Asus VH236H - 23" LCD Monitor User manual

Service Manual ASUS VH236H&VH232H
1
R
LCD Monitor Service Manual
Model: ASUS VH236H&VH232H
D
SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUAL ARE FURNISHED FOR
INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT ANY TIME WITHOUT NOTICE, AND
SHOULD NOT BE CONSTRUED AS A COMMITMENT BY ASUS. ASUS ASSUMES NO RESPONSIBILITY
OR LIABILITY FOR ANY ERRORS OR INACCURACIES THAT MAY APPEAR IN THIS MANUAL,

Service Manual ASUS VH236H&VH232H
2
Index
Revision Lists………………………………….............................................................................. 3
Important Safety Notice…………………………………………………………………………………..4
1. Monitor Specification..............................……….........................................................................5
2. Operation Instruction…………………………………………………………………………………..6
2.1. General Instructions...........................…............................................................................ 6
2.2.Control Button…………….…..............……......................................................................... 6
2.3.OSD Menu…………….…...........................…......................................................................8
3. Input/Output Specification............……………..........................................................................11
3.1. Input Signal Connector............…………............................................................................11
3.2. Power Supply Requirements............................................................................................ 12
3.3. Factory Preset Display Modes…….................................................................................. 13
4. Block Diagram…..….....................………….............................................................................15
4.1.Software Flow Chat..........................................................................................15
4.2 Electircal Block Diagram........................................................................................................17
5. Schematic Diagram……………………....…............................................................................ 19
5.1. Main Board……….............................................................................................................19
5.2. Power Board...…….......................................................................................................... 26
5.3. Key Board…………….......................................................................................................28
6. PCB Layout...………................................................................................................................29
6.1. Main Board………............................................................................................................29
6.2. Power Board…................................................................................................................. 31
6.3. Key Board……………................................... ...................................................................33
7. Disassemble & Assemble SOP.……………….. ............................................................... …..34
8. ISP Instruction………..............................................................................................................52
9. DDC Instruction…………………………........... .......................................................................50
10. Color/White Balance Adjustment……………........................................................................ 71
11. Trouble Shooting……………………….................................................................................. 73
12. Exploded View…..……………………..... ......................................................................... .....79
13. BOM List………………………………….............................................................................. 80

Service Manual ASUS VH236H&VH232H
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Revision List
Version Release Date Revision History Customer Model TPV Model Name
VH236H HDRSACNKXCUSRC
A00 Jan,08,2009 Initial release
VH232H HDRSA2NTXCUSRP

Service Manual ASUS VH236H&VH232H
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Important Safety Notice
Safety information
• Before setting up the monitor, carefully read all the documentation that came with the package.
• To prevent fire or shock hazard, never expose the monitor to rain or moisture.
• Never try to open the monitor cabinet. The dangerous high voltages inside the monitor may result in serious
physical injury.
• If the power supply is broken, do not try to fix it by yourself. Contact a qualified service technician or your retailer.
• Before using the product, make sure all cables are correctly connected and the power cables are not damaged. If
you detect any damage, contact your dealer immediately.
• Slots and openings on the back or top of the cabinet are provided for ventilation. Do not block these slots. Never
place this product near or over a radiator or heat source unless proper ventilation is provided.
• The monitor should be operated only from the type of power source indicated on the label. If you are not sure of the
type of power supply to your home, consult your dealer or local power company.
• Use the appropriate power plug which complies with your local power standard.
• Do not overload power strips and extention cords. Overloading can result in fire or electric shock.
• Avoid dust, humidity, and temperature extremes. Do not place the monitor in any area where it may become wet.
Place the monitor on a stable surface.
• Unplug the unit during a lightning storm or if it will not be used for a long period of time. This will protect the monitor
from damage due to power surges.
• Never push objects or spill liquid of any kind into the slots on the monitor cabinet.
• To ensure satisfactory operation, use the monitor only with UL listed computers which have appropriate configured
receptacles marked between 100-240V AC.
• If you encounter technical problems with the monitor, contact a qualified service technician or your retailer.
WARNING
• Before you lift or reposition your monitor, it is better to disconnect the cables and power cord. Follow the correct
lifting techniques when positioning the monitor. When lifting or carrying the monitor, grasp the edges of the
monitor.Do not lift the display by the stand or the cord.
• Cleaning. Turn your monitor off and unplug the power cord. Clean the monitor surface with a lint-free, non-abrasive
cloth. Stubborn stains may be removed with a cloth dampened with mild cleaner.
• Avoid using a cleaner containing alcohol or acetone. Use a cleaner intended for use with the LCD. Never spray
cleaner directly on the screen, as it may drip inside the monitor and cause an electric shock.
WARNING: Information to prevent injury to yourself when trying to complete a task.
CAUTION: Information to prevent damage to the components when trying to complete a task.
IMPORTANT: Information that you MUST follow to complete a task.
NOTE: Tips and additional information to aid in completing a task.

Service Manual ASUS VH236H&VH232H
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1. Monitor Specifications
Model VH232H VH236H
Panel Size 23”W 23”W
True Resolution 1920X1080 1920X1080
Brightness (Max.) ≧300CD/m
2
≧300CD/m
2
Intrisinc Contrast Ratio ≧1000:1 ≧1000:1
Viewing Angle (CR=10) ≧160°(V), ≧160°(H) ≧160°(V), ≧160°(H)
Color Saturation (NTSC) 72% 72%
Display Colors 16.7M 16.7M
Response Time 5ms 2ms
Satellite Sperker 2W x 2 stere 2W x 2 stereo
HDMI Input HMDI HMDI
DVI Input Yes Yes
D-SUB Input Yes Yes
Audio Line-in Yes Yes
Earphone Output Yes Yes
SPIDIF Output Yes Yes
Power On 50W 50W
Tilt +20°～-5° +20° ～-5°
VESAWall Mounting Yes (100mm x 100mm) Yes (100mm x 100mm)
Phys. Dimension 548.80 x 349.9x 220 548.80 x 349.9x 220
Box Dimesion (WxHxD) 638 x 478 x 171 638 x 478 x 171
Net Weight (Esti.) 5.5 5.5
Gross Weight (Esti.) 7.3 7.3
Voltage Rating AC: 100～240V (Built-in) AC: 100～240V (Built-in)

Service Manual ASUS VH236H&VH232H
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2. Operation Instruction
2.1 General Instructions
Press the power button to turn the monitor on or off. The other control buttons are located at the front of the
panel of the monitor.
By changing these settings, the picture can be adjusted to your personal preferences.
-The power cord should be connected.
-Connect the video cable from the monitor to the video card.
-Press the power button to turn on the monitor, the power indicator will light up.
2.2 Control Button
Rear View

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Front View

Service Manual ASUS VH236H&VH232H
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2.3 OSD Menu
2.3.1 How to reconfigure
1. Press the MENU button to activate the OSD menu.
2. Press ▼and ▲to navigate through the function.
Highlight and activate the desired function by pressing the
MENU button. If the function selected has a sub-menu,
press ▼and ▲again to navigate through the sub-menu
functions. Highlight and activate the desired sub-menu
function by pressing the Menu function.
3. Press ▼and ▲to change the settings of the selected
function.
4. To exit the OSD menu, press the button. Repeat step
2 and step 3 to adjust any other function.
2.3.2 OSD Function Introduction
1. Spendid
This function contains five sub-functions you can
select for your preference. Each mode has the Reset
selection, allowing you to maintain your setting or
return to the preset mode.
• Scenery Mode: Best choice for scenery photo display with SPLENDID™ Video Enhhancement.
• Standard Mode: Best choice for document editing with SPLENDID™ Video Enhancement.
• Theater Mode: Best choice for movie with SPLENDIF™ Video Enhancement.
• Game Mode: Best choice for game playing with SPLENDID™ Enhancement.
• Night View Mode: Best choice for dark-scene game or move with SPLENDID™ Video Enhancemetn.
• In the Standard Mode, the Satuation and ASCR functions are not user-configurable.
• In the other modes, the sRGB function is not user-configurable.

Service Manual ASUS VH236H&VH232H
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2. Image
You can adjust brightness, contrast, sharpness,
saturation, position (VGA only), and focus (VGA only)
from this main function.
• Brightness: the adjusting range is from 0 to 00. is a hotkey to activate this function.
• Contrast: the adjusting range is from 0 to 00.
• Sharpness: the adjusting range is from 0 to 00.
• Saturation: the adjusting range is from 0 to 00.
• Position: adjusts the horizontal postition (H-Position) and the vertical position (V-Position) of the image.
The adjusting range is from 0 to 00.
• Focus: reduces Horizonal-line noise and Vertical-line noise of the image by adjusting (Phase) and (Clock)
separately. The adjusting range is from 0 to 00.
• Phase adjusts the phase of the pixel clock signal. With a wrong phase adjustment, the screen
shows horizontal disturbances.
• Clock (pixel frequency) controls the number of pixels scanned by one horizontal sweep. If the
frequency is not correct, the screen shows vertical stripes and the image is not proportional.
3. Color
Select the image color you like from this function.
• Color Temp.: contains five color modes including Cool,
Normal, Warm, sRGB, and User mode.
• Skin Tone: contains three color modes including
Reddish, Natural, and Yellowish.
In the User mode, colors of R (Red), G (Green),
and B (Bluee) are userconfigurable; the adjusting range is
from 0- 00.

Service Manual ASUS VH236H&VH232H
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4. Input Select
In this function, you can select VGA, DVI, and HDMI
input source (Only for some models).
5. System Setup
Allow you to adjust the system.
• Volume: the adjusting range is from 0 to 00. is a
hotkey to activate this function.
• OSD Setup: adjusts the horizontal postition (H-Position)
and the vertical position (V-Position) of the OSD. The
adjusting range is from 0 to 00. In the OSD Timeout
selection, you can adjust the OSD timeout from 0 to 20.
• Language: there are ten languages for your selection,
Including English, German, Italian, French, Dutch, Spanish,
Russian, Traditional Chinese, Simplified Chinese,
Japanese, and Korean.
• Aspect Controls: adjusts the aspect ratio to “Full” or “4:3”.
• Information: shows the monitor information.
• Reset: “Yes” allows you to revert to the preset mode.

Service Manual ASUS VH236H&VH232H
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3. Input/Output Specification
3.1 Input Signal Connector
Analog connectors
Pin No. Description Pin No. Description
1. Red Video 9. +5V Supply
2. Green Video 10. Logic Ground
3. Blue Video 11. Monitor Ground
4. Monitor Ground 12. DDC-Serial Data
5. DDC-Return 13. H-Sync
6. Red Ground 14. V-Sync
7. Green Ground 15. DDC-Serial Clock
8. Blue Ground
VGA connector layout
DVI connectors
Pin
No. Description Pin No. Description Pin No.
Description
1. RX2- 9. R X1- 17. RX0-
2. RX2+ 10. RX1+ 18. RX0+
3. RX2 Shield 11. RX1 Shield 19. RX0 Shield
4. NC 12. NC 20. NC
5. NC 13. NC 21. NC
6. DDC Clock 14. +5V Power 22. RX Clock Shield
7. DDC Data 15. Ground 23. RX Clock+
8. NC 16. Hot Plug Detection 24. RX Clock-

Service Manual ASUS VH236H&VH232H
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HDMI Connectors
Pin No. Description Pin No. Description
1. TMDS Data2+ 11. TMDS Clock Shield
2. TMDS Data2 Shield 12. TMDS Clock
3. TMDS Data2- 13. CEC
4. TMDS Data1+ 14. Reserved (N.C. on device)
5. TMDS Data1 Shield 15. SCL
6. TMDS Data1- 16. SDA
7. TMDS Data0+ 17 DDC/CEC Ground
8. TMDS Data0 Shield 18 +5V
9. TMDS Data0- 19 Hot Plug Detect
10. TMDS Clock+
3.2 Power Supply Requirements
A/C Line voltage range 100 V ~ 240 V
A/C Line frequency range 50 ±3Hz, 60 ±3Hz
Input Voltage transients 90-264 voltage AC for 10 sec @40
Current 1.5A max at 100V; 0.8A max at 240 V
Peak surge current < 60A peak at 240 VAC and cold starting
< 30A peak at 120VAC and cold starting
Leakage current < 3.5mA
Power line surge No advance effects (no loss of information or defect)
with a maximum of 1 half-wave missing per second

Service Manual ASUS VH236H&VH232H
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3.3 Factory Preset Display Modes
VESA Modes, Factory Preset Timings

Service Manual ASUS VH236H&VH232H
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VESA Modes, User Available Timings
HDMI Supported Primary Timings
Modes not listed in the above tables may not be supported. For optimal resolution, we
recommendthatyou choose a mode listed in the above tables

Service Manual ASUS VH236H&VH232H
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4. Block Diagram
4.1 Software Flow Chat
1
2
N
Y
5
Y
N
10
Y
N
12
Y
N
7
Y
N
6
4
3
8
9
14
11
13
Y
N
15
Y
N
16
17
19
Y
N
18

Service Manual ASUS VH236H&VH232H
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1) MCU initializes.
2) Is the EPROM blank?
3) Program the EPROM by default values.
4) Get the PWM value of brightness from EPROM.
5) Is the power key pressed?
6) Clear all global flags.
7) Are the AUTO and SELECT keys pressed?
8) Enter factory mode.
9)
Save the power key status into EPROM.
Turn on the LED and set it to green color.
Scalar initializes.
10) In standby mode?
11) Update the lifetime of back light.
12) Check the analog port, are there any signals coming?
13) Does the scalar send out an interrupt request?
14) Wake up the scalar.
15) 15) Are there any signals coming from analog port?
16)
Display "No connection Check Signal Cable" message. And go into standby mode after the message
disappears.
17) Program the scalar to be able to show the coming mode.
18) Process the OSD display.
19) Read the keyboard. Is the power key pressed?

Service Manual ASUS VH236H&VH232H
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4.2 Electrical Block Diagram
4.2.1 Main Board
Flash Memory
EN25F20
(U402)
Panel Interface
(CN403)
Crystal
14.318MHZ
(X401)
Keypad Interface
(CN401)
Scalar TSUMO88GDI（VH236H）
TSUMU88EDI（VH232H）
(Include MCU, ADC, OSD)
(U401)
D-Sub Connector
(CN404)
EEPROM
M24C02
(U407) H sync
V sync
RGB
DVI Connector
(CN405)
EEPROM
M24C02
(U
40
6
)
D-DATA
D-CLK
DVI_SCL
DVI_SDA
EEPROM
M24C16
(U403)
HDMI Connector
(CN501)
EEPROM
M24C02
(U
504
)
HDMI_SCL
HDMI_SDA
VGA_
SCL
VGA_
SDA
HDMI_CLK
HDMI_DATA
Earphone
R & L Speakers

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4.2.2 Inverter/Power Board
DIM
EMI filter
Start Circuit: R904, R905
PWM Control
IC LD7576
Transformer
AC input
16V
ON/OFF
Control
Feedback
Circuit
Transformer MOSFET
Lamp
ON/OFF
5V
Bridge
Rectifier
and Filter
Feedback
Circuit
Rectifier
diodes
CN902
Output
Circuit
PWM Control
Over Voltage

Service Manual ASUS VH236H&VH232H
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5. Schematic
5.1 Main Board
715G3221 1
TO-252
+5V
CN101
CONN
1
2
3
4
5
6
7
8
9
10
R105 22K 1/16W 5%
C104
0.1uF 16V
VCC3.3
Adj_BACKLIGHT 5
VCC1.8 5
+5V
FB102
300 OHM
1 2
VCC1.8
+5V_AUD
+
C103
220uF/16V
R108
56K 1/16W 5%
+
C106
100uF/16V
D101
SM340A
+5V
C121
0.1uF 16V
A
B
3 9Thursday, December 25, 2008 715G3221-1
 < >
2.0.POWER
G3221-1-X-X-4-081225
OEM MODEL Size
Rev
Date Sheet of
TPV MODEL
PCB NAME

T P V ( Top Victory Electronics Co . , Ltd. )
Key Component
絬    
DIM
+ C102
NC/220uF/16V
Q102
NC/AO3401
R104
10K 1/16W 5%
ESD_5V
C110
0.1uF 16V
Q104
AO4411
1
2
3
4
8
7
6
5
S
S
S
G
D
D
D
D
Q101
2N3904S-RTK/PS
R101
10K 1/16W 5%
C118
0.1uF 16V
C108
0.1uF 16V
R103
10K 1/16W 5%
VLCD
VCC3.3
R114
0R05 1/8W FB101
120 OHM
1 2
Q103
2N3906S-RTK/PS
1
23
ESD_5V
C101
NC/0.1uF 16V
R106
10K 1/16W 5%
C117
NC/0.22uF
C109
0.1uF 16V
C122
1NF16V
TO-252
+5V 5,7
VCC3.3
+5V_EDID
C114
0.1uF 16V
on_Panel5
R112
1.5 OHM 2W
R111
10K 1/10W 5%
+5V_EDID
C115
0.1uF 16V
+ C111
47uF/16V
5VCC 4,7
5VCC
R109 22K 1/16W 5%
C116
0.1uF 16V
+
C107
100uF/16V
C105
0.1uF 16V
U101 G1084-33T43Uf
23
1
VOUTVIN
GND
+5V
R110
150K OHM 1/16W 5%
ON/OFF
VLCD
6
R113
1K 1/16W 5%
+
C113
100uF/16V
+5V
U102
AZ1117D-1.8-E1 23
1
OUTIN
GND
+5V
R107
10K 1/16W 5%
R102 1K 1/16W 5%
on_BACKLIGHT 5
+
C112
100uF/16V
+5V_AUD 8
VCC3.3 5
VCC3.3
ZD101
RLZ5.6B

Service Manual ASUS VH236H&VH232H
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RIN 5
DVI5V 3
R460 56 OHM 1/16W
ESD_5V 3
DVI5V
VGA5V
ESD_5V
D407
BAV70
3
1 2
R486 22K 1/16W 5%
DVI_SCL1
5
R465
75R 1/16W 5%
C450
0.1uF 16V
FB410 30 OHM
1 2
VSI
C447
22pF
R468 1K 1/16W 5%
FB103
300 OHM
1 2
DCK- 5
DAT1+
候 綼
U103
DVI5V
C449
0.1uF 16V
RED+
C448
0.1uF 16V
DD1+ 5
DDC_WP
DD0- 5
R476
2K2 1/16W 5%
C443 0.047uF
R488 0R05 1/16W ESD_5V
D413
BAV70
3
1 2
VSI
GREEN-
C454
0.22uF
GIN 5
VSYNC 5
DAT0+
GREEN+
R478 100R 1/16W 5%
C441 1000pF
FB406 120 OHM1 2
DD2- 5
VGA_SDA
R471 4K7 1/16W 5%
R482 4K7 1/16W 5%
U405
AZ1045-04QU
1
2
3
4
56
7
8
9
10 Line-1
Line-2
VDD
Line-3
Line-4NC
NC
GND
NC
NC
HSYNC 5
DAT1-
DVI_HPD_SW
5
R485 100R 1/16W 5%
DVI_HPD
C440 0.047uF
DD2+ 5
DVI_HPD
C452
0.22uF
R495
10K 1/16W 5%
VGA5V
DD0+ 5
R494 0R05 1/16W
GNDR 5
R467
75R 1/16W 5%
R473 1K 1/16W 5%
DVI_SCL
R462 100R 1/16W 5%
FB411 30 OHM
1 2
ZD408
RLZ5.6B
1 2
BIN 5
U407
M24C02-WMN6TP
1
2
3
45
6
7
8A0
A1
A2
VSSSDA
SCL
WP
VCC
DVI_SDA
DVI5V
R491 0R05 1/16W
+5V_EDID1
DVI_SDA1
5
+5V_EDID1
R487 0R05 1/16W
R484 100R 1/16W 5%
U410
AZC099-04S
1
2
3 4
5
6
I/O1
GND
I/O2 I/O3
VDD
I/O4
Close to CN101
R461 470R 1/16W 5%
ZD406
RLZ5.6B
1 2
R459 56 OHM 1/16W
R458 56 OHM 1/16W
U404
AZ1045-04QU
1
2
3
4
56
7
8
9
10 Line-1
Line-2
VDD
Line-3
Line-4NC
NC
GND
NC
NC
C120
0.1uF 16V
DD1- 5
VGA_DET
VGA_SCL
C119
0.1uF 16V
DDC_WP 5
BLUE+
R489 0R05 1/16W
U408
AZC099-04S
1
2
3 4
5
6
I/O1
GND
I/O2 I/O3
VDD
I/O4
R481 4K7 1/16W 5%
C442 0.047uF
GNDG 5
A
B
4 9Thursday, December 25, 2008 715G3221-1
 < >
3.0.INPUT
G3221-1-X-X-4-081225
OEM MODEL Size
Rev
Date Sheet of
TPV MODEL
PCB NAME

T P V ( Top Victory Electronics Co . , Ltd. )
Key Component
絬   
CN405 JACK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
26 25
DAT2-
DAT2+
2/4shield
DAT4-
DAT4+
DDC SCL
DDC SDA
VSYNC
DAT1-
DAT1+
1/3shield
DAT3-
DAT3+
+5V
SYNC GND
HPD
DAT0-
DAT0+
0/5shield
DAT5-
DAT5+
clk shield
clk+
clk-
GND GND
+5V_EDID
FB412 30 OHM
1 2
CN404
DB15
1
6
2
7
3
8
4
9
5
11
12
13
14
15 10
1716
DAT2-
DCLK+
VGA_SDA1
5
C439 0.047uF
DDC_WP
VGA_DET 5
DCK+ 5
GREEN+
R493 0R05 1/16W
C444 0.047uF
R483 10K 1/16W 5%
Close to CN102
R492 0R05 1/16W
R475
2K2 1/16W 5%
DAT2+
DAT0- R490 0R05 1/16W
DCLK-
ESD_5V
C438 0.047uF
VGA_SCL1
5
HSI
C445
0.1uF 16V
DVI_SCL
R477 100R 1/16W 5%
U406
M24C02-WMN6TP
1
2
3
45
6
7
8A0
A1
A2
VSSSDA
SCL
WP
VCC
HSI
RED-
候 綼
U401
VGA_SDA
Close to CN101
U409
AZC099-04S
1
2
3 4
5
6
I/O1
GND
I/O2 I/O3
VDD
I/O4
R472
10K 1/16W 5%
DDC_WP 5
RED+
SOG 5
R466
75R 1/16W 5%
R463 100R 1/16W 5%
ZD407
RLZ5.6B
1 2
VGA5V
R470 4K7 1/16W 5%
BLUE+
R464 100R 1/16W 5%
R469 1K 1/16W 5%
C446
22pF
Q406
2N3906S-RTK/PS
1
23
C123
1NF16V
GNDB 5
+5V_EDID
DVI_SDA
BLUE-
VGA_SCL