Viewsonic N1900W-1G Service Manual

Service Manual

ViewSonic N1900w-1G

N1900wb-1G

Model No. VS11243-1G

19” LCD TV

(N1900w_N1900wb-1G_SM Rev. 1a Jul. 2006)

ViewSonic® 381 Brea Canyon Road, Walnut, California 91789 USA - [phone]

Copyright

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

ʳ 1a ʳ 07/12/06 ʳʳInitial Release Sophia Kao

ʳʳ ʳ ʳ ʳ

ʳʳ ʳ ʳ ʳ

ʳʳ ʳ ʳ ʳ

ʳʳ ʳ ʳ ʳ

ʳʳ ʳ ʳ ʳ

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TABLE OF CONTENTS

1. Precautions and Safety Notices................................................................. 3

2. Specification............................................................................................... 6

3. Front Panel Function Control Description................................................ 9

4. Circuit Description...................................................................................... 16

5. Adjustment Procedure............................................................................... 21

6. Trouble Shooting Flow Chart..................................................................... 39

7. Block Diagram............................................................................................. 43

8. Schematic Diagrams.................................................................................. 44

9. PCB Layout Diagrams................................................................................ 55

10. Exploded View And Exploded Parts List................................................ 61

11. Recommend Spare Parts List.................................................................. 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 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 Multimedia

TV off.
(6) Do not touch the panel surface with sharp or hard objects.
(7) Do not place heavy objects on the Multimedia TV, 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 Multimedia TV 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. Multimedia TV 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 Multimedia TV.
(11) After installation of the Multimedia TV into an enclosure, do not twist nor bend the

Multimedia TV even momentary. At designing the enclosure, it should be taken into

consideration that no bending/twisting forces are applied to the Multimedia TV from

outside. Otherwise the Multimedia TV may be damaged.
(12) Cold cathode fluorescent lamp in Multimedia TV 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 Multimedia TV.

The Multimedia TV should be supplied by power complied with requirements of

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

Circuit. 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

Parameter Specification

LCD Type TFT Active Matrix Color, TN
LCD Interface TTL
VGA, 640x480 1440x900 pixels
Display Area 410.4 mm (H) x 256.5 mm (V), 19” Diagonal.
Pixel Pitch
Viewing Angle (-75~75)(H), (-70~60)(V)(Typ.) CR>5
Contrast Ratio 500:1 (Typ);350:1 (Min)
Brightness
Response Time Tr+Tf: 8ms(typical) Tr+Tf: 18ms (max)
Color Gamut NTSC 75% Typ
Chromaticity
(CIE1931)
Colors 16.2M (6-bit +FRC)
Surface
Treatment
Backlight 4 CCFLs (Cold cathode Fluorescent Lamp)
Panel
Acceptance

Front Screen
Artifacts

2. Signal Interface

PC Interface
Analog Input Connector DB-15 (Analog)
Default Input Connector Defaults to the PC input
Video Cable Connector DB-15 Pin out Compliant DDC 1/2B.
Video Signals Video RGB (Analog)

Video Impedance 75 Ohms (Analog)
Exclusions Not compatible with interlaced video.

Video Interface

Input Parameter Specification

CVBS Characteristics:
Video Amplitude Signal
DC Level Sync Pulse
S-Video Characteristics:
Video Amplitude Signal
DC Level Sync Pulse

Y, Cb,Cr Characteristics:
Video Amplitude Signal
DC Level Sync Pulse

Video Bandwidth

RF tuner

RF Input Level 0~+15 dB mV

RF Tuning Range

RF Tuner Sensitivity (S/N Ratio at
un-weight)
Channel Bandwidth PAL: 8 MHz Maximum

0.285(H) × 0.285(W)mm

300 cd/㎡(typical)/230 cd/㎡(min)

White-x::0.283,White-y:0.298 (Typ) +/- 0.03

Anti-glare, 3H

Refer to Panel Inspection Section. Multimedia TV Engineering Functional
Specification.
VS Standard:
a.) No Visible Streaking, Sag or Smearing artifacts when driven by the

specified video cards in the primary mode and after user adjustment

b.) No image drift or lose fine-tune settings due to panel temperature change

Separate Sync

0.7(min.)–1.1(max.) V
Typical. 0.35 Vp-p

Y : 1.0Vp-p W / Neg. Sync (IN 75 Ω )
C : 0.285Vp-p (IN 75 Ω )

480i,576i ONLY
Y:1.0Vp-p(IN 75 Ω)
Pb:0.7 Vp-p(IN 75 Ω),Pr:0.7 Vp-p(IN 75 Ω)

PAL :8 MHz Maximum
NTSC 6 MHz Maximum

Parameter Specification

PAL: 48.25 to 855.25 MHz, 2-69 Channels for
Off-Air and 2-125 Channels for CATV

45 dB (min.)

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CVBS Characteristics:
Video Amplitude Signal
DC Level Sync Pulse

0.7(min.)–1.1(max.) V
Typical. 0.35 V
Audio Characteristics:
AF Output Level Measured via LP 20 kHz
Filter, RMS Decoder,
75us De-emphasis
THD
S/N

3. Power

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

4. AUDIO INTERFACE (SPEAKER SPECIFICATION)

Speaker specification

Line inputPC Audio connection 3.5 mm stereo jack
Line input signal 1.0 Vrms
AV,S-Video,YCbCr Audio connection RCA JACK White Left Red Right
Maximum power output (Electric) 2 W@ < 15 % distortion
Signal to Noise Ratio 40 dB
Frequency response 100 Hz – 20 Khz
Distortion < 5 % THD (@1kHz)

Vibration

Screen image

5. Electrical Requirements
Horizontal Frequency 24 – 82 kHz
Vertical Refresh Rate 50 – 85 Hz.
Maximum Pixel Clock 135 MHz
Sync Polarity Independent of sync polarity.

Timing Table

Item Timing

mono
Typical. 0.48V

0.6% (max.)
44 dB (min.)

There should be no audible vibration with volume at
100% and treble / bass at default.
There should be no affect on the screen image
stability under any conditions.

Composite

Digital - TMDS

SOG

Remark

Analog

Separated

1 640 x 350 @ 70 Hz, 31.5 KHz 　 　 　 　

2 640 x 480 @ 60 Hz, 31.5 KHz 　 　 　 　

3 640 x 480 @ 72 Hz, 37.9 KHz 　 　 　 　

4 640 x 480 @ 75 Hz, 37.5 KHz 　 　 　 　
5 720 x 400 @ 70 Hz, 31.5 KHz 　 　 　 　
6 800 x 600 @ 56 Hz, 35.1 KHz

7 800 x 600 @ 60 Hz, 37.9 KHz 　 　 　 　

8 800 x 600 @ 72 Hz, 48.1 KHz 　 　 　 　

9 800 x 600 @ 75 Hz, 46.9 KHz 　 　 　 　

10 832 x 624 @ 75 Hz, 49.7 KHz 　 　 　 　

7

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11 1024 x 768 @ 60 Hz, 48.4 KHz 　 　 　 　

12 1024 x 768 @ 70 Hz, 56.5 KHz 　 　 　 　 576p

13 1024 x 768 @ 75 Hz, 60.2 KHz 　 　 　 　

14 1152 x 864 @ 75 Hz, 67.5 KHz 　 　 　 　

15 1152 x 870 @ 75 Hz, 68.7 KHz 　 　 　 　

16 1280 x 720 @ 60 Hz, 45 KHz 　 　 　 　

17 1280 x 768 @ 60 Hz, 47.8 KHz 　 　 　 　

18 1280 x 768 @ 75 Hz, 60.3 KHz 　 　 　 　

19 1280 x 960 @ 60 Hz, 59.7 KHz 　 　 　 　

20 1280 x 960 @ 75 Hz, 75.2 KHz 　 　 　 　

21 1280 x 1024 @ 60 Hz, 64 KHz 　 　 　 　

22 1280 x 1024 @ 75 Hz, 80 KHz 　 　 　 　

23 1440X900 @ 60 Hz, 55.9 KHz 　 　 　 　

24 1440X900 @ 75 Hz, 75.6 KHz 　 　 　 　

6. Mechanical

Dimension (Desktop)

Width 443mm

Height (Height adjust to the bottom) 381.2mm

Depth 202.5mm

Monitor Weight 5.0Kg

Ergonomics
Tilt Up ≥ 20º

Tilt Down From 0º down to -1º

Swivel Right No

Swivel Left No

7. Environmental

Operating Temperature 0°C to +40°C

Storage Temperature -20°C to +60°C

Operating Relative Humidity 20% 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

Front View of the Product

1 2 3 4 5

6

87

1

3

2

4

5

6

7

8

Volume Down

Decrease sound volume or adjust a highlighted control while in OSD menu.

Volume Up

Increase sound volume or adjust a highlighted control while in OSD menu.

MENU

T

urn OSD menu ON/OFF.

CH Down

Channel down when source is at

TV or select a control while in OSD menu.

CH Up

Channel up when source is at

TV or select a control while in OSD menu.

ENTER

T

o highlight a control in OSD menu.

Power button
Remote control receiver / Power LED indicator

Note:

1. Press VOL+ and MENU buttons at the same time to lock power button, and press
VOL+ and MENU buttons again to unlock it.

2. Press VOL- and VOL+ buttons at the same time to lock OSD menu, and press
VOL- and VOL+ buttons again to unlock it.

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Rear View of the Product

D

A

B

C

F

G

E

H

Power Input (AC Input)

Using power cord provided, connect to a power source.

PC Audio input

Connect this port to PC line out jack.

AV/ S-Video/ YCbCr signal Audio input (left/right)

Connect this port to the RCA audio output connectors of your A/V device.

TV signal input

Connect to the antenna or cable service.

VGA signal input

Connect this port to the VGA output of your PC.

S-Video input

Connect this port to the S-Video output of A/V device.

YCbCr input

Connect this port to the YCbCr output of A/V device.

Composite Video input

Connect this port to the RCA output connectors of your A/V device.

F

E

C

D

B

H

G

A

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Remote Control

A
B
C
D
E
F

G
H

I

J
K
L

INPUT button
TV button
VOL

+ and VOL – button
0~9 number button
POWER button
UP/DOWN/ LEFT/RIGHT/

ENTER button
MENU button
CH ▲ and CH ▼ button
MUTE button
INFO button
SLEEP

button

RETURN button

Input source select
Direct to

TV mode
Adjust volume UP/DOWN
Directly channel select
Power ON/OFF
U

P/DOWN/LEFT/RIGHT: Navigate and adjust OSD function

ENTER: Enter the function setting
On Screen Display (OSD) menu ON/OFF
Adjust Channel UP/DOWN
V

olume mute ON/OFF
Display current information
Set

TV sleep timer

Return to previous channel

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OSD Functions

Picture Menu

1. You can use this menu to adjust the following settings.

2. Press ▲▼ to highlight the desired option, press ENTER to enter, and press ◄ ► to adjust.

3. Press MENU repeatedly to exit.

When input source is PC:

Brightness: To adjust the luminance of the picture.
Contrast: To adjust the contrast ratio of the picture.
Color Temp: To select the color temperature between Warm, Normal, Cold and User. When

selecting User, you can adjust the level of Red, Blue and Green colors by press
then Using ◄ ►.

Phase: To adjust picture phase to reduce horizontal-line noise.
Clock: To adjust picture clock to reduce vertical-line noise.
H-Position: To center the image by moving it left or right.
V-Position: To center the image by moving it up or down.
Color: To adjust the color saturation.
Sharpness: To adjust picture sharpness.
Aspect: To select image size for 16:10 or 4:3.

When input source is AV, S-Video, YCbCr or TV:

ENTER and

ENGLISH

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ENGLISH

Audio Menu

1. You can use this menu to adjust the following settings.

2. Press ▲▼ to highlight the desired option, press ENTER to enter, and press ◄ ► to adjust.

3. Press MENU repeatedly to exit.

When input source is PC, AV, S-Video, YCbCr or TV:

Volume: To adjust the volume.
Mute: To mute the sound. Press ENTER and then use ▲▼ or ◄ ► to switch between On and Off.

Options Menu

1. You can use this menu to adjust the following settings.

2. Press ▲▼ to highlight the desired option, press ENTER to enter, and press ◄ ► to adjust.

3. Press MENU repeatedly to exit.

When input source is AV, S-Video, YCbCr:When input source is PC:

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When input source is TV:

Input Select: To select input source between PC, AV, S-Video, YCbCr, and TV.
Auto Adjust: To auto adjust picture’s horizontal position, vertical position, fine tune, and
H-Size. Press ENTER to auto adjust.
Reset: To reset all the settings in Picture, Audio and Options pages.
Information: To show displaying mode condition. Press ENTER to show the current resolutions.
Sharpness: To adjust picture sharpness
Sleep: To adjust the off timer up to 120 minutes.
No Signal Auto Off: To automatically shut the TV off if there is no signal being played or

received for a period of time.
Channel Settings: To adjust channel settings. (Only available when the input source is TV.)
Press ENTER and the following screen will show.
Press ENTER again, and a “Yes” will appear on the highlighted cursor bar.

ENGLISH

Press ENTER to confirm your selection, and the Auto Search starts.

Press Menu at anytime to interrupt searching.

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ENGLISH

Scan PAL DK: Press ENTER twice to auto scan channels. (suitable for use in China)
Scan PAL I:
Scan SECAM: Press ENTER twice to auto scan channels. (suitable for use in Russia)
Channel: To select your desired channel by entering channel number or using ▲▼◄ ►.
Frequence: To display the frequency of the channel selected. Press ENTER, and the
optional item of “Fine Tuning” will appear.

Fine Tuning: To adjust the frequency of channels in order to reduce the noise in picture.

Press ◄ ► to adjust manually.

Press ENTER twice to auto scan channels. (suitable for use in Hong Kong)

Settings Menu

1. You can use this menu to adjust the following settings.

2. Press ▲▼ to highlight the desired option, press ENTER to enter, and press ◄ ► to adjust.

3. Press MENU repeatedly to exit.

When input source is PC, AV, S-Video, YCbCr or TV:

Language: To select the language of OSD.
OSD H. Pos: To adjust the horizontal position of OSD.
OSD V. Pos: To adjust the vertical position of OSD.
OSD Time-out: To set the display duration of OSD.
Reset Settings: To reset all the settings in Settings page.

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4. Circuit Description

I106 TSU16AVJ-1

The TSU16AVJ-1 is total solution graphics processing IC for LCD monitors with panel resolutions up
to WXGA+/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 TSU16AVJ-1 also integrates intelligent power management control
capability for green-mode requirements and spread-spectrum support for EMI management.
The TSU16AVJ-1 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 TSU16AVJ-1 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.

PIN DESCRIPTION

CPU Interface

Pin Name Pin Type Function Pin

HWRESET Schmitt Trigger Input
w/ 5V-tolerant
Hardware reset; active high 121
CS Input w/ 5V-tolerant 3 Wire Serial Bus Chip Select; active high 40
SDA I/O w/ 5V-tolerant 3 Wire Serial Bus Data; 4mA driving strength 41
SCL Input w/ 5V-tolerant 3 Wire Serial Bus Clock 42
INT Output CPU interrupt; 4mA driving strength 43

Analog Interface

Pin Name Pin Type Function Pin

HSYNC0 Schmitt Trigger Input
w/ 5V-tolerant
Analog HSYNC Input 126
VSYNC0 Schmitt Trigger Input
w/ 5V-tolerant
Analog VSYNC Input 127
RMID Mid-Scale Voltage Bypass 36
REFP Internal ADC Top De-coupling Pin 37
REFM Internal ADC Bottom De-coupling Pin 38
RIN0P Analog Input Analog Red Input 33
RIN0M Analog Input Reference Ground for Analog Red Input 32
SOGIN0 Analog Input Sync-On-Green Input 31
GIN0P Analog Input Analog Green Input 30
GIN0M Analog Input Reference Ground for Analog Green Input 29
BIN0P Analog Input Analog Blue Input 28
BIN0M Analog Input Reference Ground for Analog Blue Input 27
REXT External resistor 390 ohm to AVDD_ADC 15

Video Interface

Pin Name Pin Type Function Pin

VCLK Input w/ 5V-tolerant Video Decoder Clock 46
VD[7:0] Input w/ 5V-tolerant Video Decoder Data[7:0] 54-47

LVDS Interface

Pin Name Pin Type Function Pin

LVA0M Output LVDS A-Link Channel 0 Negative Data Output 81
LVA0P Output LVDS A-Link Channel 0 Positive Data Output 80
LVA1M Output LVDS A-Link Channel 1 Negative Data Output 79
LVA1P Output LVDS A-Link Channel 1 Positive Data Output 78
LVA2M Output LVDS A-Link Channel 2 Negative Data Output 77
LVA2P Output LVDS A-Link Channel 2 Positive Data Output 76
LVA3M Output LVDS A-Link Channel 3 Negative Data Output 71
LVA3P Output LVDS A-Link Channel 3 Positive Data Output 70
LVACKM Output LVDS A-Link Negative Clock Output 75

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LVACKP Output LVDS A-Link Positive Clock Output 74
LVB0M Output LVDS B-Link Channel 0 Negative Data Output 97
LVB0P Output LVDS B-Link Channel 0 Positive Data Output 96
LVB1M Output LVDS B-Link Channel 1 Negative Data Output 93
LVB1P Output LVDS B-Link Channel 1 Positive Data Output 92
LVB2M Output LVDS B-Link Channel 2 Negative Data Output 91
LVB2P Output LVDS B-Link Channel 2 Positive Data Output 90
LVB3M Output LVDS B-Link Channel 3 Negative Data Output 87
LVB3P Output LVDS B-Link Channel 3 Positive Data Output 86
LVBCKM Output LVDS B-Link Negative Clock Output 89
LVBCKP Output LVDS B-Link Positive Clock Output 88

GPO Interface

Pin Name Pin Type Function Pin

PWM1 Output PWM1; 4mA driving strength 45
PWM0 Output PWM0; 4mA driving strength 44

Misc. Interface

Pin Name Pin Type Function Pin

BYPASS For External Bypass Capacitor 103
DDC_DAT I/O w/ 5V-tolerant DDC Data for Analog Interface; 4mA driving strength 117
DDC_CLK Input w/ 5V-Tolerant DDC Clock for Analog Interface 118
DDCROM_CLK Input w/ 5V-Tolerant DDC ROM Clock 119
DDCROM_DAT I/O w/ 5V-tolerant DDC ROM Data; 4mA driving strength 120
XIN Crystal Oscillator Input Xin 122
XOUT Crystal Oscillator Output Xout 123

Pin Name Pin Type Function Pin

AVDD_ADC 3.3V Power ADC Power 8, 14, 18, 35
AVDD_PLL 3.3V Power PLL Power 16
AVDD_MPLL 3.3V Power MPLL Power 124
VDDP 3.3V Power Digital Output Power 55, 61, 72, 82, 94,
107, 114
VDDC 1.8V Power Digital Core Power 58, 64, 85, 111
GND Ground Ground 2, 5, 11, 17, 19, 34,
39, 56, 57, 62, 63,
66, 69, 73, 83, 84,
95, 101, 102, 106,
112, 113, 125

No Connects

Pin Name Pin Type Function Pin

NC No Connect. Leave These Pins Floating. 1, 3, 4, 6, 7, 9, 10,
12, 13, 20-26, 59,
60, 65, 67, 68,
98-100, 104, 105,
108-110, 115, 116,
128

Absolute Maximum Ratings

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 34 °C/W
Thermal Resistance (Junction to Case) Natural
Conversion
θJC 6.0 °C/W
TSU16AVJ-1 0 C to +70 C PQFP 128

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I107TW9906

TW9906 – NTSC/PAL/SECAM Analog to Digital Video
Decoder with Analog YPbPr Component Input
Techwell’s TW9906 is a high quality NTSC/PAL/SECAM video decoder that is designed for
multimedia applications. It uses the mixed-signal 2.5V/3.3V CMOS technology to provide a lowpower
integrated solution.
The TW9906 analog front-end is equipped with three separate analog channels that enable it to
accept all three possible analog video signal standards: composite, S-video or YPbPr component
video. All channels include an analog multiplexer (MUX) for maximum flexibility in software
The TW9906 supports flexible pixel interface. It outputs YCbCr (4:2:2) data stream over 10-bit or
20-bit data path. The output is VMI 1.4 compatible.
A 2-wire serial MPU interface is used to simplify system integration. All the functions can be
controlled through this interface.
Analog Front-end
The analog front-end converts analog video signals to the required digital format. There are three
analog channels with clamping circuits and ADCs. The Y channel has 5-input multiplexer, and a
variable gain amplifier for automatic gain control (AGC). Its four inputs are identified as MUX0,
MUX1, MUX2, MUX3 and MUX4(share the same pin with VIN1). The C channel has a 2-input
multiplexer. Its two inputs are identified as CIN0 and CIN1. The V channel is similar to C channel.
Its input is VIN0 and VIN1. Both the C and V channel are internally clamped to the zero level of the
bipolar input source when enabled.
Video Source Selection
All analog signals should be AC-coupled to these inputs. The Y channel analog multiplexer selects
one of the four inputs MUX[0-4]. MUX[0-4] can be connected to composite video inputs or the Y
signal of an S-Video or component input. When decoding a S-Video input, the Y signal should
connect to one of the MUX inputs and the C signal to CIN0 or CIN1.
When decoding a component input, in addition to the Y signal, the C signal should connect to CIN0
or CIN1, and V signals should be connect to VIN0 or VIN1 pins.
Sync Processing
The sync processor of TW9906 detects horizontal synchronization and vertical synchronization
signals in the composite video or in the Y signal of an S-video or component signal. The processor
contains a digital phase-locked-loop and decision logic to achieve reliable sync detection in stable
signal as well as in unstable signals such as those from VCR fast forward or backward.
Horizontal sync processing
The horizontal synchronization processing contains a sync separator, a phase-locked-loop (PLL),
and the related decision logic.
The horizontal sync detector detects the presence of a horizontal sync tip by examining low-pass
filtered input samples whose level is lower than a threshold. After sufficient low levels are detected,
a horizontal sync is recognized. Additional logic is also used to avoid false detection on glitches.
The horizontal PLL locks onto the extracted horizontal sync in all conditions to provide jitter free
image output. From there, the PLL also provides orthogonal sampling raster for the down stream
processor. The PLL has free running frequency that matches the standard raster frequency. It also
has wide lock-in range for tracking any non-standard video signal.
Vertical sync processing
The vertical sync separator detects the vertical synchronization pattern in the input video signals.
In addition, the actual sync determination is controlled by a detection window to provide more
reliable synchronization. It achieves the functionality of a PLL without the complexity of a PLL

I108 MTV416M

8051 Embedded Micro-Controller with 128K Flash
The MTV416M micro-controller is an 8051 CPU core embedded device targeted for LCD Monitor or
LCD TV application. It includes an 8051 CPU core, a 128K-byte internal program Flash-ROM, a
768-byte SRAM, 4 channels of PWM DAC, 4 channels of 6-bit ADC, and a built-in sync-processor. It
also includes two IIC Slave B ports, supporting VESA DDC/CI for both D-sub and DVI interfaces, and
a Boot-Code-Free ISP (In System Programming).

　8051 core, up to 24MHz operating frequency
　+ 3.3V power supply
　768-bytes RAM; 128K-byte program Flash-ROM

- 256 bytes Internal RAM

- 256 bytes Auxiliary RAM

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- 128 x 2 bytes DDC RAM

　4 channels of PWM DAC

- Sink current up to 10 mA (DA0 ~ DA3)

- Programmable PWM output frequency (100 Hz~ 100KHz)

- 14-bit PWM out for VCT application (DA2 and DA3)

　Maximum 39 I/O pins
　Maximum 10 channels of +3.3V/+5.0V tolerant I/O

- Hsync, Vsync, HSCL1, HSDA1, HSCL2,HSDA2, and General I/O x 4

　SYNC processor for composite separation /insertion, H/V polarity/frequency check and polarity

adjustment

- Programmable hysteretic window for built-in Schmitt Trigger

　Built-in analog filter for Hsync, Vsync, and IIC input pins
　Support SOG (Sync On Green) input
　Two clock output ports to drive other devices

- Programmable output driving current for EMI repression (CLKO1)

　Built-in dual DDC RAMs, H/W auto transfer

DDC1/DDC2x data for both D-sub and DVI interfaces

　Built-in two IIC Slave B ports, supporting VESA

DDC1/2B/2Bi/2B+/CI standards

　Single master IIC interface for peripheral device communication
　Maximum 4-channel 6-bit A/D converter with Flag indication

- Conversion time: 16 uS

- Input voltage level: 0 ~ +VDD

　ISP (In System Programming)

- Support H/W ISP, no Boot Code required

　Programmable Watch Dog Timer
　Flash-ROM program code protection

　48-pin LQFP packages

　Green packages available
　Main application fields: LCD Monitor, LCD TV

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.

AUDIO

I601

The TDA8944AJ is a dual-channel audio power amplifier with DC gain control. It has
an output power of 2W at an4 load and a 12 V supply. The circuit contains two　
Bridge-Tied Load (BTL) amplifiers with an all-NPN output stage and standby/mute
logic. The overall gain can be adjusted from +30 dB down to 50 dB using a DC
control voltage. This feature can be used for volume control or a preset gain.
The TDA8944AJ comes in a 17-pin DIL-bent-SIL (DBS) power package and is pin
compatible with the TDA8944J.

Symbol Pin Description

OUT11 negative loudspeaker terminal 1
GND1 2 ground channel 1
VCC1 3 supply voltage channel 1
OUT14 positive loudspeaker terminal 1
n.c. 5 not connected

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IN16 positive input 1
SGND 7 signal ground
IN18 negative input 1
IN29 negative input 2
MODE 10 mode selection input (standby, mute, operating)
SVR 11 half supply voltage decoupling (ripple rejection)
IN212 positive input 2
GC 13 DC gain control
OUT214 negative loudspeaker terminal 2
GND2 15 ground channel 2
VCC2 16 supply voltage channel 2
OUT217 positive loudspeaker terminal 2

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5. Adjusting Procedure

1. ADJUSTMENT CONDITIONS AND PRECAUTIONS

1. Approximately 30 minutes should be allowed for warm up before proceeding.

2. Adjustments should be undertaken only on those necessary elements since most of them
have been carefully preset at the factory.

3. ESD protection is needed before adjustment.

2. MAIN ADJUSTMENTS

NO. FUNCTION DESIGNATION

1. PC AUTO COLOR Function Key

2. Adjust color temperature Function Key

3. ALIGNMENT PROCEDURES

Adjustment Conditions and Precautions:

(A). Power supply voltage:
AC 220/240V± 10% 50 Hz ± 5%.
(B). Warm up time:
The display must be power ON for at least 30 minutes at full white pattern before
starting alignments.
This is especially critical in color temperature and white balance adjustments.
(C). Video : reference the front detail specifications.

I. PC AUTO COLOR:

(A). Power OFF then Press “ENTER” and “POWER” key
go to factory mode.

B). Move the color bar to AUTO BURN , then press “ ENTER” key to inter BURIN MODE.
Set at PC Souce timing set at 1440x900 60HZ
Use Chroma 2327 pattern Generator PATTEN use 5 block
Move the color bar to AUTO COLOR , then press “ ENTER” key to do AUTO COLOR

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II. Adjust color temperature ( for TV, AV, S-Video ):

(A). Use TV Signal Generator
(B). Pattern: Full White
(C). Normal (9300K) Verify:
Use “▼”, “▲” key to move color bar up or down, press “ Vol –” , “ Vol+” key
adjust R.G.B GAIN Value.

X=0.283±0.03
Y=0.298±0.03
Y=380(min) ~ 450 cd/m2 (Typ)

move color bar to Warm (6500K)
X=0.313±0.03
Y=0.329±0.03

move color bar to Cold (12000K)

X=0.271±0.03
Y=0.278±0.03

III.Adjust color temperature(for YPbPr)

(A). Chroma 2327 pattern Generator.
(B). Pattern: Full White(pattern No.42)
(C). Normal (9300K) Verify:
Use “▼”, “▲” key to move color bar up or down, press “ Vol –” , “ Vol+” key
adjust R.G.B GAIN Value.

X=0.283±0.03
Y=0.298±0.03
Y=380(min) ~ 450 cd/m2 (Typ)

move color bar Warm (6500K)

X=0.313±0.03
Y=0.329±0.03

move color bar Cold (12000K)

X=0.271±0.03
Y=0.278±0.03

press “ MENU” key exit
press “ POWER” key quit factory mode

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4. Firmware Upgrade Procedure

When you receive the returned monitor, please check whether the firmware version is the latest.

If not, please do the following procedures to upgrade it to the latest version.

4.1 Equipment Needed

-- Fixture for Firmware Upgrade

-- PC (Personal Computer)

-- LPT Cable

-- Firmware Upgrade Program

-- One additional monitor for checking the program execution

Printer Port

PC

LPT Cable

N1900W1G

VGA CABLE (MALE)

4.2 Setup Procedure

4.2.1 Connect P2 of Fixture with printer port of PC by LPT Cable.

4.2.2 Connect Power Cord to Monitor.

4.2.3 Connect PC to the additional monitor.

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ISP Download program procedure

1. Hardware Connect status

2. Down load isp program

Step 1: Execute ISP.exe

Select MTV416M128
Step 2: Set ISP mode

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puch Create Security File
set Command No 4

ISP Slave Add 94

Slave B Add 94
Command 1 ac
Command2 ca
Command 3 53
Puch ok
Select Load file

Load Mcu File
Puch Read OK
Step 3: Run and finish

Puch RUN
Puch Reset MCU

Trouble shooting:

If you find the status like the follow picture. Please check the following item.
a. The connecting status between PC and ISP board.
b. The connecting status between ISP status and Monitor.

Turn off the power of monitor (AC plug off ) and disconnect the D-Sub connector . To connect the
D-Sub connector and then turn on the power of monitor.(AC plug on)

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