ViewSonic VX750 VLCDS27089-1W User manual

Model No. VLCDS27089-1W
17” Color TFT LCD Display
Service Manual
ViewSonic VX7501
ViewSonic
381 Brea Canyon Road, Walnut, California 91789 USA - [phone]
(VX750_SM_755 Rev. 1a Apr. 2004)

Copyright
Copyright
¤
2004by 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
Revision Date Description Of Changes Approval
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1a 04/27/04 Initial Release DCN-3772 Angela Lu

TABLE OF CONTENTS
2. Specification
3. Front Panel Function Control Description
4. Circuit Description
6. Trouble Shooting Flow Chart
9. Block Diagram
10. Schematic Diagrams
7. Recommended Spare Parts List
1. Precautions and Safety Notices
5. Adjusting Procedure
8. Exploded Diagram And Spare Parts List
11. PCB Layout Diagrams
1
2
3
9
21
38
46
51
53
56
64
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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 betaken while servicing this LCDdisplay,due to thehigh voltageused in the inverter circuit.
High voltage is exposed in suchareas as the associated transformer circuits .
3. POWER SUPPLY REQUIREMENTS
The external power converter for this display utilizes AC and DC cords. The AC cord is detachable ,butthe
DC cord is permanently attached .Any attempt to replace another adapter could result in damage to 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 a1500ohm , 10wattresistor , paralleledwith a0.15uF capacitorbetween each metallicpart
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
1. Precautions and Safety Notices
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x H x D ) mm
502 x 405 x 195 mm
d:
mm
mm
mm
ering )
Tf / typical)
te : /m²
/ 9300°K
Hz
Mechanical :
Dimension ( W
Set a. with stand:
b. Without stan 502 x 340 x 63 mm
Base (L X W): 275 x 195 mm
Packing:(Wx H x D ) mm:572 x 491 x240
Weight :Net /Gross ( Kg): 5.6 /8.2
Wall Mount (VESA): 100 x 100
LCD Panel type: QDI / QD17EL07
Max. resolution (HxV) : 1280 x 1024
Nominal picture size (HxV): 338 mm x 270
Display colors: 16.2 M ( 6 bit + dith
Dot pitch: 0.264 mm
Response time: 4 +12 / 16ms (Tr +
Brightness (100% whi ) Typical : 270 cd/m² , Min. 220cd
Contrast : Typical : 450:1, Min. 300:1
Viewing angle : 75 / 75 /65 / 60 (L/R/T/B CR>=10)
Synchronization: Fh = 31~82 KHz / Fv=50~85Hz
Presets: 18timingmodes
OSD Language : 9 languages
Color Temperature : sRGB , 6500°K (default)
5400°K/UserR,G,B
Plug & Play : DDC1/2B interface
Scaler chip: Mstar MST 8131
Audio Input Connector: 3.5 mm Stereo, PC2001
Audio Amplifier : 5W x 2 (chip :TPA3002)
AC Power range: 90 V ~ 264 V, 50 Hz / 60
Power consumption: < 50W green / < 1W amber
(On/Offmode)
2. Specification
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Adjusting the Screen Image
Use the buttons on the front control panel to display and adjust the OnView®
controls which display on the screen. The OnView controls are explained at the
top of the next page.
Main Menu
With OnView controls
UP / DOWN : Scrolls through menu options and adjusts the displayed control.
Also a shortcut to display the Contrast adjustment control screen.
2 Enter : Displays the control screen for the highlighted control.
INPUT SELECT : Also toggles between two controls on some screens.
Also a shortcut to Auto Image Adjust.
1 MENU : Displays the Main Menu or exits the control screen and saves adjustments.
VOL- / VOL+ : Decreases or increases volume.
Power On / Off
Power light
Blue = ON
Orange = Power Saving
3. Front Panel Function Control Description
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. (The black border around the
edge of the screen should barely touch the illuminated “active area” of the
LCD dislay.)
The line at the
bottom of the
screen tells you
what you can do
next: Exit or Select
the control that is
highlighted.
Do the following to adjust the screen image:
1To display the Main Menu, press button [1].
4To adjust the control, press the up Ior down Jbuttons.
5To save the adjustments and exit the menu, press button [1] twice.
The following tips may help you optimize your display:
• Adjust your computer's graphic card so that it outputs a video signal 1280 x
1024 @ 60 Hz to the LCD dislay. (Look for instructions on “changing the
refresh rate” in your graphic card's user guide.)
• If necessary, make small adjustments using H. POSITION and V. POSITION
until the screen image is completely visible
NOTE: All OnView menus and adjustment screens disappear automatically
after about 15 seconds. This time period is adjustable through the Setup
menu and the OSD timeout control described on page 11.
2To highlight a control you want to adjust, press Ior Jto scroll up or down
the Main Menu.
3To select the highlighted control, press button [2]. A control screen appears
like the example shown below.
Contrast
1:EXIT 2: Brightness
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Main Menu Controls
Adjust the menu items shown belowbyusing the up Iand downJ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 Adjust works with most common video cards. If
this function does not work on your LCD dislay, 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.
Color Adjust provides several color options: preset color
temperatures and User which allows you to adjust red (R), green
(G), and blue (B). The factory setting for this product is 6500K
(6500 Kelvin).
6500K — Adds red to the screen image for warmer white and
richer red. Default setting.
9300K — Adds blue to the screen image for cooler white (used
in most office settings with fluorescent lighting).
sRGB —sRGB 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.
5400K — Adds green to the screen image for a darker color.
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Information displays the timing mode (video signal input)
coming from the graphics card in your computer. See your
graphic card’s user guide for instructions on changing the
resolution and refresh rate (vertical frequency).
VESA 1280 x 1024 @ 60 Hz (recommended) means that the
resolution is 1280 x 1024 and the refresh rate is 60 Hertz.
Control Explanation
i
Manual Image Adjust
The Image Adjust controls are explained below:
1To select color (R, G or B) press button [2].
2To adjust selected color, press Ior J.
3When you are finished making all color adjustments, press
button [1] twice.
User — Individual adjustments for red, green, and blue.
Input Select allows you to toggle between an analog and a
digital signal.
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.
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Fine Tune sharpens focus by aligning the illuminated text and/
or graphic characters.
NOTE: Try the Auto Adjust (see page 9) before using the Fine
Tune control.
Sharpness adjusts the clarity and focus of the screen image.
Setup Menu displays the menu shown below.
Control Explanation
the menus and control screens.
The Setup Menu controls are explained below.
Resolution Notice advises the optimal resolution to use.
Language Select allows you to choose the language used in
?
H. Size (Horizontal Size) adjusts the width of the screen image.
NOTE: Vertical size is automatic with your LCD dislay.
H./V. Position adjusts horizontal and vertical position of the
screen image. You can toggle between Horizontal and Vertical
by pressing button [2]. Horizontal moves the screen image to
the left or to the right. Vertical moves the screen image up and
down.
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