Viewsonic VA703M-1, VA703M- 2, VA703M- 3, VA703M -4 Service Manual
Service Manual
ViewSonic VA703b-3
VA703m-3
Model No. VS11359
17” Color TFT LCD Display
(VA703b-3_VA703m-3_SM Rev. 1C Dec. 2006)
ViewSonic 381 Brea Canyon Road, Walnut, California 91789 USA - (800) 888-8583
Copyright
Copyright © 2007 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
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
1a 8/23/2006 Initial Release Jamie Chang
1b 10/23/2006 VS-E060300 Add 2nd panel CPT CLAA170EA07Q (8ms) Jamie Chang
1c 12/21/2006 VS-E060414
Phase in INL MT170EN01 V9 (5ms) panel
as backup (updated RSPL / BOM)
Jamie Chang
i
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
TABLE OF CONTENTS
1. Precautions and Safety Notices 1
2. Specification 4
3. Front Panel Function Control Description 10
4. Circuit Description 15
5. Adjustment Procedure 24
6. Troubleshooting Flow Chart 37
7. Recommended Spare Parts List 45
8. Exploded Diagram and Exploded Parts List 49
9. Block Diagram 54
10. Schematic Diagrams 55
11. PCB Layout Diagrams 62
ii
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
1. Precautions and Safety Notices
1. SAFETY PRECAUTIONS
This monitor is manufactured and tested on a ground principle that a user’s safety comes first. However, improper
used or installation may cause damage to the monitor as well as to the user.
WARNINGS:
z This monitor should be operated only at the correct power sources indicated on the label on the rear of the monitor. If
you’re unsure of the power supply in you residence, consult your local dealer or Power Company.
z Use only the special power adapter that comes with this monitor for power input.
z Do not try to repair the monitor by yourself, as it contains no user-serviceable parts. Only the qualified technician can
repair it.
z Do not remove the monitor cabinet. There are high-voltage parts inside that may cause electric shock to human
bodies.
z Stop using the monitor if the cabinet is damaged. Have it checked by a service technician.
z Put your monitor only in a lean, cool, dry environment. If it gets wet, unplug the power cable immediately and consult
your closed dealer.
z Always unplug the monitor before cleaning it. Clean the cabinet with a clean, dry cloth. Apply non-ammonia based
cleaner onto the cloth, not directly onto the glass screen.
z Do not place heavy objects on the monitor or power cord.
2. PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety visual inspections and the protection
afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage,
etc. Before replacing any of these components read the parts list in this manual carefully. The use of substitute
replacement parts, which do not have the same safety characteristics as specified in the parts list, may create shock,
fire, or other hazards.
3. SERVICE NOTES
z When replacing parts or circuit boards, clamp the lead wires around terminals before soldering.
z Keep wires away from high voltage, high temperature components and sharp edges.
z Keep wires in their original position so as to reduce interference.
z Adjustment of this product please refers to the user’ manual.
1
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
4. Handling and Placing Methods
Correct Methods: Incorrect Methods:
Only touch the metal of the LCD panel or the front
cover of he monitor. Do not touch the surface of the
polarizer.
Surface of the LCD panel is pressed by fingers and
that may cause "Mura".
Take out the monitor with cushions.
Taking out the monitor by grasping the LCD panel.
That may cause "Mura".
2
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
Correct Methods: Incorrect Methods:
Place the monitor on a clean and soft foam pad.
Placing the monitor on foreign objects, That could
scratch the surface of the panel or cause "Mura".
The panel is placed facedown on the lap. That may
cause "Mura".
3
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
2. Specification
PRODUCT DEFINITION AND SPECIFICATION
Product Name VA703b-3 / VA703m-3
Model Number VS11359
M model for America
E model for Europe
G model for China
Region
OSD Languages
TFT LCD Panel and Model # INN, Model # :MT170EN01 V7
TFT LCD Panel and Model # CPT Model # :CLAA170EA07Q
TFT LCD Panel and Model # INN, Model # :MT170EN01 V9
Scalar MST TSUM16AL
Input Signal Analog
Sync Compatibility Separate
Audio
Adapter
Power Cable Refer to Appendix D
Analog Cable (1.8 m, color : black), with PC
2001 and Hot Plug Detect &DDC
Audio Cable (1.8m, Color: black) with PC
2001
ViewSonic CD Wizard
ViewSonic Quick Start Guide
Screen Protector Mylar
Hi Pot label
QA pass label
Hg Warnning label
Warranty Sticker For G model only
Warranty Card For G model only
Carton Sticker For G model only
PE bag of Carton
P model for Asia
A model for Australia
S model for Singapore
K model for Korea
U model for UK
English, French, German, Italian, Spanish,
Finnish, Japanese, Traditional Chinese,
Simplified Chinese
1 W @ < 8 % distortion ( for VA703m-3 only)
No
Yes
Yes ( for VA703m-3 only)
Arabic, English, Finnish, Spanish, German,
Italian, Swedish, Polish, Korean, Portuguese,
Russian, French, Simplified Chinese,
Traditional Chinese, Hungary, Czech, Turkish
Yes
Yes
Yes
Yes
For G model only
4
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
1 GENERAL specification
Test Resolution & Frequency 1280 x 1024 @ 60Hz
Test Image Size Full Size
Contrast and Brightness Controls
Factory Default:
Contrast = 70%, Brightness = 100%
2 VIDEO INTERFACE
Analog Input Connector DB-15 (Analog), refer the appendix A
Default Input Connector Defaults to the first detected input
Video Cable Strain Relief
Video Cable Connector DB-15 Pin out Compliant DDC 1/2B
Video Signals 1. 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 LVDS
DDC 1/2B Compliant with Revision 1.3
Sync Compatibility Separate Sync
Video Compatibility
Resolution Compatibility
Exclusions Not compatible with interlaced video
3 POWER SUPPLY
Internal Power Supply
Input Voltage Range
Input Frequency Range
Short Circuit Protection Output can be shorted without damage
Over Current Protection
Leakage Current
Efficiency
Fuse Internal and not user replaceable
Power Dissipation
Max Input AC Current
Inrush Current (Cold Start)
Power Supply Cold Start
Power Supply Transient Immunity
Power Supply Line Surge Immunity
Power Supply Missing Cycle Immunity
Power Supply Acoustics
US Type Power Cable
Power Saving Operation(Method) VESA DPMS Signaling
Power Consumption
Recovery Time On Mode = N/A, Active Off < 3 sec
Equal to twice the weight of the monitor for five
minutes
Shall be compatible with all PC type computers,
Macintosh computers, and after market video cards
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
1024
Part Number: ILPI-020
90 TO 264 VAC
47.5 TO 63 HERTZ
5 A typical at 14 VDC
3.5 mA (Max) at 254VAC / 60Hz
80 % typical at 115VAC Full Load
35 Watts (max)
1.2 Arms @ 100VAC, 0.6 Arms @240VAC
40 A @ 120 VAC, 60 A(max) @ 220 VAC
Shall start and function properly when under full
load, with all combinations of input voltage, input
frequency, and operating temperature
Shall be able to withstand an ANSI/IEEE C62.411980 6000V 200 ampere ring wave transient test
with no damage
Shall be able to withstand 1.5 times nominal line
voltage for one cycle with no damage
Shall be able to function properly, without reset or
visible screen artifacts, when ½ cycle of AC power is
randomly missing at nominal input
The power supply shall not produce audible noise
that would be detectable by the user. Audible shall
define to be in compliance with ISO 7779 (DIN
EN27779:1991) Noise measurements of machines
acoustics. Power Switch noise shall not be
considered
Length = 1.8m. Connects to AC/DC Power Color =
Black
ON Mode < 35 W (max)
POWER SAVING < 2W ,OFF < 1W
4
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
5 ELECTRICAL REQUIREMENT
Horizontal / Vertical Frequency
Horizontal Frequency 30 – 82 KHZ
Vertical Refresh Rate 50 – 85 HZ.
Maximum Pixel Clock
Sync Polarity Independent of sync polarity.
135 MHz
Timing Table
Item Timing Analog
1 640 x 350 @ 70Hz, 31.5kHz
2 640 x 400 @ 70Hz
3 640 x 480 @ 50Hz
4 640 x 480 @ 60Hz, 31.5kHz
5 640 x 480 @ 67Hz, 35.0kHz
6 640 x 480 @ 72Hz, 37.9kHz
7 640 x 480 @ 75Hz, 37.5kHz
8 640 x 480 @ 85Hz, 43.27kHz
9 720 x 400 @ 70Hz, 31.5kHz
10 800 x 600 @ 56Hz, 35.1kHz
11 800 x 600 @ 60Hz, 37.9kHz
12 800 x 600 @ 72Hz, 48.1kHz
13 800 x 600 @ 75Hz, 46.9kHz
14 800 x 600 @ 85Hz, 53.7kHz
15 832 x 624 @ 75Hz, 49.7kHz
16 1024 x 768 @ 60Hz, 48.4kHz
17 1024 x 768 @ 70Hz, 56.5kHz
18 1024 x 768 @ 72Hz, 58.1kHz
19 1024 x 768 @ 75Hz, 60.0kHz
20 1024 x 768 @ 85Hz
21 1152 x 864 @ 75Hz
22 1152 x 870 @ 75Hz
23 1280 x 960 @ 60Hz
24 1280 x 960 @75Hz
25 1280 x 1024 @ 60Hz
26 1280 x 1024 @ 75Hz
*1. Tolerance ≧ ± 2kHz.
*2. Any timing not in the list, it should display as normal or show on “OUT OF RANGE” OSD message without
blanking.
*3. The image quality of 85Hz mode might be worse than 75Hz.
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes*3
Yes
Yes
Yes
Yes
Yes
Yes*3
Yes
Yes
Yes
Yes
Yes
Yes*3
Yes
Yes
Yes
Yes
Yes
Yes
6
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
6 FRONT PANEL CONTROLS AND INDICATORS
Front Panel Hardware Controls
Power Switch (Front Head) Power Control, soft Power Switch.
Green – ON
Power LED (Front Head)
Front Panel Controls (Head)
[ 1 ] [ 2 ] [
Reaction Time
] [▲] [▼]
Short Cuts Function from the button(s)
[1] Main Menu
[2] Auto Image Adjust
[ ] Power Control, soft Power Switch
[▼] 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
[▼] + [▲]+ [ ] Enter Factory Mode
Remark : All the short cuts function are only available while OSD off
Main Menu Controls
Auto Image Adjust
Contrast/Brightness*
1
Audio Adjust ( for VA703m-3 only)
Volume*3, Mute*3
Color Adjust
SRGB, 9300K, 6500K(default), 5400, User Color [R, G, B]
Information [H Frequency, V Frequency, Pixel Clock, Resolution, Model Number,
Serial Number, “www.ViewSonic.com
Manual Image Adjust [H. Size, H./V. Position, Fine Tune, Sharpness*
Setup Menu
Language [English, French, German, Italian, Spanish, Finnish, Simplified Chinese
Traditional Chinese, Japanese],
Resolution Notice, OSD Position*
1
, OSD Timeout, OSD Background
Memory Recall
*1 These functions can be recalled to default by [▼]+ [▲]
2
These functions are not available under Native Resolution Mode
*
3
These functions setting can be recalled to default by [▼]+[▲] under audio mode
*
[Remark] Please refer to the detail in the Appendix C
Orange – Active Off
Dark = Soft Power Switch OFF
[ 1 ] BUTTON 1
[ 2 ] Button 2
] Power
[
[▲] UP ARROW BUTTON
[▼] DOWN ARROW BUTTON
Note: Power Button, Button 1 and Button 2 must be
one-shot logic operation. (i.e. there should be no
cycling)
OSD must fully appear within 0.5s after pushing Button
1
” ]
2
7
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
Factory Defaults
Item Defaults Item Defaults
Contrast 70% Volume
( for VA703m only)
50%
Brightness 100% Balance N/A
Color Temperature 6500K Treble N/A
Sharpness 0% Bass N/A
OSD H. Position 50% 720x400/640x400 720x400
OSD V. Position 50%
OSD Time Out 15 Sec
640x480@60Hz
720x480@60Hz
In SOG and Composite,
720x480@60Hz
640x480@60Hz
N/A
640x480@60Hz
In SOG and Composite,
OSD Background Enabled
1152x864@75Hz
N/A
1152x870@75Hz
In SOG and Composite,
Resolution Notice Enabled
1280x768@60/75/85Hz
1024x768@60/75/85Hz
N/A
AUDIO INTERFACE (SPEAKER SPECIFICATION) ---
( for VA703m only)
Line input connection 3.5 mm stereo jack
Line input signal 1.0Vrms
Line input impedance >10 kOhm
Maximum power output (Electric) 1 W @ < 8% distortion
Signal to Noise Ratio 50 dB
Frequency response 500 Hz – 20 Khz
Distortion
< 8 % THD (@1kHz)
There should be no audible vibration with
Vibration
volume at 100%. (Input signal within 1.0
Vrms)
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
Note: There is no guarantee <1 W power
Audio DPMS
consumption in Active Off mode, when the
Audio Cable is connected
8
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
TFT LCD PANEL
1st Panel Source
Type TN, LVDS
Active Size 337.92 mm (H) x 270.336mm (V)
Pixel Arrangement RGB Vertical Stripe
Pixel Pitch 0.264 mm
Glass Treatment Anti Glare (Hard coating 3H)
# of Backlights 4 CCFL edge-light
Backlight Life 50,000 Hours (Min)
Luminance –Condition: CT = 6500 K
Contrast = Max, Brightness = Max
Brightness Uniformity 80%(typ) / 75 % (min)
Contrast Ratio 600 :1 (Typ), 500 :1 (Min)
Color Depth Vertical) 16.2 million colors (6+2 bit panel)
Viewing Angle (Horizontal) 150 deg (Typ)@ CR>10 / 170 deg (Typ)@ CR>5
Viewing Angle (Vertical) 135 deg (Typ) @ CR>10 / 155 deg (Typ)@ CR>5
Response Time
10%-90% @ Ta=25°C
Panel Defects Please see Panel Quality Specifications.
INN MT170EN01 V7
280 cd/m2 (Typ after 30 minute warm up)
250 cd/m2 (Min after 30 minute warm up)
8 ms (Tr= 2 ms, Tf = 6 ms) (Typ)
16 ms (Tr= 4 ms, Tf = 12 ms) (max)
2nd Panel Source
Type TN, LVDS
Active Size 337.92 mm (H) x 270.336mm (V)
Pixel Arrangement RGB Vertical Stripe
Pixel Pitch 0.264 mm
Glass Treatment Anti Glare (Hard coating 3H)
# of Backlights 4 CCFL edge-light
Backlight Life 40,000 Hours (Min) @7mA
Luminance –Condition: CT = 6500 K
Contrast = Max, Brightness = Max
Brightness Uniformity 72%(typ) / 70 % (min)
Contrast Ratio 500 :1 (Typ), 400 :1 (Min)
Color Depth Vertical) 16.2 million colors (6+2 bit panel)
Viewing Angle (Horizontal) 140 deg (Typ)@ CR>10 / 170 deg (Typ)@ CR>5
Viewing Angle (Vertical) 130 deg (Typ) @ CR>10 / 170 deg (Typ)@ CR>5
Response Time
10%-90% @ Ta=25°C
Panel Defects Please see Panel Quality Specifications.
CPT CLAA170EA07Q
290 cd/m2 (Typ after 30 minute warm up)
250 cd/m2 (Min after 30 minute warm up)
8 ms (Tr= 3 ms, Tf = 5 ms) (Typ)
16 ms (Tr= 6 ms, Tf = 10 ms) (max)
3rd Panel Source
Type TN, LVDS
Active Size 337.92 mm (H) x 270mm (V)
Pixel Arrangement RGB Vertical Stripe
Pixel Pitch 0.264 mm
Glass Treatment Anti Glare (Hard coating 3H)
# of Backlights 4 CCFL edge-light
Backlight Life 50,000 Hours (Min)
Luminance –Condition: CT = 6500 K
Contrast = Max, Brightness = Max
Brightness Uniformity 80%(typ) / 75 % (min)
Contrast Ratio 800 :1 (Typ), 600 :1 (Min)
Color Depth Vertical) 16.7 million colors (6+2 bit panel)
Viewing Angle (Horizontal) 160 deg (Typ)@ CR>10 / 170 deg (Typ)@ CR>5
Viewing Angle (Vertical) 160 deg (Typ) @ CR>10 / 170 deg (Typ)@ CR>5
Response Time
10%-90% @ Ta=25°C
Panel Defects Please see Panel Quality Specifications.
INN MT170EN01 V9
300 cd/m2 (Typ after 30 minute warm up)
250 cd/m2 (Min after 30 minute warm up)
5 ms (Typ) / 10 ms (max)
9
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
3. Front Panel Function Control Description
Adjusting the Screen Image
Use the buttons on the front control panel to display and adjust the OSD controls which display
on the screen. The OSD controls are explained at the top of the next page and are defined in
“Main Menu Controls” on page 10.
Main Menu
with OSD controls
Front Control Panel
shown below in detail
Displays the control screen
for the highlighted control.
Also toggles between two
controls on some screens.
Also a shortcut to Auto
Image Adjust.
Displays the
Main Menu or
exits the
control screen
and saves
adjustments.
Power light
Green = ON
Orange = Power Saving
St andby Power
On/Off
Scrolls through
menu options and
adjusts the
displayed control.
Also a shortcut to
display the
Contrast
adjustment control
screen.
10
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
Do the following to adjust the display setting:
1. To display the Main Menu, press button [1].
NOTE: All OSD menus and adjustment screens disappear automatically after about 15
seconds. This is adjustable through the OSD timeout setting in the setup menu.
2. To select a control to adjust, pressSorTto scroll up or down in the Main Menu.
3. After the desired control is selected, press button [2]. A control screen like the one shown
below appears.
The line at the bottom of the screen shows
the current functions of buttons 1 and 2:
Exit or select the Brightness control.
4. To adjust the control, press the up S or down T buttons.
5. To save the adjustments and exit the menu, press button [1] twice.
The following tips may help you optimize your display:
• Adjust the computer's graphics card so that it outputs a 1280 x 1024 @ 60Hz video signal to
the LCD display . (Look for instructions on “changing the refresh rate” in the graphics card' s
user guide.)
• If necessary, make small adjustments using H. POSITION and V. POSITION until the
screen image is completely visible. (The black border around the edge of the screen should
barely touch the illuminated “active area” of the LCD display.)
11
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
Main Menu Controls
Adjust the menu items shown below by using the up S and down T buttons.
Control Explanation
Auto Image Adjust automatically sizes, centers, and fine tunes the video signal
to eliminate waviness and distortion. Press the [2] button to obtain a sharper
image.
NOTE: Auto Image Adjust works with most common video cards. If this
function does not work on your LCD display, then lower the video refresh rate
to 60 Hz and set the resolution to its pre-set value.
Contrast adjusts the difference between the image background (black level)
and the foreground (white level).
Brightness adjusts background black level of the screen image.
Audio Adjust
Volume increases the volume, decreases the volume, and mutes the audio.
Mute temporarily silences audio output.
Color Adjust provides several color adjustment modes, including preset color
temperatures and a User Color mode which allows independent adjustment of
red (R), green (G), and blue (B). The factory setting for this product is 6500K
(6500 Kelvin).
sRGB-This is quickly becoming the industry standard for color management,
with support being included in many of the latest applications. Enabling this
setting allows the LCD display to more accurately display colors the way they
were originally intended. Enabling the sRGB setting will cause the Contrast and
Brightness adjustments to be disabled.
9300K-Adds blue to the screen image for cooler white (used in most office
settings with fluorescent lighting).
6500K-Adds red to the screen image for warmer white and richer red.
5400K-Adds green to the screen image for a darker color.
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
12
Control Explanation
User Color Individual adjustments for red (R), green (G), and blue (B).
1. To select color (R, G or B) press button [2].
2. To adjust selected color, pressSandT.
Important: If you select RECALL from the Main Menu when the product is
set to a Preset Timing Mode, colors return to the 6500K factory preset.
Information displays the timing mode (video signal input) coming from the
graphics card in the computer, the LCD model number, the serial number, and
the ViewSonic® website URL. See your graphics card’s user guide for
instructions on changing the resolution and refresh rate (vertical frequency).
NOTE: VESA 1280 x 1024 @ 60Hz (recommended) means that the resolution
is 1280 x 1024 and the refresh rate is 60 Hertz.
Manual Image Adjust displays the Manual Image Adjust menu.
H. Size (Horizontal Size) adjusts the width of the screen image.
H./V. Position (Horizontal/Vertical Position) moves the screen image left or
right and up or down.
13
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
Control Explanation
Fine Tune sharpens the focus by aligning text and/or graphics with pixel
boundaries.
NOTE: Try Auto Image Adjust first.
Sharpness adjusts the clarity and focus of the screen image.
Setup Menu displays the menu shown below:
Language Select allows the user to choose the language used in the menus and
control screens.
Resolution Notice displays the Resolution Notice menu shown below.
Resolution Notice advises the optimal resolution to use.
OSD Position allows the user to move the OSD menus and control screens.
OSD Timeout sets the length of time the OSD screen is displayed. For example,
with a “15 second” setting, if a control is not pushed within 15 seconds, the
display screen disappears.
OSD Background allows the user to turn the OSD background On or Off.
Memory Recall returns the adjustments back to factory settings if the display is
operating in a factory Preset Timing Mode listed in the Specifications of this
manual.
Exception: This control does not affect changes made with the User Color
control, Language Select or Power Lock setting.
14
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
4. Circuit Description
2.1 Switching Mode Power Supply
2.1.1 AC Current Input Circuit
P801 is a connector for connecting AC Power. F801 is a fuse to protect all the circuit. AC input voltage is from
90V to 264V. R820 and R821 joined between two inputting main circuit to prevent man from shock. L801 is used to
clear up low frequency wave. C801 and C806 are used to discharge the waves that L801 produced. High
frequency waves are damped by C801 and C806. D801 is a rectifier which composed of 4 build-in diodes, it inverts
AC to DC.
2.1.2 High Voltage to Low Voltage Control Circuit
C805 is used to smooth the wave from rectifier. IC802 is a highly integrated PWM controller, which build-in a
power MOSFET. When rectified DC high voltage is applied to the DRAIN pin during start-up, the MOSFET is off
initially, and the CONTROL pin capacitor is charged through a switched high voltage current source connected
internally between the DRAIN and CONTROL pins. When the CONTROL pin voltage Vc reaches approximately
5.8V, the control circuitry is activated and the soft-start begins. The soft-start circuit gradually increases the duty
cycle of the MOSFET from zero to the maximum value over approximately 10ms. If no external feedback/supply
current is fed into the CONTROL pin by the end of the soft-start, the high voltage current source is turned off and
the CONTROL pin will start discharging in response to the supply current drawn by the control circuitry.
Resistor R803, R807, R824 and R825 are for line over voltage shut-down (OVP) and line under-voltage
detection (UVP).Resistors R801, R805, R822, and R823 are for external current limit adjustment, and used to
reduce the current limit externally to a value close to the operating peak current of primary about 1.35A. The mean
is power will protected when the primary current over about 1.35A.
When PWM is turned off, the main current flow will be consumed through D804 and ZD802, This will prevent
MOSFET which built-in IC802 from being damaged under large current impulse and voltage spike.
D806 and C815 provide internal Auxiliary current to CONTROL pin during normal operation. In addition, error
amplifier and feedback current to the CONTROL pin are for duty cycle control.
2.1.3 DC_5V and DC_14V Output Circuit
For DC 5V, D805 is used to rectify the inducted current. R806 and C811 are used to store energy when current
is reversed. The parts including C812, C814, C822, C821, B801 and L803 are used to smooth the current waves.
For DC 14V, D803 is used to rectify the inducted current. R802 and C802 are used to store energy when
current is reversed. The parts including C808, C810 and L802 are used to smooth the current waves.
2.1.4 Feedback and OVP Protect Circuit
Pin R of IC803 is supplied 2.5V stable voltage. It is connected to 5V and 14V output through R811,
R810 and R818. R811, R810 and R818 are output sampling resistor. When the sampling voltage more
than 2.5V or less than 2.5V, feedback current of IC802 will change, this can change the voltage from
transformer T801.
Q802, R827, R828 and ZD801 make up of dummy loading circuit. For start-up sequence, during 5V
output take place high loading first, this dummy loading circuit operated to insure 14V not be increased.
2. 2 Inverter Circuit
2.2.1 Low voltage to high voltage circuit
14VDC provides the power for IC501; the control signals Brightness and ON/OFF come from I/F board.
ON/OFF signal connect to pin10 of IC501 and makes IC501 enable. Brightness signal connect to pin4 of IC501
and regulates the panel brightness, R526, R529, C505 make up a network of delaying time circuit and R523, R524
make up a divided voltage network, C504 is used to dump noise. The operation frequency is determined by the
external Resistor R522 and capacitor C529 connected to pin13 of IC501. BURST MODE regulated dimming
frequency is determined by the external resistor R527 and capacitor C506 connected to pin11 of IC501. C508 is
used for soft start and compensation, C507, C505 are used for dump noise.
The output drives, include DRV1, DRV2 (pins1,15 respectively) output square pulses to drive MOSFET U501,
U502, and each of U501, U502 , is consist of a N channel MOSFET. U501,OR U502 work as Push-Pull- topology, it
is high efficient, PWM switching.
During start up, VSEN (pin6) senses the voltage at the transformer secondary. When VSEN reaches 3.0V, the
output voltage is regulated. If no current is sensed approximately 2seconds IC501 shut off.
15
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
The current flowing through CCFL is sensed and regulated through sense resistor R509, R534. The feedback
voltage connected to Pin5 (ISEN), then compared with a reference voltage (1.5V) via a current amplifier, resulting in
PWM drive outputs to PUSH-PULL switches.
2.2.2 Protection circuit
Over Voltage Protection and over-current protection are monitored by the voltage on VSEN(Pin 6) During
normal operation , if a CCFL is damaged or removed ,the voltage at VSEN (Pin6) increases .Once the voltage at
VSEN exceeds 2.0V (OVPT Setting) the driver output duty cycle is regulated and the shutdown delay timer is
activated.OVPT set the overall protection threshold voltage that is lower than 3V (VSEN threshold). Once the
voltage at TIMER pin reached about 3v ,the IC will shut down and latch .R501, R503,C525,C527 are connected in
high voltage output connector, the divided AC voltage is inverted DC voltage through D503,
D504,D507,D508 ,R530 and C516are used to rectify wave & dump noise. Then the voltage signal reaches Pin6
VSEN of IC501, when the voltage changes, build-in PWM of IC501 will adjust output voltage.
Open Lamp Protection: In normal operation, R509 are sensed a high level DC voltage,If a CCFL is removed
or damaged during normal ,the voltage at SSTCMP(Pin12) rises rapidly .when the voltage at SSTCMP reaches a
threshold of approximately 2.5V,a current source charges the capacitor(C511)connected to TIMER(Pin3).Once the
voltage level at the TIMER pin reaches a threshold of approximately 3v,The drive outputs shut down and latch.
2.3 I/F Board Circuit
2.3.1 Power Input
+5V is from the power board and supply for U101(LD1117AL-3.3V)﹑U102(LD1117AL-1.8V)﹑U105(TSUM16AL)
and panel. +3.3V output is generated from +5V through C102 and C104 filtering, and U101 outputs. +3.3V is used
for U105 (MCU & Scaler: TSUM16AL). +1.8V output is generated from +3.3V through C166, C105 and C106
filtering, and U102 outputs. +1.8V is only used for U105.
2.3.2 MCU & Scaler(TSUM16AL)
The frequency of XTAL1 is 14.318MHz. U105 # 48 is defined as panel-enable. When the I/O port is high, Q101 and
Q103 are conducted. And then after C108 and C109 filtering, obtain the voltage of VLCD, which will be connected
to CN104. U105 # 85 is defined as CCFL-enable. When the I/O port is low, Q106 is pulled up and the backlights
are on; When the I/O port is high, Q106 is conducted and the backlights are off. U105 # 35 is defined as DET-VGA,
connected with CN103 #5. U105 # 84 is a pin of hardwire reset. U105 # 54-# 55,# 58-# 65, # 67-# 74, # 77-# 78
output LVDS digital data of 8 bit to panel control circuit through CN104. U105 # 86 generates a PWM waveform by
regulating the duty to control the brightness of the backlights.
U103 is EEPROM used for saving EDID data, which is connected by SCL and SDA pins with # 31 and # 30 of
TSUM16AL.
U104 is a flash memory, U104 # 2, # 1, # 6, # 5 are the communications with U105 # 37-# 40.
U108 is EEPROM used for saving user’s OSD setting. U108 is connected by SCL and SDA pin with # 44 and # 43
of TSUM16AL.
2.3.3 VGA Input
Signal R, G, B input through CN103 #1, #2, #3, and C112, C113 and C114 filtering the high frequency noise. Signal
HSYNC and VSYNC input through CN103 #13 and #14, and C125, R137, C126, R136 filtering. Then the analog
signal enters U105, and then U104 deals with it internally. In addition, TVS101, TVS102, TVS103, TVS104 (the
four are BAV99), ZD101, ZD105, ZD106, ZD107, ZD108(they are constant voltage diode of 5V6) are ESD
protector. Signal DDC-SCL inputs via CN103 #15, and then passes through ZD101 for ESD protection, goes into
EDID EEPROM IC U103. Signal DDC-SDA inputs via CN103 #12, and then passes through ZD107 for ESD
protection, goes into EDID EEPROM IC U103. CN103 #5 is defined as cable detect pin, this detector realizes via
R124 and U105 # 35,The PC-5V of U103 is supplied by PC via CN103 #9 with D103 for ESD protection, or
supplied by Monitor self via D103.U103 is an EEPROM IC, which is a kind of memory and used for saving EDID
data.
2.3.4 Button Control
Button “Key-Power” is defined as power on/off, which is connected to U105 # 90 through CN105 # 6.
Button “Key-2” is defined as two functions of selecting and adjustment, which is connected to U105 #94 through
CN105 # 5.
Button “Key-Up” is defined as plus, which is connected to U105 # 95 through CN105 # 8.
Button “Key-Down” is defined as minus, which is connected to U105 # 99 through CN105 # 7.
Button “Key-1” is defined as two functions of menu and exit, which is connected to U105 # 89 through CN105 # 4.
LED indicator on the front bezel is defined as follows:
a. When press button “Key-Power”, U105 # 91 is pulled down and U105 # 92 is pulled high, so Q102 is conducted
and the LED indicator is green.
b. When in power-saving mode, U105 # 91 is pulled high and U105 # 92 is pulled down, so Q105 is conducted and
the LED indicator is orange.
16
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
3. FACTORY PRESET TIMING TABLE
TIMING
FH(KHz)
FV(Hz)
Sync
Polarity
Total
(Dot/Line)
Active
(Dot/Line)
Sync Width
(Dot/Line)
Back Porch
(Dot/Line)
Pixel
Freq.(MHz)
640*350@70Hz
IBM
640*400@70Hz
IBM
720*400@70Hz
640*480@50Hz
VESA
640*480@60Hz
640*480@67Hz
VESA
640*480@72Hz
VESA
640*480@75Hz
VESA
640*480@85Hz
VESA
800*600@56Hz
VESA
800*600@60Hz
VESA
800*600@72Hz
VESA
800*600@75Hz
VESA
800*600@85Hz
MAC
832*624@75Hz
VESA
1024*768@60Hz
VESA
1024*768@70Hz
1024*768@75Hz
1024*768@85Hz
1024*768@72Hz
VESA
1152*864@75Hz
MAC
31.469 + 800 640 96 48
70.086 − 449 350 2 60
31.469 − 800 640 96 48
70.086 + 449 400 2 35
31.469 −
70.087 +
24.700 −
50.000 −
31.469 −
59.940 −
35.000 −
66.667 −
37.861 −
72.809 −
37.500 −
75.000 −
43.269 −
85.008 −
35.156 +
56.250 +
37.879 +
60.317 +
48.077 +
72.188 +
46.875 +
75.000 +
53.674 + 1048 800 64 152
85.061 + 631 600 3 27
49.725 −
74.550 −
48.363
60.004
56.476
70.069
60.023 + 1312 1024 96 176 VESA
75.029 + 800 768 3 28
68.677 + 1376 1024 96 208 VESA
84.997 + 808 768 3 36
57.700 − 1360 1024 136 144
72.125 − 800 768 6 26
67.500
75.000
68.681
−
−
−
−
+
+
−
900 720 108 54
449 400 2 35
800 640 96 48
494 480 2 8
800 640 96 40
525 480 2 25
864 640 64 96
525 480 3 39
832 640 40 120
520 480 3 20
840 640 64 120
500 480 3 16
832 640 56 80
509 480 3 25
1024 800 72 128
625 600 2 22
1056 800 128 88
628 600 4 23
1040 800 120 64
666 600 6 23
1056 800 80 160
625 600 3 21
1152 832 64 224
667 632 3 39
1344 1024
806 768
1328 1024 136 144
806 768 6 29
1600 1152 128 256
900 864 3 32
1456 1152 128 144
136 160
6 29
75.000
78.750
94.500
78.472
108.000
100.000
25.175
25.175
28.322
19.760
25.175
30.240
31.500
31.500
36.000
36.000
40.000
50.000
49.500
56.250
57.283
65.000
17
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
1152*870@75Hz
1280*960@60Hz
1280*960@75Hz
1280*1024@60Hz
VESA
1280*1024@75Hz
75.062
60.000 + 1800 1280 112 312 VESA
60.000 + 1000 960 3 36
75.000 + 1800 1280 112 312
75.000 + 1000 960 3 36
63.981 + 1688 1280 112 248 VESA
60.020 + 1066 1024 3 38
79.976
75.025
−
+
+
915 870 3 39
1688 1280 144 248
1066 1024 3 38
108.000
130.000
108.000
135.000
4. Power On/Off Sequence
4.1 Hardware Power ON
When power cord is plugged into AC socket, SMPS starts work and provides U105 with VCC5V. When VCC5V
inputs, U105 resets circuit active, sets U105 all registers to preset modes, and then monitor goes into stand-by
mode. That means hardware power on has been completed.
4.2 Software Power ON/OFF
When press power key, U105 # 90 recieves low pulse,and then U105 will do the power on/off.
- If Power ON, U105 # 91(LED_Green) will send out Low potential, and then LED green on.
- If Power OFF, U105 # 91(LED_Green) will send out High potential, and then LED Off.
The Panel_Vcc, Backlight_En, CLK/DATA output to panel will follow the following sequency.
T1 (ms) T2 (ms) T3 (ms) T4 (ms) T5 (ms) T6 (ms) T7 (ms)
0.1~10 0~10 >200 >100 0~50 0.1~15 >1000
5. AC Outlet Pin Assignment
3
1 2
Pin Symbol Description
1 L Live
2 N Neutral
P801
3 E GND
18
ViewSonic Corporation Confidential - Do Not Copy VA703b-3_VA703m-3
Loading...