BenQ G920HDA User manual

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Applicable Country & Regions: Europe/China
Service Manual for BenQ:
LCD G920HDA
(D-SUB+ Black Bezel)
Product Service Manual – Level 1~2
Version: 1st
Date:01-13-2009
Notice:
For RO to input specific “Legal Requirement” in specific NS regarding to responsibility and
liability statements.
Please check BenQ’s eSupport web site, http://esupport.benq.com, to ensure that you have the
most recent version of this manual.
First Edition (January, 2009)
©
Copyright BenQ Corporation 2009. All Right Reserved.

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Content Index
Abbreviations & Acronyms........................................................................................................................................3
1. About This Manual..................................................................................................................................................5
1.1 Important ............................................................................................................................................................5
1.2 Trademark...........................................................................................................................................................5
2. Introduction.............................................................................................................................................................5
2.1 RoHS (2002/95/EC) Requirements – Applied to all countries require RoHS.....................................................5
2.2 Safety Notice......................................................................................................................................................6
2.3 Compliance Statement .......................................................................................................................................6
3. General Description................................................................................................................................................6
4. Related service information...................................................................................................................................7
5. Product Overview ...................................................................................................................................................8
5.1 Monitor Specifications........................................................................................................................................8
5.2 Packing...............................................................................................................................................................9
Level 1 Cosmetic / Appearance / Alignment Service ............................................................................................12
Visual Inspection & Cleaning..................................................................................................................................12
Software/Firmware Upgrade Process ....................................................................................................................12
Adjustment / Alignment Procedure.........................................................................................................................16
Level 2 Circuit Board and Standard Parts Replacement ......................................................................................28
Product Exploded View ..........................................................................................................................................28
Six angles’ view......................................................................................................................................................29
Product Disassembly..............................................................................................................................................30
Block Diagram........................................................................................................................................................35
Schematic Diagram................................................................................................................................................37
Troubleshooting Guide ...........................................................................................................................................45
PCB LAYOUT.........................................................................................................................................................52
Appendix 1 – Screw List / Torque ...........................................................................................................................54

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Abbreviations & Acronyms
A
ADC Analogue to Digital Converter
AFC Automatic Frequency Control: control signal used to tune to the correct frequency
B
BenQ BenQ Corporation
BTSC Broadcast Television System Committee
C
CPU Central Process Unit
CVBS Composite Video Blanking and Synchronisation
D
DLP Digital Light Processing / Texas Instruments®
DMD Digital Micromirror Device
DRAM Dynamic RAM
DVI Digital Video Interface
DVI-I Digital Video Interface-Integrated
E
EEPROM Electrically Erasable and Programmable Read Only Memory
F
FLASH FLASH memory
G
G-TXT Green Teletext
H
HDMI High Definition Multimedia Interface, digital audio and video interface
HP Head Phone
I
I
2
C Integrated IC bus
L
LED Light Emitting Diode
LVDS Low Voltage Differential Signalling, data transmission system for high
M
MOSFET Metal Oxide Semiconductor Field Effect Transistor
N
NC Not Connected
NVM Non Volatile Memory: IC containing TV related data (for example, options)
O
OSD On Screen Display

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P
PC Personal Computer
PCB Printed Circuit Board (or PWB)
R
RC Remote Control transmitter
RGB Red, Green, and Blue. The primary colour signals for TV. By mixing levels of R, G, and B,
all colours (Y/C) are
ROM Read Only Memory
S
SDA Data signal on I
2
C bus
SDRAM Synchronous DRAM
SW Sub Woofer / Software
T
THD Total Harmonic Distortion
V
VGA Video Graphics Array
Y
YPbPr Component video (Y= Luminance, Pb/ Pr= Colour difference signals B-Y and R-Y, other
amplitudes w.r.t. to YUV)
Y/C Video related signals: Y consists of luminance signal, blanking level and sync; C consists
of colour signal.

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1. About This Manual
The purpose of Service Manual is to provide a guide line to engineers to repair different models. The
appearance and capability is introduced in this Service Manual. It is better for repair engineer to have a rough
idea of this model through reading the Service Manual. Please do pay attention to the item part of the
disassembly when repair the machine and also do the protection of panel any time. When repairing the circuit
board, please follow the requirement of RoHS and refer to the circuit diagram and repairing process that
attached in the Service Manual. The method of firmware updated, the way of using the menu and some
information that may be used when repairing are also attached in the Service Manual that provide repair
engineer various choice.
1.1 Important
Only trained service personnel who are familiar with this BenQ Product shall perform service or
maintenance to it. Before performing any maintenance or service, the engineer MUST read the
“Important Safety Information”.
1.2 Trademark
2. Introduction
This section contains general service information, please read through carefully. It should be stored for easy
access place.
2.1 RoHS (2002/95/EC) Requirements – Applied to all countries require RoHS.
The RoHS (Restriction of Hazardous Substance in Electrical and Electronic Equipment Directive) is a legal
requirement by EU (European Union) for the global electronics industry which sold in EU and some counties
also require this requirement. Any electrical and electronics products launched in the market after June 2006
should meet this RoHS requirements. Products launched in the market before June 2006 are not required to
compliant with RoHS parts. If the original parts are not RoHS complaints, the replacement parts can be non
ROHS complaints, but if the original parts are RoHS compliant, the replacement parts MUST be RoHS

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complaints.
If the product service or maintenance require replacing any parts, please confirming the RoHS requirement
before replace them.
2.2 Safety Notice
1. Make sure your working environment is dry and clean, and meets all government safety requirements.
2. Ensure that other persons are safe while you are servicing the product.
3. DO NOT perform any action that may cause a hazard to the customer or make the product unsafe.
4. Use proper safety devices to ensure your personal safety.
5. Always use approved tools and test equipment for servicing.
6. Never assume the product’s power is disconnected from the mains power supply. Check that it is
disconnected before opening the product’s cabinet.
7. Modules containing electrical components are sensitive to electrostatic discharge (ESD). Follow ESD safety
procedures while handling these parts.
8. Some products contain more than one battery. Do not disassemble any battery, or expose it to high
temperatures such as throwing into fire, or it may explode.
9. Refer to government requirements for battery recycling or disposal.
2.3 Compliance Statement
1. Caution: This Optical Storage Product contains a Laser device. Refer to the product specifications and your
local Laser Safety Compliance Requirements.
3. General Description
This new LCD (Liquid Crystal Display) monitor BenQ G920HDA offers numerous features and functions, for
example:
●TFT display (Thin Film Transistor; active matrix)
●minimal space requirements thanks to slim casing
●optimum ergonomic characteristics (totally distortion-free, excellent picture definition and colour purity right into
the corners)
●high degree of brightness and good contrast

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●high resolution (1920x1080)
●presentation of up to 16.7 million colours (in conjunction with an appropriate graphics card)
●automatic scanning of horizontal frequencies from 30 to 63 kHz and refresh rates (vertical frequencies) from 50 to
76 Hz (absolutely flicker-free)
●digital screen controller with microprocessor for storing 21 different display modes
●freely adjustable colour alignment for matching the screen colours to the colours of various input and output
devices
●convenient operation via integrated OSD (On-Screen-display) menu
●VESA-DDC compatibility
●plug&play capability
●power management for reducing power consumption when the computer is not in use
●compliance with the recommendations in accordance with TCO’03
This operating manual contains important information you require to start up and run your LCD monitor.
This specification defines the requirements for the 18.5” MICROPROCESSOR based Multi-mode supported high
resolution color LCD monitor. This monitor can be directly connected to general 15-pin D-sub VGA connector, also
supports VESA DPMS power management and plug & play function.
Additional information
Due to the nature of liquid crystal display (LCD) technology, the picture resolution is always fixed. For the best
display performance, please set the display resolution to 1366x768 pixels with an aspect ratio of 16:9. This is called
“Native Resolution” or maximal resolution – that is, the clearest picture. Lower resolutions are displayed on a full
screen through an interpolation circuit. Image blurring across pixel boundaries can occur with the interpolated
resolution depending upon the image type and its initial resolution.
4. Related service information
This Service Manual contains general information. There are 2 levels of service:
Level 1: Cosmetic / Appearance / Alignment Service
Level 2: Circuit Board or Standard Parts Replacement

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Service Web Site
eSupport URL:http://esupport.benq.com
5. Product Overview
5.1 Monitor Specifications
LCD Panel
Driving system TFT Color LCD
Size 470mm(18.5")
Pixel pitch 300（per one triad）X300
Display Area 409.8 x 230.4
Viewable angle 170/160，（CR≧10）
Contrast 1000:1
Dynamic contrast
ratio 10000: 1 (typical)
Brightness 300 cd/m
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Response time 5ms(typical on/off)
Input
Video RGB analog 0.7 Vpp/75 Ohm positive
Synchronization TTL separate signal connection 15-pin mini D-sub cable
H-Frequency 30 - 63 kHz Multi- frequency monitor
V-Frequency 50 - 76 Hz modes within these parameters
Display Colors 16.7M Colors
Image diagnostics Digital, OSD Technology, AUTO key (automatic image setting)
Controls 5 buttons and AUTO key
Max. Resolution 1366x768
Power management VESA DPMS, EPA
EPA ENERGY
STAR®
Max.
power
consumption 67W (max)
saving mode < 2 Watt
Operating voltage Automatic switched mode power supply, 100-240 V, 50-60 HZ
Environmental
Considerations Operating Temp: 0°to 35°C Operating Humidity: 10% to 85%
Dimension (H x W x D) 365.5mm x 582.6mm x 197.4mm
Weight (N. W.) 7 KG

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5.2 Packing
When packing the monitor into the carton, please follow the pictures as below.
Using the EPE bag to pack the monitor without base.
Using the EPE bag to pack the base

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Using the EPS to pack the monitor
Putting the base and user manual in the position as the picture shows above.

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Putting the monitor and accessories into the carton.
Power cord
User manual

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Level 1 Cosmetic / Appearance / Alignment Service
Visual Inspection & Cleaning
• Cleaning. Always unplug your monitor from the wall outlet before cleaning. Clean the LCD monitor surface with a
lint-free, non-abrasive cloth. Avoid using any liquid, aerosol or glass cleaners.
• Slots and openings on the back or top of the cabinet are for ventilation. They must not be blocked or covered. Your
monitor should never be placed near or over a radiator or heat source, or in a built-in installation unless proper
ventilation is provided.
• Never push objects or spill liquid of any kind into this product.
Software/Firmware Upgrade Process
1. When do the part, need the tools as follow:
a. An i486 (or above) personal computer or compatible.
b. Microsoft operation system Windows 95/98/2000/XP.
c. “ PORT95NT.exe” program
d. Software ISP SN Alignment kits
The kit contents:
a. ISP BOARD x1
b. Printer cablex1
c. VGA cable x1
2. Install the “PORT95NT.EXE”, and restart the computer.
Note: After installation, you must restart the PC to take the setup to effect.
3. Connect the ISP board as follow:

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4. The process of ISP write is as follows.
a. Double-click ，running the program as follows:
Connect to
the PC LPT
Connect to the
BenQ model

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b. Choose , click ,, running the program as follows:
c. Click icon, search the program” BenQ_G920HDA_RTD2525LH_AUO185_DCR_V100.H00”,
and click open:
d. Click icon, search the program” BenQ_G920HDA_RTD2525LH_AUO185_DCR_V100.H01”, and click
open:
e. Click icon, search the program” BenQ_G920HDA_RTD2525LH_AUO185_DCR_V100_EXTEND”,
and click open:

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f. Click icon, until appear the follow Fig, writer completed

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Adjustment / Alignment Procedure
Adjusting the Picture
You can use the OSD (On Screen Display) menu to adjust all the settings on your monitor.
Press the MENU key to display the following main OSD menu.
There are four main OSD menus:
1. Display
2. Picture
3. Picture Advanced
4. System
Use the or keys to highlight a menu item, and press the ENTER key to enter the Menu item settings.

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Display menu
1. Press the MENU key to display the main menu.
2. Press the or keys to select DISPLAY and then press the ENTER key to enter the menu.
3. Press the or keys to move the highlight to a menu item and then press the ENTER key to select that
item.
4. Press the or keys to make adjustments or selections.
5. To return to the previous menu, press the MENU button.
Item Function Operation Range
Auto
Adjustment
Optimizes and adjusts the
screen settings automatically for
you. The AUTO key is a
‘hot-key’ for this function.
When you connect a digital
video output using a digital
(DVI) cable to your monitor,
the AUTO key and the Auto
Adjustment function will be
disabled.
Press the ENTER
key to
select this option
and make
adjustment.
0 to 100
H. Position Adjusts the horizontal
position of the screen
image.
Press the or
keys to
adjust the value.
0 to 100
V. Position Adjusts the vertical
position of the screen
image.
0 to 100
Pixel Clock Adjusts the pixel clock 0 to 100

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frequency timing to
synchronize with the
analog input video signal.
Not applicable to a digital
input signal.
Phase Adjusts the pixel clock
phase timing to
synchronize with the
analog input video signal.
Not applicable to a digital
input signal.
0 to 63
Picture menu
1. Press the MENU key to display the main menu.
2. Press the or keys to select PICTURE and then press the ENTER key to enter the menu.
3. Press the or keys to move the highlight to a menu item and then press the ENTER key to select that
item.
4. Press the or keys to make adjustments or selections.
5. To return to the previous menu, press the MENU button.
Item Function Operation Range
Brightness
Adjusts the balance between light
and dark shades.
The function is not available
for use when Dynamic Contrast is
Press the key to
increase the brightness and
press the key to
decrease the brightness.
0 to 100

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on
Contrast
Adjusts the degree of difference
between darkness and lightness.
The function is not available
for use when Dynamic Contrast is
on.
Press the key to
increase the contrast and
press the key to
decrease the contrast.
0 to 100
Sharpness
Adjusts the clarity and visibility of
the edges of the subjects in the
image.
Press the key to
improve the crispness of
the display and press the
key to have softness
effect on the display.
1 to 5
Color - Press ENTER to enter the Color menu.
Normal
Allows video and still photographs
to be viewed with natural coloring.
This is the factory default color. Press the or keys
to
select this option.
0 to 100
Bluish
Applies a cool tint to the image and
is factory pre-set to the PC industry
standard white color.
0 to 63
Reddish
Applies a warm tint to the image and
is factory pre-set to the news print
standard white color.
User Mode
Tailors the image color tint. The
blend of the Red, Green and Blue
primary colors can be altered to
change the color tint of the image.
The default start setting is 50.
Decreasing one or more of the
colors will reduce their respective
influence on the color tint of the
image. e.g. if you reduce the Blue
level the image will gradually take
on a yellowish tint. If you reduce
Green, the image will become a
magenta tint.
Press the or keys
and the ENTER key to select
Red, Green, or Blue. Then
use Press the or
keys to make the color
adjustments.
• Red
(0 to 100)
• Green
(0 to 100)
• Blue
(0 to 100)
Reset Color
Resets the User Mode custom color
settings to the factory defaults.
Press the or keys
to
change the settings.
• YES
• NO

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Press MENU to leave the Color menu.
Dynamic Contrast
The function will increase the level
of contrast to provide sharper and
more detailed image quality.
Activating
Dynamic Contrast will disable
Brightness and Contrast controls.
Press the ENTER key to
select this option. Press
the or keys to
change the settings.
0 to 5
Picture Advanced menu
1. Press the MENU key to display the main menu.
2. Press the or keys to select PICTURE ADVANCED and then press the ENTER key to enter the menu.
3. Press the or keys to move the highlight to a menu item and then press the ENTER key to select that
item.
4. Press the or keys to make adjustments or selections.
5. To return to the previous menu, press the MENU button.