 1.3
Sync Compatibility Separate Sync, Composite Sync, SOG
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, 1152 x 870,
1280 x 720, 1280 x 960, 1280 x 1024
* 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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ViewSonic Corporation Confidential - Do Not Copy VX912-4
POWER SUPPLY
Internal Power Supply Part Number: FSP035-1PI01
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 3.5 A typical at 12.0 VDC ( Protect when short circuit )
Leakage Current 0.75mA (Max) at 264VAC / 50Hz
Efficiency 77 % typical at 115VAC Full Load
Fuse Internal and not user replaceable
Power Dissipation 35 Watts (typ)
Max Input AC Current 1.2 Arms @ 90VAC, 0.7 Arms @265VAC
Audio interface(SPEAKER SPECIFICATION)
Line input connection 3.5mm stereo jack
Line input signal 1.3Vrms
Line input impendence 10Kohm
Maximum Power output 1W@<5% distortion
Signal to Noise Ratio 72dB
Frequency response 200Hz – 20K
Distortion <5% THD @1K
Vibration There should be no audio vibration with
Volume at 100% and treble/bass at default
Screen image There should be no affect on the screen
Image stability under any conditions.
Connector PC99 requirement Audio in Lime Green pantone # 577C
Cable type / length 3.5mm stereo cable / 1.8m length
Audio DPMS
Speakers stay on where the rest of the monitor is in
power –saving.
Note: There us no guarantee <1w power consumption
in active off mode when the Audio cable is connected.
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ViewSonic Corporation Confidential - Do Not Copy VX912-4
ELECTRICAL REQUIREMENT
Horizontal / Vertical Frequency
Horizontal Frequency 30 – 82 kHz
Vertical Refresh Rate 50 – 75 Hz.
Maximum Pixel Clock 135 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 @ 60Hz, 31.5kHz Yes Yes
3 640 x 400 @ 70Hz, 31.5kHz Yes Yes
4 640 x 480 @ 50Hz, 24.7kHz Yes No
5 640 x 480 @ 60Hz, 31.5kHz Yes Yes
6 640 x 480 @ 67Hz, 35.0kHz Yes Yes
7 640 x 480 @ 72Hz, 37.9kHz Yes Yes
8 640 x 480 @ 75Hz, 37.5kHz Yes Yes
9 640 x 480 @ 85Hz, 43.27kHz Yes Yes
10 720 x 400 @ 70Hz, 31.5kHz 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
15 800 x 600 @ 85Hz, 53.7kHz Yes Yes
16 832 x 624 @ 75Hz, 49.7kHz Yes Yes
17 1024 x 768 @ 60Hz, 48.4kHz Yes Yes
18 1024 x 768 @ 70Hz, 56.5kHz Yes Yes
19 1024 x 768 @ 72Hz, 58.1kHz Yes Yes
20 1024 x 768 @ 75Hz, 60.0kHz Yes Yes
21 1024 x 768 @ 85Hz, 68.67kHz Yes Yes
22 1152 x 864 @ 75Hz, 67.5kHz Yes Yes
23 1152 x 870 @ 75Hz, 68.7kHz Yes Yes
24 1280 x 1024 @ 60Hz, 63.4kHz Yes Yes
25 1280 x 1024 @ 75Hz, 79.97kHz Yes Yes
26 1280x 720 @ 60Hz, 45kHz (HDTV) Yes Yes
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ViewSonic Corporation Confidential - Do Not Copy VX912-4
TFT LCD PANEL
1st Source Panel
Model number HSD HSD190ME13-D10
Type TN type with LVDS interface
Active Size 376.3 (H) x 301.1 (V)
Pixel Arrangement RGB Vertical Stripe
Pixel Pitch 0.294 mm
Glass Treatment Anti Glare (Hard coating 3H)
# of Backlights 4 CCFL edge-light (2 top / 2 bottom)
Backlight Life 40000 Hours (Min)
Luminance (Center) –
Condition:
CT = 6500K, Contrast = Max,
Brightness = Max
300 cd/m2 (Typ after 30 minute warm up)
240 cd/m2 (Min after 30 minute warm up)
Brightness Uniformity 70% (min)
δW = Max Luminance of 9 points/Min Luminance of 9
points
Contrast Ratio 700:1 (typ), 450:1 (min)
Color Depth 16.2 million colors (6 bits + 2 bits FRC)
Viewing Angle (Horizontal) @ CR>10
Typical: 150
Minimum: 130
@ CR>5
Typical: 160
Minimum: N/A
Viewing Angle (Vertical) @ CR>10
Typical: 135
Minimum: 115
@ CR>5
Typical: 150
MINIMUN: N/A
Response Time
10%-90% @ Ta=25°C
5 ms (Tr= 1,5 ms, Tf = 3.5 ms) (typ)
10 ms (Tr= 3 ms, Tf = 7 ms) (max)
Panel Defects Please see Panel Quality Specifications.
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