BenQ Q74A User manual

Q74A
Service Manual

Q74A Service Manual
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Contents
PRECAUTIONS................................................................................................. 4
ITEMS ............................................................................................................ 6
HOW TO CONNECT THE SEVERAL CABLES TO THE LCD MONITOR.......................... 7
▶Setting up the LCD monitor..................................................................... 7
ADJUSTING THE MONITOR................................................................................ 8
Q74A SPECIRICATIONS...................................................................................... 9
▶Q74A Specifications .................................................................................. 9
DISPLAY MODES............................................................................................ 10
PowerSaver..................................................................................................... 10
OSD MENU.................................................................................................... 11
▶Menu Tree............................................................................................ 11
FACTORY SET ................................................................................................ 12
BURN-IN MODE ............................................................................................. 12
INVERTER & POWER ...................................................................................... 13
▶Inverter & POWER(Q74A)........................................................................ 13
▶Specification ......................................................................................... 13
▶Electrical Characteristics........................................................................... 13
▶Pin Connection ...................................................................................... 14
TROUBLESHOOTING ...................................................................................... 15
▶No operating at all................................................................................... 15
▶Doesn’t display on LCD............................................................................ 16
EXPLODE VIEW ............................................................................................. 18
▶Q74A.................................................................................................. 18
PART LIST ..................................................................................................... 19
▶Q74A Mechanical Part List ........................................................................ 19
▶Q74AAD B/D Part List ............................................................................ 20
▶Q74A FUNCTION KEY B/D Part List........................................................... 23
▶Q74A FUNCTION LED B/D Part List........................................................... 23
▶Inverter & POWER BD Part List(FLF1742-20A) .............................................. 24
▶Inverter & POWER BD Part List(FLF1742-20A) .............................................. 25
CIRCUIT DIAGRAM ........................................................................................ 26
▶AD B/D(Q74A)...................................................................................... 26
▶Inverter & POWER B/D(FLF1742-20A) ........................................................ 31
PCB Layout .................................................................................................... 34
▶AD B/D TOP SILK (Q74A) ....................................................................... 34

Q74A Service Manual
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▶AD B/D TOP PATTERN (Q74A) ................................................................. 35
▶AD B/D BOTTOM SILK (Q74A) ................................................................36
▶AD B/D MASK TOP (Q74A) ..................................................................... 37
▶AD B/D MASK BOTTOM (Q74A) .............................................................. 38
▶FUNC B/D TOP SILK (Q74A).................................................................... 39
▶FUNC KEY B/D BOTTOM PATTERN (Q74A)................................................ 39
▶FUNC LED B/D TOP SILK (Q74A) ............................................................. 39
▶FUNC LED B/D BOTTOM PATTERN (Q74A)................................................ 39

Q74A Service Manual
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Q74A
PRECAUTIONS
Warning : The following information will help you avoid the risk of electric shock,
serious injury, and death.
zPlug the power cord into a properly grounded outlet.
There is the risk of electric shock.
zIf you hear a noise or smell smoke from the computer or adaptor, unplug the power cord
immediately, and call the service center.
There is the risk of electric shock or fire.
zDo not overload an electrical outlet with too many devices.
There is the risk of fire.
zDo not unplug from the outlet by pulling the power cord or when your hands are wet.
There is the risk of electric shock or fire.
zDo not bend the power cord excessively or place heavy objects on it. Keep children and pets
away from the power cord as they may damage the power cord. There is the risk of electric
shock or fire.
zDo not use a damaged power cord or plug. Make sure the plug fits snugly into the outlet.
There is the risk of electric shock or fire.
zDo not expose the monitor to the direct sun light.
zDo not block the fan louvers.
There is the risk of fire or damage to the monitor.
zDo not attempt to disassemble, fix, or modify the monitor.
There is the risk of electric shock or fire.
zKeep the monitor away from high temperature, humidity, and dust.
Operating environment = 0 ~ 40 Degrees Celsius
Operating environment = 30 ~ 80 Relative Humidity
zDo not allow any object or liquid to enter inside the monitor.
There is the risk of electric shock, fire, or damage to the monitor.

Q74A Service Manual
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Caution : The following information will help you avoid the risk of minor ofr moderate
injury,or damage to the monitor.
zUse a proper voltage/current level indicated.
zDo not clean the LCD with abrasive chemicals.
There is the risk of damage to the LCD.
zDo not scratch and damage the LCD with sharp objects.
zKeep the monitor away from objects and electrical appliances that may generate
electromagnetic fields.
zPlace the monitor on a flat, stable surface.
The monitor may fall and there is the risk of damage or injury.
zUnplug the power cord when the monitor is not in use for a prolonged period of time.
Instruction for Cleaning the Monitor
zMake sure the power cord is unplugged.
zDo not spill or pour liquid on the monitor.
zCleaning the LCD panel
1. Use a clean, soft cloth to wipe off dust from the LCD.
2. If still not clean, wipe the LCD with a clean soft cloth with a small amount of glass cleaner
without alcohol or ammonia.
zCaution
Do not use alcohol or ammonia based cleaning products. Abrasive chemicals, such as alcohol or
ammonia, may damage the monitor. The company is not responsible for the damages to the monitor
caused by the use of alcohol or ammonia based cleaning products.

Q74A Service Manual
ITEMS
◈ LCD Monitor
◈ Stand
◈ Power Cord
◈ 15pin D-Sub Cable
◈ User Manual
◈ 24pin DVI Cable *1
◈ Audio Cable *2
*1 : For DVI Model Only. *2 : For Audio Model Only.
Notice
Please make sure the following items are included with your monitor.
If any items are missing, contact your dealer. .
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Q74A Service Manual
HOW TO CONNECT THE SEVERAL CABLES TO THE LCD
MONITOR
▶Setting up the LCD monitor
No. Name Cable connections
1 Power Power Cord
2 PC 15-pin D-Sub Signal Cable
3 DVI DVI-D Cable *1
4 SPK IN Audio Cable *2
5 SPK OUT External Speaker Cable *2
*1 : For DVI Model Only
*2 : For Audio Model Only
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Q74A Service Manual
ADJUSTING THE MONITOR
The Function Control Buttons
How to use the Function Key
Menu Key:
1. First click : The OSD main menu appears.
2. Second click : The OSD main menu disappears.
Select Key : Select a command function.
Down Key :
1. Move the on-screen highlighted comand
item to the next one.
2. Decrease the current option value.
Mute Key : *2
Sound MUTE ON/OFF Button.
Up Key :
1. Move the on-screen highlighted comand
item to the previous one.
2. Increase the current option value.
Auto Key : *1
This will optimize image quality automatically.
MWE Key : You can manually adjust the screen to your
environment on the computer.
ex.) Internet, Games, Movies ...
*1 : For Analog Mode Only , *2 : For Audio Model Only.
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Q74A Service Manual
Q74ASPECIRICATIONS
▶Q74A Specifications
MODE Analog Digital
Type TFT active matrix
17 inch
Size 337.92 X 270.336 (mm)
Pixel Pitch 0.264 X 0.264 (mm)
Panel
Display Color 8-bit (16,777,216 colors)
Basic 1280x1024@60Hz Display
Resolution Maximum 1280x1024@75Hz 1280x1024@60Hz
Horizontal 31.5 ~ 80KHz 31 ~64KHz
Frequency
vertical 56 ~ 75Hz 59 ~ 61Hz
15 pin D-Sub 24pin DVI-D
Connectors Speaker Input/Headphone Output(Audio Cable) *1
Tilting Degree (U/D) -5° ~ 20° Degree
Plug&Play VESA DDC 1/2B
Input Internal type : 100~240V AC,50/60Hz, 0.5A
Consumption Under 40W (Speaker Max 4W *1)
Power
Standby mode 1W less
Power Management PowerSaver
Temperature 0~25℃ (32℉~77℉) Environmental
Consideration Humidity 90% less
Dimensions Outside 387mm * 185mm * 396mm (W*D*H)
Weight 3.9kg
*1 : For Audio Model Only
Notice
This monitor can be installed on any Plug & Play compatible system.
Interaction of the monitor and computer systems will provide the best
operating conditions and monitor settings. In most cases, monitor
installation will proceed automatically, unless the user wishes to select
alternate settings.
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Q74A Service Manual
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DISPLAY MODES
Mode Resolution
Horizontal
Frequency(KHz)
Vertical
Frequency(Hz)
Pixel Clock
(MHz)
Sync
Polarity(H/V)
720 X 400 31.468 70.087 28.322 -/+
31.468 59.940 25.175 -/-
35.000 66.670 30.240 -/-
VGA 640 X 480
37.500 75.000 31.500 -/-
37.879 60.300 40.000 +/+
48.077 72.188 50.000 +/+
SVGA 800 X 600
46.875 75.000 49.500 +/+
48.363 60.004 65.000 -/-
56.476 70.000 75.000 -/-
XGA 1024 X 768
60.023 75.029 78.750 +/+
63.981 60.020 108.000 +,-/+,-
SXGA 1280 X 1024 79.976 *1 75.025 *1 135.000 *1 +/+ *1
*1 : For Analog Mode Only.
PowerSaver
State Power
Consumption
Recovery
Time LED Color
ON Under 40W - Green
OFF Less than 1W Within 2 Sec Amber