Acer AL1923 User manual

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AcerAL1923 (Dual)
Service Guide
Service guide files and updates are available on the CSD web: for more
information,
Please refer to http://csd.acer.com.tw/
100% Recycled Paper

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Copyright
Copyright © 2003 by Acer Incorporated. All rights reserved. No part of this publication may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language or computer language,
in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual or otherwise,
without the prior written permission of Acer Incorporated.
Disclaimer
The information in this guide is subject to change without notice. Acer Incorporated makes no
representations or warranties, either expresses or implied, with respect to the contents hereof and
specifically disclaims any warranties of merchantability or fitness for any particular purpose, Any Acer
Incorporated software described in this manual is sold or licensed “as is ”. Should the programs prove
defective following their purchase, the buyer (and not Acer Incorporated, its distributor, of its dealer)
assumes the entire cost of all necessary servicing, repair, and any incidental or consequential damages
resulting from any defect in the software.
Acer is a registered trademark of Acer Corporation.
Intel is a registered trademark of Intel Corporation.
Pentium and Pentium II/III are trademarks of Intel Corporation.
Other brand and product names are trademarks and/or registered trademarks of their respective holders.

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Conventions
The following conventions are used in this manual:
Screen messages Denotes actual messages that appear on screen
Note Gives bits and pieces of additional information related to
the current topic.
Warning Alerts you to any damage that might result from doing or
not doing specific actions.
Caution Gives precautionary measures to avoid possible hardware or
software problems.
Important Reminds you to do specific actions relevant to the
accomplishment of procedures.

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Preface
Before using this information and the product it supports, please read the following general information.
1. This Service Guide provides you with all technical information relating to BASICCONFIGURATION
decided for Acer’s “global” product offering. To better fit local market requirements and enhance product
competitiveness, your regional office MAY have decided to extend the functionality of a machine (e.g.
add-on card, modem, or extra memory capability). These LOCALIZED FEATURES will NOT be covered
in this generic service guide. In such cases, please contact your regional offices or the responsible
personnel/channel to provide you with further technical details.
2. Please not WHEN ORDERING FRU PARTS, that you should check the most up-to-date information
available on your regional web or channel. If, for whatever reason, a part number change is made, it will
not be noted in the printed Service Guide, for ACER-AUTHORIZED SERVICE PROVIDERS, your Acer
office may have a DIFFERENT part number code to those given in the FRU list of this printed Service
Guide. You MUST use the list provided by your regional Acer office to order FRU parts for repair and
service of customer machines.

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WARNING: (FOR FCC CERTIFIED MODELS)
NOTE: this equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference in a residential installation. This equipment generates, uses and can radiate radio
frequency energy, and if not installed and used in accordance with the instructions, may cause harmful
interference to radio communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television reception,
Which can be determined by turning the equipment off and on, the user is encouraged to try to correct the
interference by one or more of the following measures:
1. Reorient or relocate the receiving antenna.
2. Increase the separation between the equipment and receiver.
3. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
4. Consult the dealer or an experienced radio/TV technician for help.
NOTICE:
1. The changes or modifications not expressly approved by the party responsible for compliance could void
the user’s authority to operate the equipment.
2. Shielded interface cables and AC power cord, if any, must be used in order to comply with the emission
limits.
3. The manufacturer is not responsible for any radio or TV interference caused by unauthorized
modification to this equipment. It is the responsibility of the user to correct such interference.
As an ENERGY STAR® Partner our company has determined that this product meets the ENERGY STAR®
guidelines for energy efficiency.
WARNING:
To prevent fire or chock hazard, do not expose the monitor to rain or moisture. Dangerously high
voltages are present inside the monitor. Do not open the cabinet. Refer servicing to qualified
personnel only.

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PRECAUTIONS
lDo not use the monitor near water, e.g. near a bathtub, washbowl, kitchen sink, laundry tub,
Swimming pool or in a wet basement.
lDo not place the monitor on an unstable trolley, stand, or table. If the monitor falls, it can injure a
person and cause serious damage to the appliance. Use only a trolley or stand recommended by the
manufacture or sold with the monitor. If you mount the monitor on a wall or shelf, use a mounting kit
approved by the manufacture and follow the kit instructions.
lSlots and openings in the back and bottom of the cabinet area provided for ventilation. To ensure
reliable operation of the monitor and to protect it from overheating, be sure these openings are not
blocked or covered. Do not place the monitor on a bed, sofa, rug or similar surface. Do not place the
monitor near or over a radiator or heat register. Do not place the monitor in a bookcase or cabinet
unless proper ventilation is provided.
lThe 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 supplied to your home, consult your dealer or local power company.
lThe monitor is equipped with a three-pronged grounded plug, a plug with a third (grounding) pin. This
plug will fit only into a grounded power outlet as a safety feature. If your outlet does not accommodate
the three-wire plug, have an electrician install the correct outlet, or use an adapter to ground the
appliance safely. Do not defeat the safety purpose of the grounded plug.
lUnplug the unit during a lightning storm or when it will not be used for long periods of time. This will
protect the monitor from damage due to power surges.
lDo not overload power strips and extension cords. Overloading can result in fire or electric shock.
lNever push any object into the slot on the monitor cabinet. It could short circuit parts causing a fire or
electric shock. Never spill liquids on the monitor.
lDo not attempt to service the monitor yourself; opening or removing covers can expose you to
dangerous voltages and other hazards. Please refer all servicing to qualified service personnel.
lTo ensure satisfactory operation, use the monitor only with UL listed computers which have
appropriate configured receptacles marked between 100-240V AC, Min. 3.5A.
lThe wall socket shall be installed near the equipment and shall be easily accessible.
lFor use only with the attached power adapter (output 12V DC) which have UL,CSA listed license

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SPECIAL NOTES ON LCD MONITORS
The following symptoms are normal with LCD monitor and do not indicate a problem.
NOTES
lDue to the nature of the fluorescent light, the screen may flicker during initial use. Turn off the Power
Switch and then turn it on again to make sure the flicker disappears.
lYou may find slightly uneven brightness in the screen depending on the desktop pattern you use.
lThe LCD screen has effective pixels of 99.99% or more. It may include blemishes of 0.01% or less such
as a missing pixel or a pixel lit all of the time.
lDue to the nature of the LCD screen, an afterimage of the previous screen may remain after switching
the image, when the same image is displayed for hours. In this case, the screen is recovered slowly by
changing the image or turning off the Power Switch for hours.

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Table of contents
Chapter 1 MONITOR FEATURE ………………………………………………………….9
Chapter 2 OPERATING INSTRUTION …………………………………………………….19
Chapter 3 MACHINE ASSEMBLY ………………………………………………………. .24
Chapter 4 TROUBLE SHOOTING ………………………………………………………..36
Chapter 5 CONNECTOR INFORMATION ………………………………………………39
Chapter 6 FRU LIST ………………………………………………………………………...41
Chapter 7 SCHEMATIC DIAGRAM ………………………………………………………...42
Chapter 8 POWER BOARD INFORMATION……………………………………………….48

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Chapter 1
Monitor Feature
Driving system TFT Color LCD
Size 19"
Pixel pitch 0.294 mm
Viewable angle AU panel 8ms :70/60/70/70 degree(typ)
LG panel-8ms(TLB1/TLB4):70/70/70/70 degree(typ)
Samsung-8ms:75/60/75/75 degree(typ)
CPT panel-8ms:65/65/70/70 degree(typ)
HSDpanel-8ms:TBD
Brightness LG panel-8ms(TLB1/TLB4) :300 cd/m2(typ.)
AUO 8ms:270cd/m2(typ.)
Samsung 8ms: 300 cd/m2(typ.)
CPT 8ms:250 cd/m2(typ.)
HSD 12ms:250 cd/m2(typ.)
Contrast Ratio 700:1 (AU M190EN04 V5 ,8ms)
550:1(LG LM190E03 TLB1/TLB4, 8ms)
700:1(Samsung TLM190EX-L01, 8ms)
700:1(CPT CLAA10EA05, 8ms)
600:1(HSD HSD190ME13-A02,8ms)
LCD Panel
Response time
AU (V5) 8ms,LG (TLB1/TLB4) 8ms,Samsung 8 ms, CPT
8ms,HSD 8 ms
Video R,G,B Analog,
Input Separate SyncH/V TTL
H-Frequency 31-81KHZ
V-Frequency 56-75HZ
Display Color 16.2 million Colors
Maximum Dot Clock ® 135MHz
Max Resolution 1280x1024@75HZ

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Plug & Play VESA DDC2B
ON Mode <40W
EPA ENERGY STAY OFF Mode <2W
Audio output Rated Power 2.0W rms(Per channel)
Input Connector D-Sub, DVI-D
Input Video Signal Analog : 0.7Vp-p,75OHM
Horizontal : 337.9mm
Screen Size (Active) Vertical : 270.3mm
Power Source 90~264 Vac, 47~63HZ
Environmental
Considerations
Operating Temp : 5 to 40 degree ;
Storage Temp : -20 to 60 degree ;
Operating Humidity : 10% to 85%
Weight (N.W.) TBD
Dimension TBD
Switch * Power Switch
* MENU / EXIT
* / Volume
* / Volume
* AUTO / ENTER
External Controls
* Contrast/brightness
* Focus
* Clock
* H.Position
* W.Position
* Language
* OSD Color temperature
* OSD Position & Timeout
* Auto Config
* Input
* Information
* Reset
* Exit
Regulatory Compliance cUL, FCC, TUV, CE, ISO13406-2

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Timings
The product has 26 memory modes in total. 16 modes are preset and 10 modes
are user definable.
MODE NO. 1234
RESOLUTION 720 x 400 640 x 480 640x480 640 x 480
Dot clock(MHz) 28.321 25.175 30.24 31.5
f h 31.469kHz 31.469kHz 35.0kHz 37.861kHz
H-Total ( us ) 31.78(900dots) 31.778 (800 dots) 28.571(864 dots) 26.413 (832 dots)
H-Sync ( us ) 3.813(108dots) 3.813 (96 dots) 2.116 (64 dots) 1.270(40 dots)
H-B-P ( us ) 1.907(54dots) 1.907 (48 dots) 3.175 (96 dots) 4.064(128 dots)
H-Active ( us ) 25.42(720dots) 25.422 (640 dots) 21.164 (640 dots) 20.317(640 dots)
H-F-P ( us ) 0.636(18dots) 0.636 (16 dots) 2.116 (64 dots) 0.762(24 dots)
f v 70Hz(70.087) 60Hz (59.940) 66.7 HZ (66.667)
72.809Hz
V-Total (ms ) 14.27(449 lines) 16.683 (525 lines ) 15.000 (525 lines ) 13.735(520 lines)
V-Sync ( ms ) 0.064(2 lines) 0.064 (2 lines ) 0.086 (3 lines ) 0.079(3 lines)
V-B-P (ms ) 1.112(35 lines) 1.049 (33 lines ) 1.114 (39 lines ) 0.739(28 lines)
V-Active ( ms ) 12.71(400 lines) 15.253 (480 lines ) 13.714 (480 lines ) 12.678(480 lines)
V-F-P ( ms ) 0.384(12 lines) 0.317 ( 10 lines) 0.086 (3 lines ) 0.237(9 lines)
SYNC. H/V -/+ -/ -+/+ -/-
POLARITY Or -/-
SEP . SYNC YYYY
MODE NO. 5678
RESOLUTION 640 x 480 800 x 600 800 x 600 800 x 600
Dot clock(MHz)
31.5 36 40 49.5
f h 37.500kHz 35.16kHz 37.879kHz 46.875kHz
H-Total ( us ) 26.667(840 dots) 28.44(1024 dots) 26.40 (1056
dots)
21.333 (1056dots)
H-Sync ( us ) 2.032 (64 dots) 2.00(72 dots) 3.200 (128 dots) 1.616 (80 dots)

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H-B-P ( us ) 3.810 (120 dots) 3.56(128 dots) 2.200 ( 88 dots) 3.232 (160 dots)
H-Active ( us ) 20.317 (640 dots) 22.22(800 dots) 20.00 ( 800 dots) 16.162 (800 dots)
H-F-P ( us ) 0.508 (16 dots) 0.67(24 dots) 1.000 (40 dots) 0.323 (16 dots)
f v 75Hz (75) 56.25 60Hz (60.316) 75Hz (75.000)
V-Total (ms ) 13.333 (500 lines) 17.78(625 lines) 16.58 (628 lines) 13.333 (625lines)
V-Sync ( ms ) 0.080 (3 lines) 0.06(2 lines) 0.106 (4 lines) 0.064 (3 lines)
V-B-P (ms ) 0.427 (16 lines) 0.63(22 lines) 0.607 (23 lines) 0.448 (21 lines)
V-Active ( ms ) 12.80 (480 lines) 17.07(600 lines) 15.84 (600 lines) 12.80 (600lines)
V-F-P ( ms ) 0.027 ( 1 line ) 0.03( 1 line) 0.026 (1 line ) 0.021 (1 line )
SYNC. H/V -/ -+/+ + / + + / +
POLARITY
SEP . SYNC YYYY
MODE NO. 910 11 12
RESOLUTION 800 x 600 832 x 624 1024 x 768 1024 x 768
Dot clock(MHz)
50 57.283 65 75
f h 48.077kHz 49.72kHz 48.363kHz 56.48kHz
H-Total ( us ) 20.80 (1040dots) 20.11(1152 dots) 20.677(1344 dots) 17.71(1328 dots)
H-Sync ( us ) 2.400 ( 120 dots) 1.12(64 dots) 2.092(136 dots) 1.81(136 dots)
H-B-P ( us ) 1.280 (64 dots) 3.91(224 dots) 2.462(160 dots) 1.92(144 dots)
H-Active ( us ) 16.00 (800 dots) 14.52( 832 dots ) 15.754(1024 dots) 13.65(1024 dots)
H-F-P ( us ) 1.120 (56 dots) 0.56(32 dots ) 0.369(24 dots) 0.32(24 dots)
f v 72Hz (72.188) 74.55Hz 60.004Hz 70.07Hz
V-Total (ms ) 13.85 (666 lines) 13.41(667 lines) 16.666(806 lines) 14.27(806 lines)
V-Sync ( ms ) 0.125 (6 lines) 0.06(3 lines) 0.124(6 lines) 0.11(6 lines)
V-B-P (ms ) 0.478 (23 lines) 0.78(39 lines) 0.600(29 lines) 0.51(29 lines)
V-Active ( ms ) 12.48 (600 lines) 12.55 (624 lines) 15.880(768 lines) 13.60(768 lines)
V-F-P ( ms ) 0.770 ( 37
line )
0.02(1 line) 0.062(3 lines) 0.05(3 lines)
SYNC. H/V + / + +/+ -/--/-
POLARITY
SEP . SYNC YYYY

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MODE NO. 13 14 15 16
RESOLUTION 1024 x 768 1280 x 1024 1280 x 1024 1152 x 864
Dot clock(MHz)
78.75 108 135 108
f h 60.02kHz 63.981kHz 79.976KHz 67.5 KHz
H-Total ( us ) 16.66(1312 dots) 15.630 (1688 dots) 12.504 (1688 dots) 14.815(1600 dots)
H-Sync ( us ) 1.22 (96 dots) 1.037 (112 dots) 1.067 (144 dots) 1.185(128 dots)
H-B-P ( us ) 2.23 (176 dots) 2.296 (248 dots) 1.837 (248 dots) 2.370(256 dots)
H-Active ( us ) 13.00 (1024 dots) 11.852 (1280 dots) 9.481 (1280dots) 10.667(1152 dots)
H-F-P ( us ) 0.20 (16 dots) 0.444 (48 dots) 0.119 (16 dots) 0.593(64 dots)
f v 75.03Hz 60.020Hz 75.025 Hz 75.06 Hz
V-Total (ms ) 13.33 (800 lines) 16.661 (1066
lines)
13.329 (1066
lines)
13.333(900 lines)
V-Sync ( ms ) 0.05 (3 lines) 0.047 ( 3 lines) 0.038 (3 lines) 0.044(3 lines)
V-B-P (ms ) 0.47 (28 lines) 0.594 ( 38 lines) 0.475 (38 lines) 0.474(32 lines)
V-Active ( ms ) 12.80 (768 lines) 16.005 (1024
lines)
12.804(1024 lines) 12.800(864 lines)
V-F-P ( ms ) 0.02 (1 lines) 0.016 (1 line ) 0.013 (1 lines) 0.015(1 lines)
SYNC. H/V -/-+/+ +/+ +/+
POLARITY
SEP . SYNC YYYY
A
: H-Total O
: V-Total
B : H-Sync width P : V-Sync width
C : H-Back porch Q :.V-Back porch
D : H-Video width R : V-Video width
E : H-Front porch S :.V-Front porch

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Monitor Block Diagram

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Chapter 2
OPERATING INSTRUCTIONS
Front Panel Definition
This Section defines the front panel User Interface for Led Indictor and Key function.
Key Definition:
There are five keys defined in this system and described bellows.
External Controls
?
1
POWER
Power on/off
Blue: power on
Orange: in sleep mode
?
2 OSD
Function
Press to view OSD.
Press again to exit a selection in OSD.
?
3
UP/ PLUS
If OSD is active, press to select or adjust OSD options. If OSD
is inactive, press once, then press the buttons marked or
to adjust the volume.
?
4 DOWN /
MINUS
If OSD is active, press to select or adjust OSD options. If OSD
is inactive, press once, then press the buttons marked or
to adjust the volume.
?
5
AUTO
If OSD is active, press to enter a selection in OSD. If OSD is
inactive, press and the monitor will automatically optimize the
position, focus and clock of your display.

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OSD Menu
Picture
Brightness:
This adjusts the brightness of the picture on the screen.
Contrast:
This adjusts dark and light shades of color relative to each other to
achieve a comfortable contrast.
Color temp. :
There are three ways of adjusting color:
Warm (Reddish white)
Cool (Bluish white)
User : You can adjust the colors red, green and blue to the intensity
you desire.
Focus:
This removes any horizontal distortion and makes the picture clear
and sharp.
Clock:
If there are any vertical stripes seen on the background of the screen
this renders them less noticeable by minimizing their size. It also
changes the size of the horizontal screen.
H-Position:
This adjusts the horizontal screen position.
V-Position:
This adjusts the vertical screen position.

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Option
Auto Config. :
System choose signal “Analog or Digital”
Reset:
Recall to default settings.
Information:
This shows brief information on the screen.
Setting
Language:
Select the OSD menu language from
English, French, German, Italian, Spanish, Simplified Chinese,
Traditional Chinese, Japanese and Russian.
OSD H. Position
OSD V. Position
OSD Time-out
This changes the position of the OSD window on the screen and staying
time.

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LED Definition
The system equips one dual color (blue/amber) led to indict system status and defined as bellows :
LOGO :
When the monitor is power on, the LOGO will be showed in the center, and disappear slowly.
HOW TO OPTIMIZE THE DOS-MODE
Plug and play
Plug & play DDC2B feature
This monitor is equipped with VESA DDC2B capabilities according to the VESA DDC STANDARD. It
allows the monitor to inform the host system of its identity and, depending on the level of DDC used,
communicate additional information about its display capabilities. The communication channel is defined in
two levels, DDC2B.
The DDC2B is a bi-directional data channel based on the I2C protocol. The host can request EDID
information over the DDC2B channel.
System in power-off modeDark
System in power-saving mode
Amber
System in normal operation modeGreen
System StatusLED Color