ViewSonic VG170mVLCDS23724-3W User manual

Model No. VLCDS23724-3W
17” Color TFT LCD Display
Service Manual
ViewSonic VG170m
ViewSonic
381 Brea Canyon Road, Walnut, California 91789 USA - [phone]
(VG170m-1_SM_625 Rev. 1a – Jan.2004)

Copyright
Copyright
¤
2003by 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.
Revision History
Revision Date Description Of Changes Approval
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.
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1b07/01/04 Revise DCN- 3755 Angela Luh
1a 11/05/02 Initial Release DCN- 2776 C Shen

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
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11. PCB Layout Diagrams
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1. Precautions and Safety Notices
Prior to using this manual, please ensure that you have carefully followed all the procedures outlined in the user manual for
this product.
Read all of these instructions.
Save these instructions for later use.
Follow all warnings and instructions marked on the product.
Do not use this product near water.
This display should be installed on a solid horizontal base.
When cleaning, use only a neutral detergent cleaner with a soft damp cloth. Do not spray with liquid or aerosol cleaners.
Do not expose this display to direct sunlight or heat. Hot air may cause damage to the cabinet and other parts.
Adequate ventilation must be maintained to ensure reliable and continued operation and to protect the display from
overheating. Do not block ventilation slots and openings with objects or install the display in a place where ventilation may
be hindered.
Do not install this display near a motor or transformer where strong magnetism is generated. Images on the display will
become distorted and the color irregular.
Do not allow metal pieces or objects of any kind fall into the display from ventilation holes.
Slots and openings in the cabinet and the back or bottom are provided for ventilation, to ensure reliable operation of the
product and to protect it from overheating, those openings muse not be blocked or covered. The openings should never be
blocked by placing the product on a bed, sofa, rug, or other similar surface. This product should never be placed near or over
a radiator or heat register. This product should not be placed in a built-in installation unless proper ventilation is provided.
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2. Specification
2.1. PRODUCT SPECIFICATIONS
LCD panel type 17.0”TFT(AU)
Power Consumption 40 W
Displayable Resolution SXGA 1280 x 1024 maximum
Pixel dimension 0.264 mm x 0.264 mm
Display Color 16.7 M
Viewing Angle
(CR≥10) Horizontal: ±70°
Vertical: ±70°
Response Time Tr:12ms Tf:4ms( typ).
Contrast Ratio 450:1 typ.
Brightness 200 cd/m2(min),260 cd / m2typ.
Active Display Area 337.9 mm horizontal x 270.3mm vertical
AC/DC adapter Input:AC 100~264V,47~63 Hz
Output:+12V DC.
Dimensions ( WxHxD ) 415 mm(W) x 403(H) mm x 229(D) mm
Weight (Net / Gross) 5.4/7.6 kg (unit)
Input connector 15 Pin D-Sub.
Power management YES
Temperature
Operating : 0°C ~ +40°C
Storage : -20°C ~ +60°C
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2.2. FACTORY SUPPORTING MODES
Primary Preset VESA 1280 x 1024 @ 60 Hz
Factory Preset Modes
1. VESA 640 x 350 @ 70Hz, 31.47kHz, -/+
2. VESA 720 x 400 @ 70Hz, 31.467kHz, +/-
3. VESA 640 x 480 @ 60Hz, 31.469kHz, -/-
4. VESA 640 x 480 @ 72Hz, 37.861kHz, -/-
5. VESA 640 x 480 @ 75Hz, 37.5kHz, -/-
6. MAC 640 x 480 @ 67Hz, 35kHz,
7. VESA 800 x 600 @ 56Hz, 35.156kHz, +/+
8. VESA 800 x 600 @ 60Hz, 37.879kHz, +/+
9. VESA 800 x 600@ 72Hz, 48.077kHz,+/+
10. VESA 800 x 600 @ 75Hz, 46.875kHz, +/+
11. MAC 832 x 624 @ 75Hz, 49.725kHz,
12. VESA1024 x 768 @ 60Hz, 48.363kHz, -/-
13. VESA1024 x 768 @ 70Hz,56.476kHz, -/-
14. VESA 1024 x 768 @ 72Hz, 58.036kHz, -/-
15. VESA 1024 x 768 @ 75Hz, 60.023kHz, +/+
16. MAC 1024 x 768 @ 75Hz, 60.241kHz,
17. VESA 1280 x 1024 @ 60Hz, 63.981kHz, +/+
18. VESA 1280 x 1024 @ 75Hz, 79.976kHz, +/+
19. MAC 1152 x 870 @ 75Hz, 68.6kHz,
2.3. D-SUB CONNECTOR
Thissectiondescribesthepinassignment of the LCD’s video connector. It is called 15 Pin Mini D-sub Connector.
Pin NO. Signal Connector
1 Red Video Signal
2 Green Video Signal
3 Blue Video Signal
4 N.C.
5 Ground
6 Ground
7 Ground
8 Ground
9 +5v
10 Ground
11 N.C.
12 DDC data
13 Horizontal sync signal
14 Vertical sync signal
15 DDC clock
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3. Front Panel Function Control Description
Location of Controls
MUNT [1]MENU ADJUST ▲ LED POWER
;-VOL -[2]ENTER
;+ VOL+ ADJUST ▼
1) POWER :
Press the power button to turn the monitor on. Press it again to turn the monitor off.
2) [1]MENU :
Enter or exit the OSD adjustment menu.it also exit from the submenu back to previous menu.
3) [2]ENTER :
To confirm the current selection
4) ADJUST
▲(UP)
To scroll up in menu or to increase value of selected item.
5) ADJUST ▼:(DOWN)
To scroll down in menu or to decrease value of selected item.
6) MUNT: Temporarilysilences audio output.
7) ;-VOL -: Decreases or increase volume.
8) ;+ VOL+: Decreases or increase volume.
9)POWER INDICATOR :
The LED will lightwith green color in normal onstate,andwill lightwith orange color in power savingmode.
10) Brightness/Contrast:press button UP/DOWN .
11) AutoImage Adjust :press button [2] .
12) OSD lock and unlock: press two buttons [1]&[up] simultaneouslyfor 10 seconds.
13) Power lock and unlock: press two buttons [1]&[Down] simultaneouslyfor 10 seconds.
14) ALL RESET: First, power off the monitor, un-plug the AC cord, then press “▲” and “Power “ key at the same
time and plug the AC cord.
15) Factory Mode:First, power off the monitor, un-plug the AC cord and be sure the signal cableisconnected(D-sub
connected) , then press “2” and “Power “ key at the sametime and plug the AC cord.
16) RUN-IN mode: First, power off the monitor, un-plug the AC cord and be sure the signal cableisnot connected (D-sub
not connected) , then press “2” and “Power “ key at the sametime and plug the AC cord.
17) ISP mode:First, power off the monitor, unplug the AC cord, then press “2” and “Power “ and “down” key at the same
time and plug the AC cord.
18) AUTO color: then press “1” and “▲“ and “▼” key at the same time.
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4 Circuit Description
A. DC-DC CONVERTER AND LDO
Thisbrick converts the 12V input voltage to 5V for panel use and U9 converts the voltage from 5V to 3.3V ,U8 converts
the voltage from 5V to 2.5V for controller use.
It consists of a PWM IC (LM2596), flywheel Diode (D4), buck choke (L1), and capacitor (C68,C69).
U7 (LM2596) is a PWM generator working at 150Khz.
Self protection features include a two stage frequency reducing current limitfor the output switch and an over temperature
shutdown for complete protection under fault condition.
U8 isa low dropout voltage and fast trasient response three terminal regulator, the output voltage is2.5V fixed.
U9 isa low dropout voltage and fast trasient response three terminal regulator, the output voltage is3.3V fixed.
B. Scaling controller
The gm2121 isa graphics processing IC for Liquid CrystalDisplay(LCD) monitor at SXGA resolution . It provides a
high-speed triple-ADC andPLL,a highquality zoomandshrinkscalingengine , an on-screen display (OSD) controller,
digital color controls, an on-chip micro-controller ( OCM ) and industry standard dual four channel LVDS transmitter for
direct connect to LCD panel with LVDS interface.
The triple-ADC istoconvert RGB analog signal todigitalsignal. The gm2121 isa complete8-bitup to162MHz
(SXGA 75Hz / UXGA 60Hz) monolithic analog interface optimized for capturing RGB graphic signal, +3.3V and +2.5V
power supply is necessary.
The gm2121 scaling filter can combine it’s advanced scaling with a pixel-replication type scaling function.this is useful for
improving the sharpness and definition of graphics when scaling at high zoom factors. Gm2121 provides an 8 to 10 bit
look-up table (LUT) for each input color channel intended for Gammacorrection and to compensate for a non-linear
response of the LCD panel . A 10-bitoutput resultsin an improved color depth control. The 10-bitoutput isthen dithered
down to 8 bits( or 6 bits) per channel at the display .
C. AMP
The APA4835 is a monolithic integrated circuit , which provides DC volume control , and a stereo bridged audio power
amplifiers capableof producing 2W (2.2W) into 4Ωwithless than 10% (1.0%) THD+N. APA4835 includes a DC volume
control , stereo bridge-tied and single-ended audio power amplifiers , stereo docking outputs , and a selectablegaincontrol,
that makes it optimally fittable for notebook PC, multimedia monitors , and other portable applications.
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5. Adjusting Procedure
First, power off the monitor, un-plug the AC cord and be sure the signal cable is connected(D-sub connected),
then press “2” and “Power “ key at the same time and plug the AC cord to factory.
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6. Trouble Shooting Flow Chart
YES
NO
ON
OFF
GREEN Hsync,Vsync
or DE error
ORANGE
OSD no respones
Too dim
The brightness is
different between upper
and lower side of panel
Partial picture without
Color
Vertical,Horizontal
None synchronousness
A few of colorfully
Vertical lines
Even(or odd) vertical
Line is dark
Check SW board S1~S5
Check OSD adjustment
Check inverter
Check backlight
Check signal cable
Check I/F board
Check LCD panel
Check LCD panel
Check I/F board
Check SW board
JP1
Check inverter
Check I/F board
Check
power
LED
Check display
resolution Check inverter
Check I/F board CN1 Check LCD cable
Check I/F board CN1
Check LCD panel J1
Check I/F board
A dark picture
or a picture
full of
colorfully
vertical lines
Does
picture
display
Back-light
On or off?
RGB SIGNAL
ERROR
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