Viewsonic VA902-2 Service Manual 1a

Service Manual

ViewSonic VA902-2

VA902b-2

Model No. VS10715

19” Color TFT LCD Display

(VA902-2_VA902b-2_SM Rev. 1a Jan. 2006)

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

Copyright © 2005 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

1a 01/16/2006 Initial Release Jamie Chang

Description of Changes Editor

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TABLE OF CONTENTS

1. Precautions and Safety Notices 1

2. Specification 4

3. Front Panel Function Control Description 7

4. Circuit Description 14

5. Adjustment Procedure 21

6. Troubleshooting Flow Chart 40

7. Recommended Spare Parts List 43

8. Exploded Diagram and Exploded Parts List 53

9. Block Diagrams 56

10. Schematic Diagrams 57

11. PCB Layout Diagrams 65

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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.

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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.

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.

Take out the monitor with cushions Taking out the monitor by grasping the LCD

Surface of the LCD panel is pressed by fingers

and that may cause “Mura”

panel. That may cause “Mura”

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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”

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2. Specification

1. General Requirements

General Specifications

Test Resolution & Frequency “1280 x 1024” @ 60Hz Test Image Size Full Size Contrast and Brightness Controls Factory Default:

Contrast = 70%, Brightness = 100%

2. Signal Interface

Video Interface

Analog Input Connector DB-15 (Analog) Default Input Connector Defaults to the first detected input Video Cable Connector DB-15 Pin out Compliant DDC 1/2B. Video Signals 1. Video RGB (Analog) Separate Sync Video Impedance 75 Ohms (Analog), 100 Ohms (Digital)

Exclusions Not compatible with interlaced video.

3. Power

Power Supply

Input Voltage Range 90 to 264 VAC Power Dissipation 40 Watts (Typ.)

4. Electrical Requirements

Horizontal / Vertical Frequency

Horizontal Frequency 30 – 82 KHz Vertical Refresh Rate 50 – 85 Hz

* For resolution 1280 x 1024, the vertical

Refresh rate up to 75 Hz; for there rest Resolutions, the vertical refresh rate up To 85Hz

Maximum Pixel Clock 135 MHz

Sync Polarity Independent of sync polarity.

Timing Table

Item Timing Analog

1 640 x 350 @ 70Hz, 31.5kHz Yes 2 640 x 400 @ 60Hz, 31.5kHz Yes 3 640 x 400 @ 70Hz, 31.5kHz Yes 4 640 x 480 @ 50Hz, 24.7kHz Yes 5 640 x 480 @ 60Hz, 31.5kHz Yes 6 640 x 480 @ 67Hz, 35.0kHz Yes 7 640 x 480 @ 72Hz, 37.9kHz Yes 8 640 x 480 @ 75Hz, 37.5kHz Yes

9 640 x 480 @ 85Hz, 43.27kHz Yes 10 720 x 400 @ 70Hz, 31.5kHz Yes 11 800 x 600 @ 56Hz, 35.1kHz Yes 12 800 x 600 @ 60Hz, 37.9kHz Yes 13 800 x 600 @ 75Hz, 46.9kHz Yes 14 800 x 600 @ 72Hz, 48.1kHz Yes 15 800 x 600 @ 85Hz, 53.7kHz Yes 16 832 x 624 @ 75Hz, 49.7kHz Yes 17 1024 x 768 @ 60Hz, 48.4kHz Yes 18 1024 x 768 @ 70Hz, 56.5kHz Yes 19 1024 x 768 @ 72Hz, 58.1kHz No 20 1024 x 768 @ 75Hz, 60.0kHz Yes

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21 1024 x 768 @ 85Hz, 68.67kHz Yes 22 1152 x 864 @ 75Hz, 67.5kHz No 23 1152 x 870 @ 75Hz, 68.7kHz Yes 24 1280 x 1024 @ 60Hz, 63.4kHz Yes 25 1280 x 1024 @ 75Hz, 79.97kHz Yes 26 1280x 720 @ 60Hz, 45kHz (HDTV) Yes

Changing Modes

Maximum Mode Change Blank Time for image stability. Note:

1) Excluding “Auto Adjust” time

2) Under DOS mode (640 x 350, 720 x 400 & 640 x

Under 3 seconds (Maximum) 1 seconds (Typ.) for recognized timings 1-2 seconds (Typ.) for unrecognized timing

400), there is no “Auto Adjust” feature.

3) The monitor needs to do “Auto Adjust” the first

time a new mode is detected.

5. LCD Panel

Panel Characteristics

Panel Type M190EN03V3 Type VA type with LVDS interface Active Size 376.32 (H) x 301.056 (V) Pixel Arrangement RGB Vertical Stripe Pixel Pitch 0.294 mm # of Backlights 4 CCFL edge-light (2 top / 2 bottom) Backlight Life 40,000 Hours (minimum) Panel Performance

Luminance – Condition: CT = 6500K, Contrast = Max,

250 cd/m

2 (typ. after 30-minute warm-up)

200 cd/m2 (minimum after 30-minute warm-up)

Brightness = Max Brightness Uniformity 80% (typ)

75% (min)

Contrast Ratio 1000:1 (typ.), 750:1 (minimum) Color Depth 16.7M colors (RGB 8-bit data) Viewing Angle (Horizontal) 170 degrees @ CR>10 Viewing Angle (Vertical) 170 degrees @ CR>10

Response Time 10%-90% @ Ta=25°C

14 ms (Tr= 9 ms, Tf = 5 ms) (typ.)

40 ms (Tr= 25 ms, Tf =15 ms) (maximum)

6. Mechanical

Dimensions

Width 414 mm Height 407 mm Depth 219 mm Monitor Weight 5.4kg / 11.88 lbs

Ergonomics

Tilt Up 20 DEGREES MINIMUM Tilt Down -5 degrees

Package Specifications

Width 490 mm Height 570 mm Depth 145 mm Gross Weight 6.8kg (14.96lb)

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7. Environmental

Environmental Conditions

Operating Temperature 0°C to +40°C Storage Temperature -20°C to +60°C Operating Relative Humidity 10% to 90% RH Non-Condensing Storage Relative Humidity 5% to 90% RH Non-Condensing Operating Altitude 0 to +3,000 meters Storage Altitude 0 to +12,000 meters

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3. Front Panel Function Control Description

Main Menu With OnView 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

Power On/Off

Scrolls through menu options and adjusts the displayed control.

Also a shortcut to display the Contrast adjustment control screen.

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Do the following to adjust the screen image:

To display the Main Menu, press button [1].

Main Menu

AUTO

SET

1:EXIT 2:SELECT

Auto Adjust

Contrast/Brightness

Color Adjust

Information

Image Adjust

Setup Menu

Memory Recall

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.

To highlight a control you want to adjust, press I or J to scroll up or down the Main Menu.

To select the highlighted control, press button [2]. A control screen appears like the example shown below.

Contrast

1:EXIT 2: Brightness

To adjust the control, press the upIor downJbuttons.

To save the adjustments and exit the menu, press button [1] twice.

The line at the bottom of the screen tells you what you can do next: Exit or Select the control that is highlighted.

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

. (The black border around the edge of the screen should barely touch the illuminated “active area” of the LCD dislay.)

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Main Menu Controls

Adjust the menu items shown below by using the up Iand down Jbuttons.

Control Explanation

Auto 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

Color Adjust

adjusts background black level of the screen image.

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).

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.

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. Default setting.

5400K — Adds green to the screen image for a darker color.

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Control Explanation

User

— Individual adjustments for red, green, and blue.

To select color (R, G or B) press button [2].

To adjust selected color, press I or J.

When you are finished making all color adjustments, press button [1] twice.

Information

coming from the graphics card in your computer. See your

displays the timing mode (video signal input)

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.

Image Adjust

H./V. Position

H. Size

Fine Tune

Sharpness

1:EXIT 2:SELECT

The Image Adjust controls are explained below:

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.

H. Size

NOTE:

(Horizontal Size) adjusts the width of the screen image.

Vertical size is automatic with your LCD dislay.

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Control

Explanation

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

Setup Menu displays the menu shown below.

adjusts the clarity and focus of the screen image.

The Setup Menu controls are explained below.

anguage

Select allows you to choose the language used in

the menus and control screens.

OSD

Resolution Notice

OSD Position

advises the optimal resolution to use.

allows you to move the on-screen display menus

and control screens.

OSD Timeout

sets the length of time an on-screen display screen is displayed. For example, with a “15 second” setting, if a control is not pushed within 15 seconds, the display screen disappears.

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Control Explanation

OSD

OSD Background

allows you to turn the On-Screen display background on or off. This means that while making adjustments from the OSD control screens you can also view open software applications, or the Windows desktop.

Memory Recall

returns adjustments to the original factory settings if the display is operating in a factory Preset Timing Mode listed in this user guide.

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Short Cut Key

Function Key : 5 Keys !!!! 1 2 ▼

▼▼▼

[1] Main Menu [2] Auto Image Adjust

[▼▼▼▼] or [▲▲▲▲]

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

[▼▼▼▼] + [▲▲▲▲]

recall Contrast or Brightness while in the Contrast or Brightness adjustment, or recall both of Contrast and Brightness when the OSD is not open.

[1] + [2] toggle 720x400 and 640x400 mode when

input 720x400 or 640x400 mode.

[1] + [▼▼▼▼] + [▲▲▲▲]

(Keep pushing 5 sec)

[1] + [▼▼▼▼] [1] + [▲▲▲▲]

White Balance.

Power Lock OSD Lock

▲▲▲▲

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4. Circuit Description

A. Scaling controller

GENERAL DESCRIPTION

The TSU16AS is total solution graphics processing IC for LCD monitors with panel resolutions up to SXGA. It is configured with a high-speed integrated triple-ADC/PLL, a high quality display processing engine, and an integrated output display interface that can support LVDS panel interface format. To further reduce system costs, the TSU16AS also integrates intelligent power management control capability for green-mode requirements and spread-spectrum support for EMI management. The TSU16AS incorporates the world’s first coherent oversampled RGB graphics ADC in a monitor controller system1. The oversampling ADC samples the input RGB signals at a frequency that is much higher than the signal source pixel rate. This can preserve details in the video signal that ordinarily would be lost due to input signal jitter or bandwidth limitations in non-oversampled systems. The TSU16AS also incorporates a new Dynamic Frame Rate (DFR) generator2 for the digital output video to the display panel that preserves the advantages of a fixed output clock rate, while eliminating the output end of frame short-line. 1,2 Patent Pending

PIN DESCRIPTION CPU Interface Pin Name Pin Type Function Pin

HWRESET Schmitt Trigger Input w/ 5V-tolerant Hardware reset; active high 5 INT Output CPU interrupt; 4mA driving strength 27 AD3 I/O w/ 5V-tolerant DDR direct bus AD3; 4mA driving strength 4 AD2 I/O w/ 5V-tolerant DDR direct bus AD2; 4mA driving strength 1 AD1 I/O w/ 5V-tolerant DDR direct bus AD1; 4mA driving strength 2 AD0 I/O w/ 5V-tolerant DDR direct bus AD0; 4mA driving strength 3 ALE I w/ 5V-tolerant DDR direct bus ALE; active high 24 WRZ I w/ 5V-tolerant DDR direct bus WRZ; active low 25 RDZ I w/ 5V-tolerant DDR direct bus RDZ; active low 26

Analog Interface Pin Name Pin Type Function Pin

HSYNC Schmitt Trigger Input w/ 5V-tolerant Analog HSYNC input 8 VSYNC Schmitt Trigger Input w/ 5V-tolerant Analog VSYNC input 9 REFP Internal ADC top de-coupling pin 22 REFM Internal ADC bottom de-coupling pin 23 RINP Analog Input Analog red input 19 RINM Analog Input Reference ground for analog red input 18 SOGIN Analog Input Sync-on-green input 17 GINP Analog Input Analog green input 16 GINM Analog Input Reference ground for analog green input 15 BINP Analog Input Analog blue input 14 BINM Analog Input Reference ground for analog blue input 13 REXT External resistor 390 ohm to AVDD_ADC 11

LVDS Interface Pin Name Pin Type Function Pin

LVA0M Output A-Link Negative LVDS Differential Data Output 42 LVA0P Output A-Link Positive LVDS Differential Data Output 41 LVA1M Output A-Link Negative LVDS Differential Data Output 40

TSU16AS

SXGA LCD Controller with Analog Interface and Dual LVDS Transmitter Preliminary Data Sheet Version 0.2

Version 0.2 - 5 - 10/1/2004

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LVA1P Output A-Link Positive LVDS Differential Data Output 39 LVA2M Output A-Link Negative LVDS Differential Data Output 38 LVA2P Output A-Link Positive LVDS Differential Data Output 37 LVA3M Output A-Link Negative LVDS Differential Data Output 34 LVA3P Output A-Link Positive LVDS Differential Data Output 33 LVACKM Output A-Link Negative LVDS Differential Clock Output 36 LVACKP Output A-Link Positive LVDS Differential Clock Output 35 LVB0M Output B-Link Negative LVDS Differential Data Output 52 LVB0P Output B-Link Positive LVDS Differential Data Output 51 LVB1M Output B-Link Negative LVDS Differential Data Output 50 LVB1P Output B-Link Positive LVDS Differential Data Output 49 LVB2M Output B-Link Negative LVDS Differential Data Output 48 LVB2P Output B-Link Positive LVDS Differential Data Output 47 LVB3M Output B-Link Negative LVDS Differential Data Output 44 LVB3P Output B-Link Positive LVDS Differential Data Output 43 LVBCKM Output B-Link Negative LVDS Differential Clock Output 46 LVBCKP Output B-Link Positive LVDS Differential Clock Output 45

GPO Interface Pin Name Pin Type Function Pin

PWM1 Output PWM1; 4mA driving strength 29 PWM0 Output PWM0; 4mA driving strength 28

Misc. Interface Pin Name Pin Type Function Pin

XIN Crystal Oscillator Input Xin 6 XOUT Crystal Oscillator Output Xout 7 VCTRL Output Regulator Control 54

Power Pins Pin Name Pin Type Function Pin

AVDD_ADC 3.3V Power ADC Power 12, 20 VDDP 3.3V Power Digital Output Power 30, 53 DDC 1.8V Power Digital Core Power 32, 55 GND Ground Ground 10, 21, 31, 56

ELECTRICAL SPECIFICATIONS

Analog Interface Characteristics

Parameter Min Typ Max Unit

Resolution 8 Bits DC ACCURACY Differential Nonlinearity ±0.5 +1.50/-1.0 LSB Integral Nonlinearity ±1 LSB No Missing Codes Guaranteed ANALOG INPUT Input Voltage Range Minimum 0.5 V p-p Maximum 1.0 V p-p Input Bias Current 1 uA Input Full-Scale Matching 1.5 %FS Brightness Level Adjustment 62 %FS SWITCHING PERFORMANCE Maximum Conversion Rate 220 MSPS Minimum Conversion Rate 12 MSPS HSYNC Input Frequency 15 200 kHz PLL Clock Rate 12 220 MHz PLL Jitter 500 ps p-p Sampling Phase Tempco TBD ps/ C〣 DIGITAL INPUTS Input Voltage, High (VIH) 2.5 V Input Voltage, Low (VIL) 0.8 V

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Input Current, High (IIH) -1.0 uA Input Current, Low (IIL) 1.0 uA Input Capacitance 5 pF DIGITAL OUTPUTS Output Voltage, High (VOH) VDDP-0.1 V Output Voltage, Low (VOL) 0.1 V DYNAMIC PERFORMANCE Analog Bandwidth, Full Power 250 MHz Channel to Channel Matching 0.5% Full-Scale

Specifications are subjected to change without notice.

TSU16AS

SXGA LCD Controller with Analog Interface and Dual LVDS Transmitter Preliminary Data Sheet Version 0.2

Parameter Symbol Min Typ Max Units

3.3V Supply Voltages VVDD_33 -0.3 3.6 V

1.8V Supply Voltages VVDD_18 -0.3 1.98 V Input Voltage (5V tolerant inputs) VIN5Vtol -0.3 5.0 V Input Voltage (non 5V tolerant inputs) VIN -0.3 VVDD_33 V Ambient Operating Temperature TA 0 70 °C Storage Temperature TSTG -40 150 °C Junction Temperature TJ 150 °C Thermal Resistance (Junction to Air) Natural Conversion θJA TBD °C /W Thermal Resistance (Junction to Case) Natural Conversion θJC TBD °C /W

Note: Stress above those listed under Absolute Maximum Rating may cause permanent damage to those indicated in the stress rating only; functional operation of the device at these or any other conditions outside of those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum ratings foextended periods may affect device reliability.

ORDERING GUIDE Model Temperature Range Package Description Package Option

TSU16AS 0°C to +70°C SDIP

MTV512M64

The MTV512M micro-controller is an 8051 CPU core embedded device especially tailored for flat panel display applications. It includes an 8051 CPU core,768-byte SRAM, 4 channels of 6-bit ADC, 3 external counters/timers, 6 channels of PWMDAC, VESA DDC interface, and a 64K-byte internal program Flash-ROM memory.

FEATURES

• 8051 core, CPU operating frequency up to 24MHz

• 3.3V power supply

• 768-byte RAM; 64K-byte program Flash memory

• Maximum 6 channels of PWM DAC

• Compliant with VESA DDC1/2B/2Bi/2B+/CI standard

• Watchdog timer with programmable interval

• Support external counters/timers, T0, T1, and ET2

• Single/double frequency clock output

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• Two clock output ports

• Two external interrupts, INT1 is shared with Slave IIC interrupt source

• Maximum 4 channels of 6-bit ADC

• Flash-ROM code protection selection

• Hardware ISP (In System Programming), no Boot Code required

• Embedded Dual Ports DDCRAM (128-byte x 2

• Green products like Pb-Free Packages or All Green Packages available

PIN CONFIGURATION & DESCRIPTION

A “CMOS output pin” means it can sink and drive at least 4mA current. It is not recommended to use such pin as input function. An “open drain pin” means it can sink at least 4mA current. It can be used as input or output function and needs an external pull up resistor. An “8051 standard pin” is a pseudo open drain pin. It can sink at least 4mA current when output is at low level, and drives at least 4mA current for 160nS when output transits from low to high, then keeps driving at 120 uA to maintain the pin at high level. It can be used as input or output function. It needs an external pull up resistor when driving heavy load device. There is an internal pull-up resistance on each CMOS PAD and an internal pull-down resistance on each input

Low Power Reset (LVR) & Watchdog Timer

When the voltage level of power supply is below 2.4V (+/-0.4V) for a specific period of time, the LVR generates a chip reset signal. After the power supply is above 2.4V (+/-0.4V)

INVERTER

In order to drive the CCFLs embedded in the panel module, there is a half bridge inverter to convert by the controller. The input 12V up to hundreds of AC voltage output. The inverter is formed by symmetric in order to drive the separate lamp modules. The input stage consists of a PWM controller, half bridge inverter, and switching MOSFET to convert DC input into AC output. The output stage consists of a tuning capacitor, coupling capacitor, transformer, push-pull MOSFET pair to boost AC output up to hundreds of voltage. And one resister is serial to lamp for output voltage feedback. There are two signal to control the inverter which come from system. Logic “high” level which send to I901 is turn on the inverter. BRI signal control brightness by DC level which was integral from PWM signal.

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5. Adjusting Procedure

1. Function Test

1.1. Product

- 19” LCD Monitor

1.2. Test Equipment

- Color Video Signal & Pattern (or PC with SXGA 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) 1280*1024 (H=79.97kHz, V=75Hz)

1.4. Test Display Modes & Pattern

1.4.1 Compatible Modes

Item Timing

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 11 800 x 600 @ 56Hz, 35.1kHz 12 800 x 600 @ 60Hz, 37.9kHz 13 800 x 600 @ 75Hz, 46.9kHz 14 800 x 600 @ 72Hz, 48.1kHz 15 800 x 600 @ 85Hz, 53.7kHz 16 832 x 624 @ 75Hz, 49.7kHz 17 1024 x 768 @ 60Hz, 48.4kHz 18 1024 x 768 @ 70Hz, 56.5kHz 19 1024 x 768 @ 72Hz, 58.1kHz 20 1024 x 768 @ 75Hz, 60.0kHz 21 1024 x 768 @ 85Hz, 68.67kHz 22 1152 x 864 @ 75Hz, 67.5kHz 23 1152 x 870 @ 75Hz, 68.7kHz 24 1280 x 1024 @ 60Hz, 63.4kHz 25 1280 x 1024 @ 75Hz, 79.97kHz 26 1280x 720 @ 60Hz, 45kHz (HDTV)

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1.4.2 Function Test Display Pattern

Item Test Content Pattern Specification Remark

1 Frequency &

Tracking

2 Contrast/Brightness 16 Gray Scale 16 gray levels should be

Fine Line Moire Eliminate visual wavy

noise.

Figure 1

Figure 2

distinguishable.

3 Boundary Horizontal & Vertical

Thickness

Horizontal and Vertical

osition of video should be

Figure 3

adjustable to be within the screen frame.

4 RGB Color

Performance

5 Screen Uniformity &

Flicker

6 Dead Pixel/Line White Screen & Dark

RGB Color Intensities

Contrast of each R, G, B, color should be normal.

Full White Should be compliant with

the spec. The numbers of dead

Screen

pixels should be compliant

Figure 4, 5, 6 Figure 7

Figure 7, 8

with the spec.

7 White Balance White & Black

Pattern

The screen must have the pure white and black

Figure 9

pattern, no other color.

Fine Line Morie Pattern (Figure1) Gray Scale Pattern (Figure2)

Horizontal & Vertical Thickness Pattern (Figure 3) R. Color Pattern (Figure 4)

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