BenQ BL2423PT User manual

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Product Service Manual –LevelⅡ
Service Manual for BenQ:
Version: 2nd
Date:12-13-2016
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 (Aug. 2016)
©Copyright BenQ Corporation 2016. All Right Reserved.
BL2423PT
9H.LFSLA.TBA
Applicable for All Regions

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Content Index
Abbreviations & Acronyms........................................................................................................................................3
1. About this Manual...................................................................................................................................................5
1.1 Important ............................................................................................................................................................5
1.2 Trademark ..........................................................................................................................................................5
2. Introduction.............................................................................................................................................................6
2.1 RoHS (2002/95/EC) Requirements –Applied to all countries require RoHS.....................................................6
2.2 Safety Warning and Notice Installation ..............................................................................................................6
2.3 Compliance Statement .......................................................................................................................................7
3. General Description................................................................................................................................................8
4. Related service information...................................................................................................................................8
5. Product Overview ...................................................................................................................................................9
5.1 Monitor Specifications ........................................................................................................................................9
5.1.1 Certification....................................................................................................................................................12
5.2 Panel Inspection Specification..........................................................................................................................18
Level 1 Cosmetic / Appearance / Alignment Service ............................................................................................26
Visual Inspection & Cleaning..................................................................................................................................26
Software/Firmware Upgrade Process ....................................................................................................................26
Factory mode..........................................................................................................................................................34
Adjustment / Alignment Procedure ....................................................................................................................41
Level 2 Circuit Board and Standard Parts Replacement ......................................................................................65
Product Exploded View ..........................................................................................................................................65
Six Angles’ View .....................................................................................................................................................67
Product Disassembly/Assembly.........................................................................................................................68
Troubleshooting......................................................................................................................................................80
Appendix 1 –Screw List / Torque ...........................................................................................................................86

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Abbreviations & Acronyms
A
ADC
Analog 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 Synchronization
D
DLP
Digital Light Processing / Texas Instruments®
DMD
Digital Micro mirror Device
DRAM
Dynamic RAM
DVI
Digital Visual Interface
DVI-D
Digital Visual Interface-digital
DVI-I
Digital Visual 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
I2C
Integrated IC bus
L
LED
Light Emitting Diode
LVDS
Low Voltage Differential Signal, data transmission system for high
M
MOSFET
Metal Oxide Semiconductor Field Effect Transistor
N

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NC
Not Connected
NVM
Non Volatile Memory: IC containing TV related data (for example, options)
O
OSD
On Screen Display
P
PC
Personal Computer
PCB
Printed Circuit Board (or PWB)
R
RC
Remote Control transmitter
RGB
Red, Green and Blue. The primary color signals for TV. By mixing levels of R, G
and B, all colors (Y/C) are
ROM
Read Only Memory
S
SDA
Data signal on I2C 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= Color 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 color 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

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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 complaints.
If the product service or maintenance require replacing any parts, please confirming the RoHS requirement before
replace them.
2.2 Safety Warning and Notice Installation
1. Do not use your monitor under any of the following environmental conditions:
Extremely high or low temperature, or in direct sunlight
Dusty places
Highly humid, exposed to rain, or close to water
Exposed to vibrations or impacts in places such as cars, buses, trains, and other rail vehicles
Near heating appliances such as radiators, heaters, fuel stoves, and other heat-generating items.
An enclosed place (such as a closet or bookcase) without appropriate ventilation
An uneven or sloping surface
Exposed to chemical substances or smoke
2. Do not block vents and openings by clothes or curtains.
3. Carry the monitor carefully.
4. Do not place the monitor face down on the floor or a desk surface directly. Otherwise, scratches on the panel
surface may occur.
5. Do not place heavy loads on the monitor to avoid possible personal injury or damage to the monitor.
6. Ensure that children do not hang or climb onto the monitor.
7. Keep all packing bags out of reach of children.

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Operation
1. To protect your eyesight, please refer to the user manual to set the optimal screen resolution and the viewing
distance.
2. To reduce eye fatigue, take a break on a regular basis while using the monitor.
Avoid taking either one of the following actions for a long time. Otherwise, burn marks may occur.
Use the monitor in the aspect ratio of 4:3, 5:4, 16:9 or 16:10.
Place a still image (such as an OSD menu, fixed text or image) on the screen.
3. To avoid possible damage to the monitor, do not touch the monitor panel by hand, pen, or any other sharp
objects.
4. Excessively frequent plug and unplug of video connectors (D-sub) may cause damage to the monitor.
5. This monitor is designed mainly for personal use. If you want to use the monitor in a public place or a harsh
environment, contact your nearest BenQ service center for assistance.
6. To avoid possible electric shock, do not dissemble or repair the monitor.
7. If a bad smell or an abnormal sound appears to come from the monitor, contact your nearest BenQ service
center for assistance immediately.
Cleaning
1. Ensure that the power is unplugged before cleaning your monitor.
2. Use a monitor cleaner and a soft cloth to clean your monitor.
3. Do not use solvents such as alcohol to clean your monitor.
Power
1. To avoid possible damage to the monitor, do not use it in a region where power supply is unstable.
2. Ensure that the power cord is connected to a grounded power outlet before turning on the monitor.
3. Use only the power cord provided by BenQ.
4. Never use a power cord that appears to be damaged or frayed.
5. To avoid possible danger, observe the total electric load when using the monitor with a (multi-outlet) extension
cord.
6. Always turn off the monitor before unplugging the power cord.
2.3 Compliance Statement
Caution: This Optical Storage Product contains a Laser device. Refer to the product specifications and your local
Laser Safety Compliance Requirements.

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3. General Description
This new LCD (Liquid Crystal Display) monitor BenQ BL2423PT offers numerous features and functions, for
example:
Panel Type: IPS+LED
Minimal space requirements thanks to slim casing
Optimum ergonomic characteristics (totally distortion-free, excellent picture definition and color purity right into
the corners)
Contrast ratio 1,000:1 (Panel) / 20M:1 (DCR), brightness 350nits
MAX. resolution (1920x1080)
Contrast (typ.): 1,000:1
Presentation of up to 16.7 M colors (in conjunction with an appropriate graphics card)
Automatic scanning of horizontal frequencies from 30 to 83 kHz and refresh rates (vertical frequencies) from 50
to 75 Hz (absolutely flicker-free)
Digital screen controller with microprocessor for storing 6 different display modes
Freely adjustable color alignment for matching the screen colors to the colors 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
This operating manual contains important information you require to start up and run your LED monitor.
This specification defines the requirements for the 24″ MICROPROCESSOR based Multi-mode supported high
resolution color LED monitor. The monitor can be directly connected to general 15-pin VGA connector, 24-pin DVI
connector. Also support 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 1920x1080 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
Service Web Site
eSupport Website:
BenQer: http://esupport.benq.com/v2
ASP: http://esupport.benq.com/

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5. Product Overview
5.1 Monitor Specifications
BL2423PT
Configuration:
VGA+DVI_D+DP1.2
Panel Type (TN / VA / IPS)
IPS+LED
Panel Model
LM238WF1 SLK1
Panel Size
23.8” (16:9)
Display Area
23.8 inches(604.70mm) diagonal
Max. Resolution
1920x1080
Pixel Pitch
0.2745
Brightness (Typ.)
250
Contrast Ratio (Typ.) / DCR (Min.)
1000:1 (Panel) / 20M:1 (DCR)
ViewingAngle (H/V), CR≧10
178/178
Display Colors
16.7M
Response Time
14ms (Typ., GTG_AVR)
GtG response Time
4ms(Premium)/8ms(High)
sRGB ratio
100%
Color Space
72% NTSC
Panel maker
LGD
BenQ SenseyeTM Technology
Yes
BenQ SenseyeTM Preset Modes
10 Modes (by hotkey) : sRGB / CAD/CAM / Animation(0~10) /
Standard / Low Blue Light/
Movie / Photo / Eco / M-Book / User
BenQ SenseyeTM Demo Modes
5 Modes :
CAD/CAM / Animation / Movie / Photo / M-Book
Color Temperature Selection
Normal (6500°K) / Reddish (5700°K) / Bluish (9300°K) / User Mode
Hor. Frequency (KHz)
30kHz~83KHz
Ver. Frequency (Hz)
50Hz~75Hz
Video Bandwidth (MHz)
205MHz

10
Speakers (built-in)
1W x 2
Volume
Adjustment 0~100
Mute
On/ Off
PC Video Input
Yes
HDMI Input
NA
AV Video Input
x
Audio Line In
Yes
Headphone Jack
Yes
USB2.0
Yes (2*downstream(Rear), 1*upstream)
D-Sub (VGA)
Yes
Display Port
Yes (DisplayPort1.2*1)
Voltage Rating
90~264 AC Build in
Power-On Mode
TBD
Standby Mode
<0.5W
Power Off Mode
<0.3W
Chassis Colors
Follow ID Artwork
Carton
Brown carton
Power LED
White (On)/ Amber (Standby)
OSD Key
Touch Key
Tilt (Up / Down)
-5°to 20°
Height Adjustment
140mm
Pivot
90°
Swivel
45/45
VESAWall Mount
100x100
MNT without stand
4230g, L:563.2mm*:W:73mm*H:338.7mm
Kensington Lock
Yes
Container Loading (40’)
Refer to B405
Container Loading (20’)
Refer to B405
OSD
17 Languages (English / Francais / Deutsch / Italiano / Espanol /
Polish / Czech / Hungarian / Serbo-croatian / Romanian / Netherlands
/ Russian / Swedish / Protuguese / Japanese / Chinese / S-Chinese)
Win 7/Win 8/Win 8.1/Win10
Yes