AOC L22W851B User manual

22’’ LCD TV AOC L22W851B
1
Service
Service
Service
Horizontal Frequency
40 kHz to 61.25 kHz
TABLE OF CONTENTS
Description Page Description Page
SAFETY NOTICE
ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE HIMSELF WITH THE
CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS TO BE USED WHEN SERVICING
ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.
CAUTION: USE A SEPARATE ISOLATION TRANSFOMER FOR THIS UNIT WHEN SERVICING
Table Of Contents.......……..............................…........1
Important Safety Notice.......................................……......2
Revision List.…........................................……...... 3
1. General Specification..............................………........4
2. Operating Instructions…………………….……….......5
2.1. The Use Of Remote Control…….………….…….......5
2.2. To Use The Menu…...…………………….……….......7
2.3. How To Connect…….…………………….……….....11
2.4. Front Panel Control Knobs……………….……….....14
3. Input/Output Specification…………....................…....15
4. Mechanical Instructions…………………….................17
5. Repair Flow Chart ……………………….…….…….....22
6. PCB Layout ………………..………………....….......28
6.1.Ma in Boar d …………..………….……….......28
6.2.Power Board……………..………….……….......30
6.3.Tuner Board……………………..………..............32
6.4. IR Board………………………………..……….......33
6.4. Key Board……………………………..……….......33
7. White-Balance, Luminance Adjustment...................34
8. Block Diagram.……...........................................36
9. Schematic……………...…………..………………...37
9.1 Main Board…….…………..……………….….......37
9.2.Power Board…………….……….………….......49
9.3.Tuner Board……………………..………..............51
9.4.IR Board……………………..………..............55
9.5.Key Board……………………..………..............56
10. Exploded View..……………............................…..57
11. BOM List……………….………………………….….58
12. Different Parts List……………………………….….79

22’’ LCD TV AOC L22W851B
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Important Safety Notice
Proper service and repair is important to the safe, reliable operation of all AOC Company Equipment. The service
procedures recommended by AOC and described in this service manual are effective methods of performing service
operations. Some of these service operations require the use of tools specially designed for the purpose. The
special tools should be used when and as recommended.
It is important to note that this manual contains various CAUTIONS and NOTICES which should be carefully read in
order to minimize the risk of personal injury to service personnel. The possibility exists that improper service
methods may damage the equipment. It is also important to understand that these CAUTIONS and NOTICES ARE
NOT EXHAUSTIVE. AOC could not possibly know, evaluate and advise the service trade of all conceivable ways in
which service might be done or of the possible hazardous consequences of each way. Consequently, AOC has not
undertaken any such broad evaluation. Accordingly, a servicer who uses a service procedure or tool which is not
recommended by AOC must first satisfy himself thoroughly that neither his safety nor the safe operation of the
equipment will be jeopardized by the service method selected.
Hereafter throughout this manual, AOC Company will be referred to as AOC.
WARNING
Use of substitute replacement parts, which do not have the same, specified safety characteristics might create
shock, fire, or other hazards.
Under no circumstances should the original design be modified or altered without written permission from AOC.
AOC assumes no liability, express or implied, arising out of any unauthorized modification of design.
Servicer assumes all liability.
FOR PRODUCTS CONTAINING LASER:
DANGER-Invisible laser radiations when open AVOID DIRECT EXPOSURE TO BEAM.
CAUTION-Use of controls or adjustments or performance of procedures other than those specified herein may
result in hazardous radiation exposure.
CAUTION -The use of optical instruments with this product will increase eye hazard.
TO ENSURE THE CONTINUED RELIABILITY OF THIS PRODUCT, USE ONLY ORIGINAL MANUFACTURER'S
REPLACEMENT PARTS, WHICH ARE LISTED WITH THEIR PART NUMBERS IN THE PARTS LIST SECTION OF
THIS SERVICE MANUAL.
Take care during handling the LCD module with backlight unit
-Must mount the module using mounting holes arranged in four corners.
-Do not press on the panel, edge of the frame strongly or electric shock as this will result in damage to the screen.
-Do not scratch or press on the panel with any sharp objects, such as pencil or pen as this may result in damage to
the panel.
-Protect the module from the ESD as it may damage the electronic circuit (C-MOS).
-Make certain that treatment person’s body is grounded through wristband.
-Do not leave the module in high temperature and in areas of high humidity for a long time.
-Avoid contact with water as it may a short circuit within the module.
-If the surface of panel becomes dirty, please wipe it off with a soft material. (Cleaning with a dirty or rough cloth may
damage the panel.)

22’’ LCD TV AOC L22W851B
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Revision List
Version
Release Date
Revision Instructions
TPV Model
A00
Aug.-29-07
Initial Release
E227ANNB2WA1NN
A01
Sep.-17-07
Add new model
E227ANNB2WA3NN
E227ANNL2WMKNN
A02
Nov.-20-07
Add new model
E227MNNB2WA1NN
A03
Jan.-04-2008
Add new model
E227MNNB2WAC2N

22’’ LCD TV AOC L22W851B
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1. General Specification
Items
Specification
LCD Panel
Screen Size
22” TFT-LCD Panel
Contrast Ratio
500:1
Resolution
1680 x 1050 pixels
Viewable image size:
558mm diagonal
TV
Function
TV Tuning System
Analog
PAL/SECAM
Sound System
Analog
Nicam / A2
Teletext
Yes (10 Pages)
Color systems
PAL / SECAM
Video
Inputs
SCART
(RGB+CVBS) x1
AV1
RCA(Composite) x 1
Audio L/R x 1
(Share)
S-Video
S-Video x 1
Component
Video input: D-Sub 15 pins
Audio input:Used as a stereo earphone mini
jack (3.5 ø)
HDMI
HDMI x 1
PC mode
Signal input
Analog: D-Sub 15 pins (separate)
Plug and play compatible
DDC 2B
Recommended
Analog: 1680x1050 (60Hz)
Audio input
Used as a stereo earphone mini jack (3.5 ø)
Audio Output
Audio output: L/R
Speaker (built-in):2*5 watt speakers
Headphone: Mini-jack for stereo (3.5ø)
OSD language
English/France/Germany/Spanish/Danish/Russian/Italy/
Finland/Sweden/Poland
Power
Power supply
AC100V~240V, 50/60Hz
Power Consumption
Power-on<75W;
Power saving-off<3W
Dimension
W x H x D (with stand)
539mmx447mmx209mm
Weight
KG(W/O Accessories)
6.2kg/8.6kg
Accessories
Remote control with batteries(AAX2),AC power cord, VGA to Component cable(x1), PC Audio
to RL cable(x1) , User’s Guide, QSG

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2. Operating Instructions
2.1 The Use of Remote Control
Use of the remote control
POWER:
Press to turn on/off the
TV.
The TV is never
completely powered off
unless it is physically
unplugged.
CH
Press + or - (or MENU
/button) buttons to
scroll through the
channels.
VOL
Press + or –to increase
or decrease the volume.
PC
Select your input source
to PC.
SLEEP
With this key you can set
a time period after which
the TV should switch
itself to standby. Press
the key repeatedly to
select the number of
minutes. The counter
runs from 0~120
minutes. The timer
begins to count down
from the number of
minutes selected after
the display has
disappeared.
SWAP
SWAP is not available on
this model.
MENU
Press this key to display
or exit main menu.
Size
Size is not available
on this model.
DISPLAY
Press this key to display:
(1) the channel number when
watching a TV program.
(2) the input source when
watching the other video
program.
MUTE
Temporarily interrupt the
sound or restore it.
SUBPAGE
In the Teletext mode, this is
subpage function.In theTV
mode,Press subpage to
select 1** channel
0~9 DIGIT BUTTONS
To select a TV channel.
PRE-CH
To display the previously
selected TV channel.
TV/VIDEO
Select your input source:
press repeatedly to select
TV, AV, S-VIDEO or SCART
HDMI mode, according to
where you connected your
external source.
SOUND
To select Mono/ Stereo/Dual
from TV RF input.
PIP/POP
PIP/POP is not available on
this model.

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TELETEXT
Teletext is an information service organized like a magazine, which is provided by some TV stations in addition to
regular television broadcasting.
TELETEXT
Press TELETEXT. The Teletext screen appears.
To turn off the Teletext mode, press TELETEXT
again.
MIX
Press MIX to superimpose the teletext over a
normal broadcast picture. Press again to return
to Teletext mode.
SIZE
Press SIZE repeatedly to display the upper
teletext part, the lower teletext part and then to
return to the normal.
RED / GREEN / YELLOW / BLUE
Use the COLOURED BUTTONS to operate
the Teletext screen.
INDEX
Press INDEX to return to the main index page.
SUBTITLE
Press to select the next page marked as a subtitle
page and request it as the display page.
HOLD
Press HOLD to hold the Teletext page when
viewing information. Press again to return to
automatic page update.
REVEAL
Press REVEAL to display reveal hidden words e.g.
quiz page answers. Press again to hide.
PAGE SELECTION
Page can be selected in two ways.
a. Press ▼or ▲to increase or decrease the page number by one.
b. By entering the page number, using digit buttons 0~9.

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2.2 To Use the Menus
1. Press the MENU button to display or close main menu.
2. Use the cursor up/down to select a menu item.
3. Use the cursor left/right to enter a submenu or enable/disable the
function.
4. Press the MENU button to exit the menu.
Main Menu
Press the MENU button to enter the main OSD (On Screen Display). Adjust the items including Picture Setup,
Sound setup, Function Setup and TV setup. When the input source is AV/S-VIDEO /SCART/ PC/ HDMI mode,
only the Sound Setup, Picture Setup and Function Setup can be selected; shown in the figure below:
When the input source is TV mode, the Sound Setup, Picture Setup, Channel select Setup, Function Setup and TV
Setup can be selected; shown in the figure below:
Sound Setup (Same as in TV/AV/S-VIDEO /SCART/ PC/ HDMI)
1. The range of adjusting volume, bass and treble is from 0~100.
2. Bass and Treble:the easy Equalizer function,Bass can adjust the low frequency sound and Treble can adjust the
high frequency sound.
3. The range of adjusting Balance is -50~+50; when adjusting from 0 to -50, the sound from the left track fades
until silence; when adjusting from 0 to +50, the sound from the right track fades until silence.
4. AVL: you can set it “ON” or “OFF”.
The function is to adjust the input sound automatically. You may enable this function when you notice that the
sound in the two tracks are very different, in order to prevent the bad sound effect resulting from large sound

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variation.
5. Select "ON" or "OFF" for Loudness: a default setting is preset, you may adjust when necessary.
The following menu will appear when selecting continuously:
6. Preset: Designed for different types of sound output, where in, the voice music ,personal and theatre modes are
preset; you can set Bass, Treble and Equalizer in sound output mode according to your preference.
7. Equalizer: You can select and adjust 100, 300, 1K, 3K and 8K respectively (the figures represent the sound
frequency range).
8. Reset to default: Reset the sound setting to the factory default value.
Picture Setting
When the input source is in TV/AV/S-VIDEO /SCART/ HDMI, you can select Brightness, Contrast, Colour,
Sharpness, Dyn. Colour Temp, reset and Reset to default respectively; shown in the figure below:
When the input source is in PC mode, you can select Brightness, Contrast, Position, Video noise, Sharpness, Auto
Adjust, Info, Colour Temp., Red, Green, Blue and Reset to default.

22’’ LCD TV AOC L22W851B
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1. Brightness and Contrast: The range can be adjusted from 0~100.
2. Position: There are two options, Horizontal and Vertical, which can be adjusted from -50 to +50.
3. Video noise: There are two options, Phase and Clock, which can be adjusted from -50 to +50.
4. Sharpness: Select from five options of Softest, Soft, Auto, Sharp and Sharpest. You may adjust the above
options according to your preference.
5. Auto Adjust: Automatically adjust PC input to the optimal screen size.
6. INFORMATION: Prompt the current size for PC input definition (only the definition that can be shown by this
device).
7. Colour Temp.: There are four options of colour temperature provided for users - normal, warm, cold and User.
You can select the three colour temperatures of normal, warm, and cold, or manually adjust red, green or blue in
the User setting (you can only adjust red, green and blue in the user setting).
8. Reset to default: It is used to reset the picture settings to the factory default mode.
Function Setup
When the input source is in TV mode, you can select Source OSD, Language, Country, ACI, Timers, TT Language,
Teletext E/W and Reset to default; shown in the figure below:
1. Current Source OSD setting: When OSD is set to ON, the left upper corner of the display will show the input
source or the TV channel number; when OSD is set to OFF, the input source or the TV channel number will
disappear.
2. OSD language setting: There are ten language options provided - English, France, Deutsch, Spanish,
Portuguese, Poland, Russian, Italian, Finnish, Swedish.
3. Country and ACI function：the user can select Country and if the program system has ACI （Auto Channel
Installation）function.
4. Timers
(1).Sleep Timer:preset a time so that the set can get into standby mode after that time . And the alert function
will count down when there is one minute left.
(2). Reminder timer: set an alert time so that when the time finished, there will be a warning to remind the user.
5. TT Language. and Teletext E/W：the user can set the teletext language.
6. Reset: It is used to reset the OSD settings.
When the input source is in AV, S-Video or SCART mode, you can select Source OSD, Language, Timers, TT
Language., Teletext E/W and Reset to default;
When the input source is in PC and HDMI mode, you can select Source OSD, Language, Timers and Reset to
default;

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TV Setting
The following menu appears only in the TV mode.
A.channel select function
This set can give the user a channel list that all channel received
B.channel setup function
1. Program nr: Shows the current program number.
2. Program name：show the program name,also the user can give the program a unique name
3. Colour System / sound system: select the colour and sound system the current channel.you can selet ”auto”,the
set will identify it by oneself
4. Auto search: Select "Auto Search" to search all signaled channel; when the searching is complete, it stays at the
first channel with signal and all channels that have been located are stored. If you would like to stop "Auto
Search" during the process, simply by pressing the function button.
5. Frequency：show the current signal Frequency
6. AFC can be set to ON or OFF. When it is set to ON, the TV will search the TV signal automatically; when there is
any offset in the signal, it will automatically adjust the channel to the correct position.
7. Skip can be set to ON or OFF. When it is set to ON, a channel can be skipped by pressing the CH button on the
remote control or on the front panel.
8. Reset to default: Reset to the factory default value.

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2.3 How to Connect
Lay the LCD TV with the screen down on a table, as it will be easier to connect your peripheral equipment. Please
take your precautions not to damage the screen.
1: AV1 signal input
2: Right audio track input
3: Headphone outlet
4: TV signal input
5: SCART signal input
6: Left audio track input
7: S-Video signal input
8: VGA input
9: HDMI input
10: VGA audio input
11: AC power input terminal

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1> PC input:
Note: For the connection between the PC and the TV, (see Figure 1) below.
(Figure 1)
(1)How to connect to the PC mainframe:
VGA interface –Connect the VGA signal cable supplied with the TV to the D-sub interface at the rear of the TV as
in. (Figure 1)
(2)How to connect the audio cable:
Connect the PC audio cable supplied with the TV to the TV’s PC Audio Input as in. (Figure 1)
Note: If no signal is present on the VGA screen, the TV will enter into standby mode automatically after 3
seconds.
2> HDMI input:
HDMI is the leading new standard for Digital video and audio interconnection. To the HDMI connector you can
connect HDMI devices such as a Set Top Box or compatible DVD-R or DVD player with HDMI export, or
DVI-equipped devices like a computer. So you can display high-definition pictures on this TV in the digital form.
(1) How to use HDMI:
1. Connect one HDMI to the “HDMI” port and connect the other HDMI to device with
HDMI export as left figure.
Select the T-Line button,change source button can come into HDMI source.
3. The HDMI connectors allow the following TV and monitor display mod:
SDTV 720x576i, 50Hz /720x480i, 60Hz
EDTV 720x576p 50Hz /640x480p 60Hz
HDTV 1920x1080i 50/60Hz
1280x720p 50/60Hz
VGA 640x480 60Hz
Notes:
1.Your TV supports HDCP(High-bandwidth Digital Content Protection).This Is a system for protecting DVD content
outputted via DVI from being copied. It provides a secure digital link between a video source (DVD, PC, etc.)
and your TV. Content is encrypted at the source device to prevent unauthorized copies from being made.
2.Digital devices from different manufacturers have the possibility of differing output standards which may cause
difficulties for the television to properly display.
3.In case no signal is detected from your HDMI device, turn off the HDMI device and then on again.

22’’ LCD TV AOC L22W851B
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4.To get an optimal viewing, it is advised to turn your DVD player to one of the following TV display
standards:1280x720p 50hz.
3> S-Video Input: Connect the S-Video cable to DVD player, Laser Disc player,
videocassette recorder or camcorder. pin
4> Audio Input: Connect the audio signal source. (PC, DVD player, Laser Disc
player, videocassette recorder or camcorder) to the Audio Input ports.
5> Video Input: Connect the video signal source. (PC, DVD player, Laser Disc player, videocassette recorder or
camcorder) (The audio is for S-Video and AV)
TIPS
Care of the screen
Do not rub or strike the screen with anything hard as this may scratch, mar, or damage the screen permanently.
Unplug the power socket before cleaning the screen. Dust the TV by wiping the screen and the cabinet with a soft,
clean cloth. If the screen requires additional cleaning, use a clean, damp cloth. Do not use liquid cleaners or aerosol
cleaners.
Mobile telephone warning
To avoid disturbances in picture and sound, malfunctioning of your TV or even damage to the TV, keep away your
mobile telephone from the TV.
End of life directives
We are paying a lot of attention to produce environmentally friendly in green focal areas. Your new receiver contains
materials which can be recycled and reused.
At the end of its life specialized companies can dismantle the discarded receiver to concentrate the reusable
materials and to minimize the amount of materials to be disposed of.
Please ensure you dispose of your old receiver according to local regulations.

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2.4 Front Panel Control Knobs
CONTROL KNOBS
There is a wide range of video and audio equipment that can be connected to your TV. The following connection
diagrams show you how to connect them.
Power : Press this button to turn on the TV or allow the TV to enter standby mode.
If the TV is in standby mode, the indicator at the front will illuminates amber.
Menu : Press this button to display or exit the OSD menu.
CH(▲
): When the OSD menu appears, press these two buttons to select the
item you want to execute; when no OSD menu appears, use to change channels in TV
mode.
Vol(+ -) : When the OSD menu appears, press these two buttons to confirm the selected item;
when no OSD menu appears, use to adjust the volume.
Input: Press this button to change input source.

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3. Input/Output Specification
3.1 RGB Signal input
15 - Pin Color Display Signal Cable
Pin No.
Description
Pin No.
Description
1
Red Video
9
No Pin!
2
Green Video
10
Sync Ground
3
Blue Video
11
Not Used
4
Not Used
12
Serial Data for DDC
5
Ground
13
H-Sync.
6
Red Video Ground
14
V-Sync.
7
Green Video Ground
15
Serial Clock for DDC
8
Blue Video Ground
3.2 CVBS/S-VIDEO/ SCART / INPUTS
Composite Video
Video system
NTSC/PAL/SECAM
Amplitude
1.0Vpp (including sync )
Impedance
75 ohm terminated
S-Video
Video system
NTSC/PAL/SECAM
Y signal amplitude
1.0Vpp (including sync )
C signal amplitude
0.286Vpp
Impedance
75 ohm terminated
SCART (RGB)
Video system
NTSC/PAL/SECAM
R/G/B signal amplitude
0.7Vpp
CVBS signal amplitude
1.0Vpp (including sync )
Impedance
75 ohm terminated
SCART
(Composite)
Video system
NTSC/PAL/SECAM
Amplitude
1.0Vpp (including sync )
Impedance
75 ohm terminated

22’’ LCD TV AOC L22W851B
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3.3 Compatible Mode Table
MODE
COMPATIBLE INPUTS
STANDARD
RESOLUTION
Composite
SVHS
YPBPR
RGB
HDMI
720x400 @ 70Hz
No
No
No
Yes
Yes
640x480 @ 60Hz
No
No
No
Yes
Yes
640x480 @ 72Hz
No
No
No
Yes
Yes
640x480 @ 75Hz
No
No
No
Yes
Yes
VESA
800x600 @ 60Hz
No
No
No
Yes
Yes
VESA
800x600 @ 72Hz
No
No
No
Yes
Yes
VESA
800x600 @ 75Hz
No
No
No
Yes
Yes
MAC
832x624 @ 75Hz
No
No
No
Yes
Yes
VESA
1024x768 @ 60Hz
No
No
No
Yes
Yes
VESA
1024x768 @ 70Hz
No
No
No
Yes
Yes
VESA
1024x768 @ 75Hz
No
No
No
Yes
Yes
1280x768@ 60Hz
No
No
No
Yes
Yes
1280x1024 @60Hz
No
No
No
Yes
NO
VESA
1440x900@ 60Hz
No
No
No
Yes
NO
VESA
1680x1050@ 60Hz
No
No
No
Yes
NO
NTSC
480I(60Hz)
Yes
Yes
Yes
NO
YES
DVD
480p(60Hz)
No
No
Yes
NO
Yes
PAL
576I(50Hz)
Yes
Yes
Yes
NO
Yes
DVD
576p(50Hz)
No
No
Yes
NO
Yes
720p(50/60Hz)
No
No
Yes
NO
Yes
1080i (50/60Hz)
No
No
Yes
NO
Yes

22’’ LCD TV AOC L22W851B
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4. Mechanical Instructions
1. Remove the screws remarked in red to remove the base.
2. Remove the screws remarked in red to remove the rear cover.

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3.Remove the screws remarked in red to remove BKT –STAND-SUPPORT
4.Remove the screws remarked in red to remove shield

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6. Remove the screw remarked in red to remove the side frame.
7. Remove the screw remarked in red to remove the main board, power board and tuner board.
8. Remove the screw remarked in red to remove the key board.

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9. Remove the screw remarked in red to remove the bezel.
10. Remove the screws remarked in red to remove main frame