Toshiba LCD-AD174TW User manual

AD174TW TOSHIBA
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SERVICE MANUAL
TOSHIBA
LCD-AD174TW
THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY.EVERY
REASONABLE EFFORT HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL;
WE CANNOT GUARANTEE THE ACCURACY OF THIS INFORMATION AFTER THE DATE OF
PUBLICATION AND DISCLAIMS RELIABILITY FOR CHANGES, ERRORS OR OMISSIONS.
MANUFACTURE DATA ：Jul-25-2006

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Table of Contents
Table of Contents ----------------------------------------------------------------------------- 02
Revision List ------------------------------------------------------------------------------------04
1. Product Feature ----------------------------------------------------------------------------05
2. LCD Monitor Description -----------------------------------------------------------------05
3. Operation Instructions --------------------------------------------------------------------06
3.1 General Instructions ------------------------------------------------------------------06
3.2 Control Buttons ------------------------------------------------------------------------06
3.3 Adjusting The Picture ----------------------------------------------------------------06
4. Electrical Performance Parameter ------------------------------------------------- 07
4.1 Input Signal Connector --------------------------------------------------------------07
4.2 Factory Preset Display Modes -----------------------------------------------------08
4.3 Power Supply --------------------------------------------------------------------------09
4.3.1 Input/Output Requirements ---------------------------------------------------09
4.3.2 Inverter Max Brightness ------------------------------------------------------- 09
4.3.3 Inverter Min Brightness --------------------------------------------------------10
4.4 Panel Specification ----------------------------------------------------------------10
4.4.1 General Feature (BOE HT170E13-101) ----------------------------------10
4.4.2 Optical Characteristics -------------------------------------------------------11
4.4.3 Parameter guide line for CCFL Inverter -----------------------------------12
5. Block Diagram ------------------------------------------------------------------------------13
5.1 Monitor Exploded View -------------------------------------------------------------13
5.2. Disassemble Process --------------------------------------------------------------15
5.3 Software Flow Chart ------------------------------------------------------------------19
5.4. Block Diagram ---------------------------------------------------------------------------21

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5.4.1 Electrical Block Diagram ------------------------------------------------------21
5.4.2 Inverter/Power Board Block Diagram --------------------------------------22
6. Schematic -----------------------------------------------------------------------------------24
6.1 TOP ------------------------------------------------------------------------------------24
6.2 Main Board ---------------------------------------------------------------------------25
6.3 PWPC Board -----------------------------------------------------------------------29
6.3 KeyPad Board -----------------------------------------------------------------------31
6.4 Audio Board ------------------------------------------------------------------------32
7. PCB Layout ---------------------------------------------------------------------------------33
7.1 Main Board ----------------------------------------------------------------------------33
7.2 Inverter/Power Board ---------------------------------------------------------------35
7.3 Keypad Board -------------------------------------------------------------------------36
7.4 Audio Board ------------------------------------------------------------------------36
8. Maintainability ------------------------------------------------------------------------------36
8.1 Equipments and Tools Requirements -------------------------------------------36
8.2 Trouble Shooting ---------------------------------------------------------------------37
8.2.1 Main Board ---------------------------------------------------------------------37
8.2.2 Key Pad Board ------------------------------------------------------------------39
8.2.3 Power/Inverter Board ------------------------------------------------------40
9. White-Balance, Luminance Adjustment ---------------------------------------------42
10. EDID Content -----------------------------------------------------------------------------44
11. BOM List -----------------------------------------------------------------------------------45
11.1 AD174T——T781KK6NJ4D4ABP ------------------------------------------45~62

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Revision List
Revision Date Change Description

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1. PRODUCT FEATURE
43.2 cm (17”) a-si TFT Active matrix LCD panel, 0.264mm dot pitch.
Microprocessor controlled scan technology
20 factory presets,
Vertical refresh rate 55Hz to 75 Hz
Horizontal frequency 24kHz to 80kHz
Resolutions: 640 x 350 up to 1280 x 1024
Universal power supply designed for worldwide application
VESA DPMS compliant
VESA DDC2B compliant
ROHS compliant
2. LCD MONITOR DESCRIPTION
The LCD Monitor will contain a main board, an inverter/power board, keypad board which house the
flat panel control logic, brightness control logic and DDC.
The power board will provide AC to DC Inverter voltage to drive the backlight of panel and the main
board chips each voltage.
Power board
(
Include: ada
p
ter
,
inverter
)
Flat Panel and
CCFL backlight
Main Board
Keyboard
RS232 Connector
For white balance
adjustment in factory
mode
HOST Computer
CCFL Drive.
Video signal, DDC
Monitor Block Diagram

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3. OPERATING INSTRUCTIONS
3.1 GENERAL INSTRUCTIONS
Press the power button to turn the monitor on or off. The other control buttons are located
at front 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.
3.2 CONTROL BUTTONS
3.2.1 KEY CONTROL
3.3 ADJUSTING THE PICTURE
Power On/Off
Input signal
select / Auto
Adjustment
Volume +, - &
Menu Select
OSD Menu

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CONTROL FUNCTION
Display Mode Normal, Text, Cinema, Photo, TV
ECO Mode
Brightness
Contrast
Color temperature sRGB, 6500K, 7200K, 9300K, User
LCD Adjustment
Clock
Phase
H. Position
V. Position
Other Setup
Smooth
OSD H. Position
OSD V. Position
OSD Timeout
OSDTransparency On Off
Mode message On Off
Language Japanese English
Reset
Exit
4. ELECTRICAL PERFORMANCE PARAMETER
4.1 INPUT SIGNAL CONNECTOR
PIN NO. DESCRIPTION PI N NO. DESCRIPTION
1. Red Video 9. +5V
2. Green Video 10. Detect Cable
3. Blue Video 11. RS232
4. RS232 12. DDC-Serial Data
5. DDC-Rturn 13. H-Sync
6. R-Ground 14. V-Sync
7. G-Ground 15. DDC-Serial Clock
8. B-Ground
VGA Connector layout
15
610
11 15

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PIN NO. DESCRIPTION PI N NO. DESCRIPTION
1. TMDS data 2 - 13. TMDS data 3 + (NC)
2. TMDS data 2 + 14. + 5V Power
3. TMDS data 2/4 Shield 15. GND(return for +5v,hsync,vsync)
4. TMDS data 4 – (NC) 16. Hot Plug Detect
5. TMDS data 4 + (NC) 17. TMDS data 0 -
6. DDC Clock 18. TMDS data 0 +
7. DDC Data 19. TMDS data 0/5 Shield
8. Analog Vertical Sync 20. TMDS data 5 –(NC)
9. TMDS data 1 - 21. TMDS data 5 +(NC)
10. TMDS data 1 + 22. TMDS Clock Shield
11. TMDS data 1/3 Shield 23. TMDS Clock +
12. TMDS data3 – (NC) 24. TMDS Clock -
DVI-D 24 PIN CONNECTOR
4.2 FACTORY PRESET DISPLAY MODES：
VESA MODES
Horizontal Vertical
Mode Resolution Total
Nominal
Frequency
+/- 0.5kHz
Sync
Polarity
Nominal
Freq.
+/- 1 Hz
Sync
Polarity
Nominal
Pixel
Clock
(MHz)
640x480@60Hz 800 x 525 31.469 N 59.940 N 25.175
640x480@72Hz 832 x 520 37.861 N 72.809 N 31.500
VGA
640x480@75Hz 840 x 500 37.500 N 75.00 N 31.500
800x600@56Hz 1024 x 625 35.156 N/P 56.250 N/P 36.000
800x600@60Hz 1056 x 628 37.879 P 60.317 P 40.000
800x600@72Hz 1040 x 666 48.077 P 72.188 P 50.000
SVGA
800x600@75Hz 1056 x 625 46.875 P 75.000 P 49.500
1024x768@60Hz 1344x806 48.363 N 60.004 N 65.000
1024x768@70Hz 1328x806 56.476 N 70.069 N 75.000
XGA
1024x768@75Hz 1312x800 60.023 P 75.029 P 78.750
1280x1024@60Hz 1688x1066 63.981 P 60.020 P 108.000
SXGA 1280x1024@75Hz 1688x1066 79.976 P 75.025 P 135.000
1152x864@75HZ 1600x900 67.500 P 75.000 P 108.00
*** 1280x960@60HZ 1800x1000 60.000 P 60.000 P 108.00

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NEC MODE
VGA 640x400@56Hz 848 x 440 24.827 N 56.424 N 21.052
IBM MODES
Horizontal Vertical
Mode Resolution Total
Nominal
Frequency
+/- 0.5kHz
Sync
Polarity
Nominal
Freq.
+/- 1 Hz
Sync
Polarity
Nominal
Pixel
Clock
(MHz)
DOS 720x400@70Hz 900 x 449 31.469 N 70.087 P 28.322
DOS 640x350@70Hz 800 x 449 31.469 P 70.087 N 25.175
MAC MODES
VGA 640x480@67Hz 864 x 525 35.000 N 66.667 N 30.240
SVGA 832x624@75Hz 1152 x 667 49.725 N 74.551 N 57.2832
XGA 1024x768@75Hz 1328 x 804 60.241 N 74.927 N 80.000
All modes will automatically optimize the screen size "AUTO-config" "function", except certain screen
pattern, such as only some characters display on black background.
4.3 POWER SUPPLY
4.3.1 INPUT/OUTPUT REQUIREMENTS
PARAMETER RANGE
AC Input Voltage 100 to 240V
AC Input Frequency 50 ±3Hz, 60 ±3Hz
AC Input Current 1.5A max at 100V ; 0.8A max at 240 V
Inrush Current < 55A peak at 240 VAC and cold starting
Leakage Current <3.5 mA MAX
Power line surge No advance effects (no loss of information or defect)
with a maximum of 1 half-wave missing per second

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4.3.2 INVERTER MAX BRIGHTNESS (Vadj:5.0v), LOAD=100KΩX4
(ROOM TEMPERATURE 25 ±4 )℃℃
ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK
Input voltage Vin 10.8 12 13.2 V
Input current Iin 1700 1900 2100 mA FOR 4 LOAD
Output Current Iout 6.5 6.5 7.0 mA FOR 1 LOAD
Frequency F 30 --- 70 KHZ FOR 1 LOAD
H.V Load Vload 560 700 840 Vrms RL=100KΩ
Start voltage Vst 1600 --- --- Vrms RL=100KΩ
Protect delay time PDT 0.1 1 Sec
4.3.3 INVERTER MIN BRIGHTNESS (Vadj:0.0v), LOAD=100KΩX4
(ROOM TEMPERATURE 25℃±4℃)
ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK
Input voltage Vin 10.8 12 13.2 V
Input current Iin 400 450 500 mA FOR 4 LOAD
Output Current Iout 3.0 3.5 4.0 mA FOR 1 LOAD
Frequency F 30 --- 70 KHZ FOR 1 LOAD
Start voltage Vst 1600 --- --- Vrms RL=100KΩ
H.V Load Vload 560 700 840 Vrms RL=100KΩ
4.4 PANEL SPECIFICATION
4.4.1 General Feature ( BOE HT170E13-101 )
Parameter Specification Unit
Active area 337.92（H）x 270.336（V）mm
Number of pixels 1280（H）x 1024（V）pixels
Pixel Pitch 0.264（H）x0.264（V）mm

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Pixel arrangement RGB Vertical stripe
Display colors 16,194,227 colors
Display mode Normally White
Dimensional outline 358.5（H）x296.5（V）x 17.0（D）typ. mm
Weight 1900(max.) gram
Surface Treatment Haze 25%,3H
Contrast 500cd/ m²(typ.) cd/m²
Luminance, White 300cd/m²(Center Typ) cd/m²
Response time 8ms(typ) ms
Power Consumption ＜35W
AC100V 50/60Hz
Viewing
Angle(CR>10) R/L 150(Typ.), U/D 135(Typ.)
Back-light Top/Bottom edge side, 4-CCFL type
4.4.2 OPTICAL CHARACTERISTICS
[ VDD=5.0V, Frame rate=60Hz, Clock=54MHz, IBL=6.5mA, Ta=25±4℃]
Parameter Symbol Condition Min Typ Max Unit Remark
θ3 65 75 - Deg
Horizontal θ9 65 75 - Deg
θ12 65 75 - Deg
Viewing Angle
Vertical θ6
CR>10
50 60 - Deg
Note 1
contrast ratio CR 450 700 - Deg Note 2
Luminance of white YW250 300 -
cd/
m² Note 3
White luminance uniformity △Y 75 - - % Note 4
Wx 0.283 0.313 0.343
White Wy 0.299 0.329 0.359
Rx 0.617 0.647 0.677
Red Ry 0.307 0.337 0.367
Gx 0.253 0.283 0.313
Green Gy 0.570 0.600 0.630
Bx 0.112 0.142 0.172
Reproduction of
color
Blue By 0.054 0.084 0.114
Note 5
Tr -
Response time Td - 8 12 ms Note 6
Cross talk CT
θ=0℃
(Center)
Normal
Viewing
- - 2.0 % Note 7

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4.4.3 PARAMETER GUIDE LINE FOR CCFL INVERTER.
Back-Light Unit：
Ta=25±2℃
Parameter Min. Typ. Max. Unit Remark
Power Supply Voltage VDD 4.5 5.0 5.5 V Note 1
Power supply Current IDD - 750 900 mA Note 1
Permissible Input Ripple Voltage VRF 100 mV VDD=5.0V
High Level Differential Input
Threshold Voltage VIH - +100 mV
Low Level Differential Input
Threshold Voltage VIL -100 - mV
Vcm=1.2V typ.
Back-light Lamp Voltage VBL 560 700 840 Vrms
Back-light Lamp Current IBL 3.0 6.5 7.0 mArms
Back-light Lamp operating
Frequency FL30 - 70 KHz Note 2
1400 Vrms 25℃,Note 3
Lamp Start Voltage
1700 Vrms 0℃,Note 3
Lamp Life 40000 50000 hrs IBL=6.5mA
PD- 3.75 4.5 W
PBL 18.33 W IBL=6.5mA,Note 4
Power Consumption
Ptotal 22.1 22.83 W

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5. BLOCK DIAGRAM
5.1 MONITOR EXPLODED VIEW

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MAIN COMPONENT LIST
NO. Part Name Part Number Quantity
1 BEZEL 34G1544-AUU-1 1PCS
2 SCREW Q1G330-6-120 2PCS
3 KEY PCB KEPC780KODVP 1PCS
4 KEY PAD 33G4848-1 1PCS
5 LENS 33G4849-C-1 1PCS
6 SPEAKER 78G332-501-L/GL 1PCS
7 SCREW Q1G1030-6-120 2PCS
8 PANEL-BKT-R 15G6208-R-2A 1PCS
9 SCREW M1G330-4-120 4PCS
10 PANEL 750GLK70-13-2 1PCS
11 MYLAR FOR POWER PCB 52G8025-11-805 1PCS
12 MYLAR FOR MAIN FRAME 52G8025-800-TO 1PCS
13 SHIELD J85G8121-3A 1PCS
14 SCREW M1G330-4-120 4PCS
15 MYLAR FOR HINGE BKT 85G6025-11-840 1PCS
16 HINGE-BKT 15G6204-1 1PCS
17 SCREW M1G330-6-120 4PCS
18 REAR COVER J34G1545-UU-1L-1 1PCS
19 POWER PCB PWPC1742HD1P 1PCS
20 AUDIO PCB AUPC780A0DP 1PCS
21 MAIN PCB CBPC780KK5DAP 1PCS
22 PANEL-BKT-L J15G6208-L-2A 1PCS
23 RUBBER FOOT 12G394-3 4PCS
STAND Ass’y LIST
24 BASE 34G1547-UU-L 1PCS
25 SCREW M1G340-8-120 4PCS
26 STAND 34G1546-UU-L 1PCS
27 CLAMP 37G4695-1-C 1PCS
28 HINGE 37G6033-2 1PCS
29 SCREW M1G330-6-120 3PCS

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5.2 DISASSEMBLE PROCESS
5.2.1 Tools：
Glove
Cross screwdriver
Six angle sleeve spanner
Prize equipment or abandoned IC card
Screw box
Cloth cushion
5.2.2 Disassemble process:
1、Tidy up the worktable, spread the cushion, put the monitor on it ,the front side
downwards.(Fig.1)
2、Disassemble the fixed 4 screws of the stand, showed in Fig.2. Remove the base and
stand following the direction the arrowhead showed, refer to Fig.3.
3、Disassemble the fixed 5 screws of the back cover, refer to Fig.4.
4、Insert plastic card or abandoned IC card in the bottom of the monitor, between the bezel
and back cover, and remove the back cover. Refer to Fig.5,6,7,8.
5、Disassemble 4 screws that fix the speaker and another 2 screws that fix the KEPC board,
showed in Fig. 9,10.
6、Disassemble 2 screws and 4 pins that fix the shield, refer to Fig.11,12, and remove the
shield following the direction arrowhead showed, Fig.13 ,14.
7、Disassemble connect pins of the main board to panel, showed in Fig.15,16.
8、Remove the bezel, showed in Fig.17. Do not scratch the panel.
9、Disassemble the screws that fix the panel, showed in Fig.18,19.
10、That’s all, the process is over.
5.2.3 Pictures:
（Fig.1）（Fig.2）
Cushion

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（Fig.3）（Fig.4）
（Fig.5）（Fig.6）
（Fig.7）（Fig.8）
（Fig.9）
（Fig.10）

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（Fig.11）（Fig.12）
（Fig.13）（Fig.14）
（Fig.15）（Fig.16）
（Fig.17）

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（Fig.18）
（Fig.19）
（Fig.20）

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5.3 SOFTWARE FLOW CHART
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
1
5
Y
N
16
1
7
19
Y
N
18

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1) MCU initialize.
2) Is the eeprom blank ?
3) Program the eeprom by default values.
4) Get the PWM value of brightness from eeprom.
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 eeprom.
Turn on the LED and set it to green color.
Scaler initialize.
10) In standby mode ?
11) Update the life time of back light.
12) Check the analog port, are there any signals coming ?
13) Does the scalar send out a interrupt request ?
14) Wake up the scalar.
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 disappear.
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 ?