ViewSonic VG2021wm-2 Service manual

Service Manual

ViewSonic VG2021wm-2

Model No. VS11425

20” Color TFT LCD Display

(VG2021wm-2_SM Rev. 1a Dec. 2006)

ViewSonic 381 Brea Canyon Road, Walnut, California 91789 USA - (800) 888-8583

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

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 12/1/2006 Initial Release Jamie Chang

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TABLE OF CONTENTS

1. Precautions and Safety Notices 1

2. Specification 3

3. Front Panel Function Control Description 10

4. Circuit Description 16

5. Adjustment Procedure 20

6. Troubleshooting Flow Chart 35

7. Block Diagram 39

8. Schematic Diagrams 40

9. PCB Layout Diagrams 50

10. Exploded Diagram and Exploded Parts List 58

11. Recommended Spare Parts List 62

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1. Precautions and Safety Notices

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) Disconnect the power plug from AC outlet if the product is not used for a long period of

time.

(5) If smoke, abnormal noise, or strange odor is present, immediately switch the LCD display

off. (6) Do not touch the LCD panel surface with sharp or hard objects. (7) Do not place heavy objects on the LCD display, video cable, or power cord. (8) Do not use abrasive cleaners, waxes or solvents for your cleaning. (9) Do not operate the product under the following conditions:

- Extremely hot, cold or humid environment.

- Areas susceptible to excessive dust and dirt.

- Near any appliance generating a strong magnetic field.

- Place 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. Power Supply Requirements

The external AC power operating range shall be from 90 to 264Vac

5. LCD Module Handling Precautions

5.1. Handling Precautions

(1) Since front polarizer is easily damaged, pay attention not to scratch it. (2) Be sure to turn off power supply when inserting or disconnecting from input connector. (3) Wipe off water drop 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 CMOS LSI is used in this module, take care of static electricity and insure human

earth when handling. (7) Do not open nor modify the Module Assembly. (8) Do not press the reflector sheet at the back of the module to any directions. (9) In case if a Module has to be put back into the packing container slot after once it was

taken out from 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 nor

tilt the Interface Connector of the TFT Module. (11) After installation of the TFT Module into an enclosure (LCD monitor housing, for

example), do not twist nor bend the TFT Module even momentary. At designing the

enclosure, it should be taken into consideration that no bending/twisting forces are

applied to the TFT Module from outside. Otherwise the TFT Module may be damaged. (12) Cold cathode fluorescent lamp in LCD contains a small amount of mercury. Please

follow local ordinances or regulations for disposal. (13) Small amount of materials having no flammability grade is used in the LCD module.

The LCD module should be supplied by power complied with requirements of Limited

Power Source (IEC60950 or UL1950), or be applied exemption. (14) The LCD module is designed so that the CFL in it is supplied by Limited Current

Circuit (IEC60950 or UL1950). Do not connect the CFL in Hazardous Voltage Circuit.

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5.2. Handling and Placing Methods

Correct Methods: Incorrect Methods:

Only touch the metal frame of the LCD panel or the front cover of the monitor. Do not touch the surface of the polarizer.

Surface of the LCD panel is pressed by fingers and that may cause “Mura”

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2. Specification

1 GENERAL specification

Test Resolution & Frequency 1680x1050 @ 60Hz

Test Image Size Full Size

Contrast and Brightness Controls

Factory Default:

Contrast = 70%, Brightness = 100%

2 VIDEO INTERFACE

Input Connector (refer the Appendix A) DB-15

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 Pin out Refer to Appendix A; Compliant DDC/2B

Video RGB (Analog)

Video Signals

Separate Sync / Composite Sync / SOG

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/2B Compliant with version 3

Sync Compatibility Separate Sync / Composite Sync / SOG

Shall be compatible with all PC type computers, Macintosh

Video Compatibility

computers, and after market video cards

Resolution Compatibility Refer to Segment 5

Exclusions Not compatible with interlaced video

3 USB INTERFACE

No USB interface

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4 POWER SUPPLY

Internal Power Supply HJC H0AU032001 Input Voltage Range 90 to 264 VAC Input Frequency Range 47 to 63 Hertz Short Circuit Protection Output can be shorted without damage Over Current Protection 5.0 A typical at 12.0 VDC Leakage Current 3.5mA (Max) at 254VAC / 60Hz Efficiency (at 115VAC Full Load) Typical: 80%

Minimum: 75% Fuse Internal and not user replaceable Power Output 38 Watts (typ)

Ripple and Noise

Max Input AC Current 1.5 Arms @ 90VAC, 0.75 Arms @180VAC

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

Power Saving Operation(Method) VESA DPMS Signaling

Power Consumption

Recovery Time On Mode = N/A, Active Off < 3 sec

Ripple: <3%

Noise: <1%

50 A (max) @ 115VAC

90 A (max) @ 230VAC

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 C62.41-1980 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 defined to be in compliance with

ISO 7779 (DIN EN27779:1991) Noise measurements of machines

acoustics. Power Switch noise shall not be considered.

Mode LED Power Consumption

On Blue

Active off Amber <1W

Off Off <1W

With Audio

50W (typ) 55W (max)

Without Audio

43W (typ) 48W (max)

5 ELECTRICAL REQUIREMENT

Horizontal / Vertical Frequency

Horizontal Frequency

Vertical Refresh Rate

Maximum Pixel Clock 165 MHz

Sync Polarity Independent of sync polarity

24 – 82 kHz

50 – 85 Hz

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Timing Table

SOG

Digital - TMDS

Remark

For SOG sync, switch 640x400@60Hz and 640x480@60Hz by [1]+[2] short cut key (primary=640x480@60Hz) For Analog sync, OSD will be 640x400@70Hz/720x400@70Hz. (Promary=720x400@70Hz)

For SOG sync, switch 640x400@60Hz and 640x480@60Hz by [1]+[2] short cut key (primary=640x480@60Hz)

For Analog sync, OSD will be 640x400@70Hz/720x400@70Hz. (Promary=720x400@70Hz)

For SOG sync, the Information OSD will be 1024x768@50Hz, the OSD content also can be changed to 1280x768@50Hz by [1]+[2] short cut key. For SOG sync, the Information OSD will be 1024x768@60Hz, the OSD content also can be changed to 1280x768@60Hz by [1]+[2] short cut key.

For SOG sync, the Information OSD will be 1024x768@75Hz, the OSD content also can be changed to 1280x768@75Hz by [1]+[2] short cut key.

Analog

Composite

Item

Timing

1 640 x 350 @ 70 Hz, 31.5 KHz 　　　　 For SOG sync, OSD will be 720x400@70Hz.

640 x 400 @ 60 Hz, 31.5 KHz

640 x 400 @ 70 Hz, 31.5 KHz

4 640 x 480 @ 50 Hz, 24.7 KHz 　　　　

640 x 480 @ 60 Hz, 31.5 KHz

6 640 x 480 @ 67 Hz, 35 KHz 　　　　 7 640 x 480 @ 72 Hz, 37.9 KHz 　　　　 8 640 x 480 @ 75 Hz, 37.5 KHz 　　　　 9 640 x 480 @ 85 Hz, 43.3 KHz 　　　　

720 x 400 @ 70 Hz, 31.5 KHz

11 720 x 480 @ 60 Hz, 31.5 KHz 　 12 720 x 576 @ 50 Hz, 31.3 KHz 　 13 800 x 600 @ 50 Hz, 24.7 KHz 　　　　 14 800 x 600 @ 56 Hz, 35.1 KHz 　　　　 15 800 x 600 @ 60 Hz, 37.9 KHz 　　　　 16 800 x 600 @ 70 Hz, 43 KHz 　　　　 17 800 x 600 @ 72 Hz, 48.1 KHz 　　　　 18 800 x 600 @ 75 Hz, 46.9 KHz 　　　　 19 800 x 600 @ 85 Hz, 53.7 KHz 　　　　 20 832 x 624 @ 75 Hz, 49.7 KHz 　　　　

1024 x 768 @ 50 Hz, 39.6 KHz

1024 x 768 @ 60 Hz, 48.4 KHz

23 1024 x 768 @ 70 Hz, 56.5 KHz 　　　　 24 1024 x 768 @ 72 Hz, 58.1 KHz 　　　　

1024 x 768 @ 75 Hz, 60 KHz

26 1024 x 768 @ 85 Hz, 68.7 KHz 　　　　 27 1152 x 864 @ 75 Hz, 67.5 KHz 　　　　 28 1152 x 870 @ 75 Hz, 68.7 KHz 　　　　 29 1280 x 720 @ 50 Hz, 37.5 KHz 　　 30 1280 x 720 @ 60 Hz, 45 KHz 　　

1280 x 768 @ 50 Hz, 39.6 KHz

1280 x 768 @ 60 Hz, 47.8 KHz

1280 x 768 @ 75 Hz, 60.3 KHz

34 1280 x 960 @ 50 Hz, 49.4 KHz 　　　　

Separated

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35 1280 x 960 @ 60 Hz, 59.7 KHz 　　　　 36 1280 x 960 @ 75 Hz, 75.2 KHz 　　　　 37 1280 x 1024 @ 60 Hz, 64 KHz 　　　　 38 1280 x 1024 @ 75 Hz, 80 KHz 　　　　

1400 x 1050 @ 60 Hz, 65.3 KHz

40 1440 x 900 @ 60 Hz, 55.5 KHz 　　　　 41 1440 x 900 @ 75 Hz, 75 KHz 　　　　 42 1600 x 1200 @ 60 Hz, 75 KHz 　　　　

1680 x 1050 @ 60 Hz, 64.7 KHz

*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.

For Analog sync, switch 1680x1050@60Hz and 1400x1050@60Hz by [1]+[2] short cut key (primary=1680x1050@60Hz)

7 AUDIO INTERFACE (SPEAKER SPECIFICATION)

Speaker specification

Line input connection 3.5 mm stereo jack

Line input signal 1.0 Vrms

Line input impedance 10 kOhm

Maximum power output (Electric) 2 W / ch

Signal to Noise Ratio 50 dB

Frequency response 100 Hz – 20 Khz

Distortion < 10 % THD (@1kHz)

There should be no audible vibration with volume at 100%

Vibration

and treble / bass at default.

There should be no affect on the screen image stability

Screen image

under any conditions.

Connector PC99 requirement Audio in Lime Green pantone # 577C

Cable type / length 3.5mm stereo cable / 1.8m length

Speakers should be off when the rest of the monitor is in

Audio DPMS

power saving.

* No any sympathetic or abnormal noise allowed.

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8 TFT LCD PANEL

1st Source Panel

Model number AUO M201EW02 V0

Type Active Matrix TFT, TN technology

Active Size 20.1” Wide

Pixel Arrangement RGB Vertical Stripe

Pixel Pitch 0.258 mm

Glass Treatment Anti-Glare, Hard coating (3H)

# of Backlights 6 CCFL

Backlight Life 60000 Hrs (Typ)

50000 Hrs (Min)

300 cd/m2 (Typ after 30 minute warm up) Luminance (Center) –

CT = 6500K,

Contrast/ Brightness = Max

Brightness Uniformity 80 % (Typ) / 75 % (Min)

Contrast Ratio 800 :1 (Typ)

600 : 1 (Min)

Color Depth 16.7 million colors (6 bits + Hi FRC)

Horizontal Viewing Angle 160 degrees (Typ)

Vertical Viewing Angle 160 degrees (Typ)

Response Time On-Off

10%-90% @ Ta=25°C 5ms (Typ) / 8ms (Max)

Mercury 3.0 mg per lamp

Panel Defects Please see Panel Quality Specifications.

*The average of measured value from monthly shipment shall be equal or better than the Typical value above.

240 cd/m2 (Min after 30 minute warm up)

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9 IMAGE PERFORMANCE

Display Size

Horizontal Display Size, Primary Preset Full Screen

Vertical Display Size, Primary Preset Full Screen

Contrast Ratio

CR(Max) –Condition:

Contrast / Brightness = 100%

CCT = USER COLOR (R/G/B=100%)

CR(6500K) –Condition:

Contrast / Brightness = Default

CCT = 6500K

Saturation

Contrast = Default

Brightness = Default

Test pattern = 6gray

Contrast = 100%

Brightness = 100%

Test pattern = 6gray

Preset Color Temperatures

sRGB It should meet IEC 61966-2-1 (1999-10) standard.

Same as the Contrast Ratio in section 6 “TFT LCD PANEL”

CR(6500K) / CR(Max) ≧ 85%

NO VISIBLE SATURATION

* 50% UNITS OF SHIP≧ MENT SHALL BE EQUAL OR BETTER THAN TYPICAL CR SPEC.

4~6 - LEVEL SATURATION

Preset 1

Preset 2

Preset 3 (Primary)

Preset 4

Preset Color Temperature

Adjustability

* Any gray level and Contrast/Brightness should not get reddish, greenish or bluish.

CCT (typ) = 9300K (u’CCT=0.1888; v’ CCT=0.4457)

CCT (max) = 10250K, CCT (min) = 8500K

Δu’v’<0.01 (@ Full White pattern)

CCT (typ) = 7500K (u’CCT=0.1935; v’ CCT=0.4586)

CCT (max) = 8100K, CCT (min) = 6980K

Δu’v’<0.01 (@ Full White pattern)

CCT (typ) = 6500K (u’CCT=0.1978; v’ CCT=0.4684)

CCT (max) = 6950K, CCT (min) = 6100K

Δu’v’<0.01 (@ Full White pattern)

CCT (typ) = 5400K (u’CCT=0.2044; v’ CCT=0.4808)

CCT (max) = 6185K, CCT (min) = 4935K

Δu’v’<0.01 (@ Full White pattern)

Each color preset shall be adjustable. Red, Green, and Blue shall be

individually controlled.

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10 MECHANICAL

Dimension (Desktop)

Width 493 mm (19.4 inch)

Height (Height adjust to the bottom) 455mm (17.9 inch)

Depth 205mm (8.1 inch)

Monitor Weight 6.8 Kg (15.0 lbs)

*Refer to Figure 1

Dimension (Head Only / Wall Mount)

Width 493 mm (19.4 inch)

Height 388mm (15.3 inch)

Depth 70mm (2.8 inch)

Monitor Weight 6 Kg (13.2 lbs)

*Refer to Figure 1

Ergonomics

Tilt Up From 0º up to 20±1º

Tilt Down From 0º down to -5±1º

Swivel Right No

Swivel Left No

Height Adjust No

Pivot No

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3. Front Panel Function Control Description

Main Menu

with OSD controls

Front Control Panel

shown below in detail

Standby Power On/Off Power light Blue = ON Orange = Power Saving

Audio Mute button turns the sound off

Displays the Main Menu or exits the control screen and saves adjustments.

Scrolls through menu options and adjusts the displayed control. Also a shortcut to display the Contrast adjustment control screen.

Displays the control screen for the highlighted control. Also a shortcut to Auto Image Adjust.

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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 command line at the bottom of the control screen tells what to do next from this screen. You can toggle between control screens, adjust the selected option, or exit the screen.

4. To adjust the setting, 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 1680 x 1050 @ 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.)

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Main Menu Controls

Adjust the menu items shown below by using the up S and down T buttons.

Control Explanation

Auto Image Adjust sizes and centers the screen image automatically.

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 Vol ume 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).

7500K - 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.

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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 1680 x 1050 @ 60Hz (recommended) means that the resolution is 1680 x 1050 and the refresh rate is 60 Hertz.

Manual Image Adjust

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.

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.

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Control Explanation

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 allows the user to enable or disable this notice.

If you enable the Resolution Notice shown above and your computer is set at a resolution other than 1680 x 1050, the following screen appears.

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 “30 second” setting, if a control is not pushed within 30 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.

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Short Cut Key

Function Key : 5 Keys !!!! 1 2 ▼

[1] Main Menu

[2] Auto Image Adjust

[;X] Mute

[▼] or [▲]

[▼]+ [▲] recall both of Contrast and Brightness to default

[1] + [2]

[1] + [▼] + [▲] White Balance. (Not shown on user’s guide)

[1] + [▼] Power Lock

[1] + [▲] OSD Lock

[1] + [▼] + [2] Disable Theft Defence function

[▲]+ [ ] + Main Power On All reset

No signal + [ ] + [2] + Main Power on Signal + [2] + [ ] + Main Power On

Remark : All the short cuts function are only available while OSD off

to immediately activate Contrast menu. It should be change to Brightness OSD by push button [2]

toggle 720x400 and 640x400 mode when input 720x400 or 640x400 mode

Burning mode

Factory Mode

▼▼▼

▲▲▲▲

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4. Circuit Description

RTD2553V LCD Monitor/MFM Controller General

Embedded dual DDC with DDC1/2B/CI　 Zoom scaling up and down　 No external memory required.　 Require only one crystal to generate all timing.　 Programmable 3.3V/5V detection reset　 output. Embedded crystal output to micro　 -controller. 3 channels 8 bits PWM output, and wide range　 selectable PWM frequency.

Analog RGB Input Interface

Integrated 8　 -bit triple-channel 210/165 (optional) MHz ADC/PLL Embedded programmable Schmitt　 trigger of HSYNC Support Sync On Green (SOG) and various kinds　 of composite sync modes On　 -chip high-performance hybrid PLLs High resolution true 64 phase ADC PLL　 Y/Pb/Pr support up to HDTV 1080i resolution　 Support 2/1 Analog input (optional　 )

Digital Video Input Interface

Support 8　 -bit video (ITU 656) format input Support 16　 -bit video (ITU 601) format input (optional) Built　 -in YUV to RGB color space converter & de-interlace

DVI Compliant Digital Input Interface (optional)

Single l　 ink on-chip TMDS receiver Support to 165Mhz with long cable　 Adaptive algorithm for TMDS capability　 Data enable only mode support　 High　 -Bandwidth Digital Content Protection (HDCP 1.1) (optional only in H version) Enhanced protection of HDCP se　 cret key (optional only in H version)

Auto Detection /Auto Calibration

Input format detection　 Compatibility with standard VESA mode and　 support user-defined mode Smart engine for Phase/Image position/Color　 calibration

Scaling

Fully programmable　 zoom ratios Independent horizontal/vertical scaling　 Advanced zoom algorithm provides high image　 quality Sharpness/Smooth filter enhancement　 Support non　 -linear scaling from 4:3 to 16:9 or 16:9 to 4:3

Vivid Color.

Dynamic Contrast Control (DC　 C) Independent Color Management (ICM)　 True 10 bits color processing engine　 sRGB compliance　 Advanced Dithering logic for 18　 -bit panel color depth enhancement Dynamic overshoot　 -smear canceling engine Brightness and contrast control　 Progr　 ammable 10-bit gamma support

Output Interface

Fully programmable display timing generator　 Flexible data pair swapping for easier system　 design. Programmable TCON function support　 Multi　 -output interface (RSDS/LVDS/TTL)on single PCB Spread　 -Spectrum DPLL to reduce EMI Fixed Last Line output for perfect panel　 capability

Host Interface

Support MCU serial/parallel bus interface.　 Support MCU dual edge data latch.　

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Embedded OSD

Embedded 12K SRAM dynamically stores OSD　 command and fonts Supp　 ort multi-color RAM font, 1, 2 and 4-bit per pixel 16 color palette with 24bit true color selection　 Maximum 8 window with alpha　 -blending/gradient/dynamic fade-in/fade-out, bordering/shadow/3D

window type

Rotary 90,180,270 degree　 Independent r　 ow shadowing/bordering Programmable blinking effects for each character　 OSD　 -made internal pattern generator for factory mode Support 12x18~4x18 proportional font　 Decompress OSD font　

Power & Technology

3.3V power supplier　 0.18um CMOS process, 12　 8-pin QFP package Embedded 3.3V to 1.8V voltage regulator　

Analog Input

RTD integrates three ADC’s (analog-to-digital converters), one for each color (red, green, and blue). The sync-processor can deal with Separate-Sync, Composite-Sync, and Sync-On-Green. And the PLL can generate very low jitter clock from HS to sample the analog signal to digital data. Input data is latched within a capture window defined in registers refer to VS and HS leading edge. RTD also has 2 ADC input, we can switch these 2 input to choose which input we want to present on RTD embedded LCD monitor. RTD has a YPbPr input, we can connect DVD or some devices that has YPbPr input, YPbPr input can be 1st or 2nd ADC pins.

TMDS Input

RTD integrates high-speed single link receiver function. It can operate up to 165 M at long cable. RTD integrates an equalizer to enhance the cable loss weakness in long cable application and the advanced tracking algorithm to have better performance in DVI RX.

Display Output Timing

The display output port sends single/double pixel data transfer and synchronized display timing to an external device. The display port also support display panel with 6-bit per color, turn on the dithering function to enhance color depth. In single pixel output mode, single pixel data (24-bit RGB) is transferred to display port A on each active edge of DCLK, the rate of DCLK is also equal to display pixel clock. The sync & enable signals are also sent to display port on each active edge of DCLK. In double pixel output mode, double pixel data (48-bit RGB) is transferred to display port A & B on each active edge of DCLK and the rate of DCLK is equal to half display pixel clock at this moment. The sync & enable signals are also sent to display port on each active edge of DCLK.

Color Processing

Digital color R & G & B independent channel sRGB, contrast, brightness, gamma, dithering controls are built in RTD. sRGB compliance function is provided with 9 multipliers. The contrast control is performed a multiply value from 0 to 2 for each R/G/B channel. The brightness control is used to set an offset value from -512 to +511 also for each R/G/B channel. Also RTD provided 10 bit gamma and a high performance dithering function.

Build-In OSD

The detailed function-description of build-in OSD, please refer to the application note for RTD embedded OSD.

Color LUT & Overlay Port

The following diagram presents the data flow among the gamma correction, dithering, overlay MUX, OSD LUT and output format conversion blocks.

Auto-Adjustment

There are two main independent auto-adjustment functions supported by RTD, including auto-position & auto-tracking. The operation procedure is as following;

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Auto-Position

1. Define the RGB color noise margin: When the value of color channel R or G or B is greater than these noise margins, a valid pixel is found.

2. Define the threshold-pixel for vertical boundary search

3. Define the boundary window of searching for horizontal boundary search.

4. Start auto-function.

5. The result can be read from register.

Auto-Tracking

1. Setting the control-registers for the function (auto-phase, auto-balance) according to the Control-Table.

2. Define the Threshold

3. Define the boundary window of searching for tracking window.

4. Start auto-function.

5. The result can be read from register

PLL System

Inside the RTD, there are four PLL systems for display clock and ADC sample clock (PLL1, PLL2,M2PLL, DPLL ).

DCLK PLL

DPLL frequency = F_IN * DPM / DPN * Divider.

F_IN is input crystal frequency. DPM and DPN is in DPLL_M and DPLL_N. DPLL_N, and it divide PLL frequency by 1, 2, 4 or 8. According to parameter DPN, you must set LPF Mode in DPLL_WD. If LPF Mode is 1, the charge

pump current, Ich, must be DPM/17.6, while Ich must be DPM/1.67 if LPF Mode is 0. The charge

pump current Ich is in DPLL_CRNT.

Spread-Spectrum function is also build in DCLK to reduce EMI. You can control the SSP_I, SSP_W, and FMDIV to fine-tune the EMI. M2PLL is a PLL used to power-on reset, FIFO clock and Internal crystal clock. After power-on reset, M2PLL output 10 times frequency of crystal clock. According to crystal frequency, set M2PLL to keep FIFO clock frequency between 240MHz and 250MHz.

ADC Pixel Sampling PLL

The input pixel sampling PLL of RTD compose of PLL1 and PLL2 and DDS, the hybrid PLL system inherently has a process-independent advantages comparing with pure analog PLL, DDS synthesizer is in charge of the phase-frequency control, PLL1 provided a high frequency to get a larger bandwidth letting the system fast locking, PLL2 finally synthesize the desired pixel sampling clock. The block diagram shown below describes our high-performance tracking system.

Host Interface Parallel/Serial Port Determination:

After RESET end, the status of pin 5 (TMDS_TST) can be sensed to determine the interface mode: high for parallel port, low, low for serial port.

Host Interface Location Determination:

After the falling edge of RESET signal, the status of pin 3 can be sensed to determine the host interface location: high for 112-115,118,119, and low for 52-57

Reset Output

We have the RESET_OUT function, and also reserve the RESET_IN function. By the bounding of internal pins we can select two kinds of reset function. First of all is only reset-out, we can output the reset signal to MCU, and the MCU can reset the RTD by firmware. The second is RTD output reset and also reset itself. Notice that the reset output is positive polarity, besides, the reset output is open-drain pin, please don’t forget to attach a pull-up resistor (10K). The reset function for 3.3V operating voltage detection is determined by 33VRST_REF voltage, No matter 5V or 3.3V MCU is been used, divider the input voltage on 33VRST_REF to 2.2V for internal power sensing circuit detecting, the divider resistor should be 10K level avoiding current leakage.

The Programmable Schmitt Trigger of HSYNC

To get better waveform of the input HSYNC, we have a programmable Schmitt Trigger circuit. For different HSYNC amplitude and polarity, we can select different setting of the threshold voltage. The Vt + and the Vt - can be selected by register CR97 We can select the old mode or the new mode. When using the new mode we can directly determine the positive threshold voltage (1.4V, 1.6V… 2.6V), and we can choose the hysterias from the Vt + to determine the Vt - (0.6V, 0.8V, 1.0V, 1.2V). We also can finely tune the voltage by minus

0.1V. For application, we can select different threshold voltage by the polarity of the HSYNC. The control register is CR97

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Crystal Frequency Output

RTD can output crystal frequency or 1/2 crystal frequency to external MCU to save a crystal device. Once power state is on and reset is finished, we can set crystal frequency by firmware and output to pin 48 and pin 110 simultaneously, and then can turn off them in Pin Share Part. Pin 48 and PIN 110 is configurable, detail setting is listed in Pin-Share part

RTD2120 8051 Embedded Micro-Controller for Monitor

Overview

This chip is the micro-processor of LCD monitor. It uses the design ware DW8051 of Synopsys as the 8051 core of this chip and is compatible with other industry 8051 series. Also, 96Kbyte FLASH with 8 bit bus is embedded in this chip which is licensed from TSMC 0.18um e-FLASH process. Here we use the package of PLCC44/LQFP48 if we would like to have a discrete MCU controller or we make a multi-chip package with our LCD monitor controller to form one chip package to save the cost of package and PCB material.

Features

　Operating voltage range : 3.0V to 3.6V 　8051 core, CPU operating frequency up to 50MHz 　4 clocks per machine cycle 　256-byte internal RAM 　512-byte external data RAM, including 256-byte DDC RAM(128-byte x 2) and 256-byte

general purpose RAM

　96K-byte flash memory, 64k for program and 32k for saving parameter 　Two DDC ports compliant with VESA DDC1/2B/2Bi/CI 　Three channels of PWM DAC with programable frequency from 100K to 100Hz 　Watchdog timer with programmable interval 　Three 16-bit counters/timers (T0, T1, and T2) 　One PLL to provide programmable operating frequency and clock output, 2 clock output ports 　One full-duplex serial port 　Six interrupt sources with 2 external interrupts

 Four channels of 6-bit ADC  Hardware In System Programming(ISP) capability, no boot code required  Built-in Low voltage reset circuit  Embedded 1.8V regulator  Code protection  Available in 44-pin PLCC or 48-pin LQFP package

AUDIO STEREO CLASS-D AUDIO POWER AMPLIFIER

DESCRIPTION

The TPA2008D2 is a third generation 5-V class-D amplifier from Texas Instruments. Improvements to previous generation devices include: dc volume control, lower supply current, lower noise floor, higher efficiency, smaller packaging, and fewer external components. Most notably, a new filter-free class-D modulation technique allows the TPA2008D2 to directly drive the speakers, without needing a low-pass output filter consisting of two inductors and three capacitors per channel. Eliminating this output filter saves approximately 30% in system cost and 75% in PCB area. The improvements and functionality make this device ideal for LCD projectors, LCD monitors, powered speakers, and other applications that demand more battery life, reduced board space, and functionality that surpasses currently available class-D devices. A chip-level shutdown control limits total supply current to 1 µA, making the device ideal for bat- tery-powered applications. Protection circuitry increases device reliability: thermal and short circuit. Undervoltage shutdown saves battery power for more essential devices when battery voltage drops to low leve.

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5. Adjustment Procedure

1. Function Test

1.1 Product

- 20” LCD Monitor

1.2 Test Equipment

- Color Video Signal & Pattern (or PC with WSXGA+ resolution and a sound card)

1.3 Test Condition

Before function test and alignment, each LCD Monitor should be run-in and warmed up for at least 30 minutes with the following conditions: (a) In room temperature, (b) With full-white screen, RGB, and Black (c) With cycled display modes, 640*480 (H=43.27kHz, V=85Hz) 800*600 (H=53.7kHz, V=85Hz) 1024*768 (H=68.67kHz, V=85Hz) 1680*1050 (H=64.7kHz, V=60Hz)

1.4 Test Display Modes & Pattern

1.4.1 Compatible Modes

1. 640 x 350 @ 70Hz, 31.5kHz

2. 640 x 400 @ 60Hz, 31.5kHz

3. 640 x 400 @ 70Hz, 31.5kHz

4. 640 x 480 @ 50Hz, 24.7kHz

5. 640 x 480 @ 60Hz, 31.5kHz

6. 640 x 480 @ 67Hz, 35.0kHz

7. 640 x 480 @ 72Hz, 37.9kHz

8. 640 x 480 @ 75Hz, 37.5kHz

9. 640 x 480 @ 85Hz, 43.27kHz

10. 720 x 400 @ 70Hz, 31.5kHz

11. 720 x 480 @ 60Hz, 31.5kHz

12. 720 x 576 @ 50Hz, 31.3kHz

13. 800 x 600 @ 50Hz, 24.7kHz

14. 800 x 600 @ 56Hz, 35.1kHz

15. 800 x 600 @ 60Hz, 37.9kHz

16. 800 x 600 @ 70Hz, 43 kHz

17. 800 x 600 @ 72Hz, 48.1kHz

18. 800 x 600 @ 75Hz, 46.9kHz

19. 800 x 600 @ 85Hz, 53.7kHz

20. 832 x 624 @ 75Hz, 49.7kHz

21. 1024 x 768 @ 50Hz, 39.6kHz

22. 1024 x 768 @ 60Hz, 48.4kHz

23. 1024 x 768 @ 70Hz, 56.5kHz

24. 1024 x 768 @ 72Hz, 58.1kHz

25. 1024 x 768 @ 75Hz, 60 kHz

26. 1024 x 768 @ 85Hz, 68.7 kHz

27. 1152 x 864 @ 75Hz, 67.5 kHz

28. 1152 x 870 @ 75Hz, 68.7 kHz

Analog

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+ 51 hidden pages

ViewSonic VG2021wm-2 Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1. Precautions and Safety Notices

2. Specification

4. Circuit Description

5. Adjustment Procedure