Acer AL718 User manual

Acer AL718 Service Guide

CONTENTS
WARNING
SAFETY PRECAUTIONS
1. DIMENSIONS
2. GENERAL INFORMATION
3. SPECIFICATIONS
4. THEORY OF OPERATION
5. EXPLORED DRAWING & DISASSEMBLY INSTRUCTIONS
6. CONTROL LOCATION
7. NECESSARY EQUIPMENT LIST
8. BLOCK DIAGRAM
9. CONDUCTOR VIEW
10. SCHEMATIC DIAGRAM
11. TROUBLE SHOOTING HINTS
12. BOM LIST
13. REPLACEMENT PARTS
14. SPARE PARTS LIST
AL718

WARNING
This service information is designed for experienced repair technicians only and is not
designd for use by the general public
It does not contain warnings or cautions to advise non-technical individuals of
potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced
professional technicians.
Any attempt to service or repair the product or products dealt within this service
information by anyone else could result in serious injury or death.
AL718 A-1

SAFETY PRECAUTIONS
1. CAUTION: 4-6 Voltage measured must not exceed 1.5 vo
l
No modification of any circuit should be attempted. RMS, from any exposed metallic part to t
h
Service work should only be performed after you ground. A leakage current tester may be
are throughly familiar with all of the following safety used in the above hot check, in which case
checks and servicing guide lines. any circuit measured must not exceed 1.0
miliamp. In the case of a measurement
2. SAFETY CHECK exceeding the 1.0 miliamp value, a rework
i
Care should be taken while servicing this LCD required to eliminate the chance of a shock
display. Because of the high voltage used in the hazard.
inverter circuit. These voltage are exposed in such
areas as the associated transfomer circuits.
3. POWER SUPPLY REQUIREMENTS
The external powr converter for this display
utilizes AC and DC cords , AC cord is
detachable , but DC cord is permanently
attached . Any attempt to replace another
adapter could result in serious problem on the
display.
4. LEAKAGE CURRENT HOT CHECK
4-1 Plug the AC cord directly into the AC outlet.
Do not use an isolation transformer during this
check.
4-2 Connect a 1500 ohm , 10 watt resistor ,
paralleled by a 0.15uF capacitor between each
metallic part and a good earth ground.
4-3 Use an AC voltmeter with 1000 ohm / volt or
more sensitivity and measure the AC voltage
across the combination 1500 ohm resistor
and 0.15uF capacitor.
4-4 Move the resistor connection to each exposed
metallic part and measure the voltage.
4-5 Reverse the polarity of the AC plug in the AC
outlet and repeat the above measurement.
To Metal Parts
V
AC VOLTMETER
1500 10W
0.15u
.
Earth Ground
AL718 B-1

1. DIMENSIONS
1.1 Front View
:
unit : mm
1.2 Real View : unit : mm
AL718
1-1

1.3 Top View : unit : mm
1.4 Side View : unit : mm
AL718
1-2

2. GENERAL INFORMATION
1. OUTLINE 2.8 Superior display performance
This monitor is 17" multi-scan color LCD display High contrast : 450 : 1(typ), 300:1 (min)
with the following features. High brightness : 300 cd / m2(Typical)
OSD ( on screen display ) control allows easy user Wide view angle : 150 / 125 degrees (H/V)
adjustment.
Power saving function, which helps saving energy , 2.9 Special function
is also one of the highlights of this model. VESA DDC2B ( Display Data Channel )
Compatible
2. FEATURES
2.1 Power Saving
Built in Power Saving function based on VESA-
DMPS standard. Power energy shall be saved
by controlling the circuit in accordance with
power saving signal from computer.
2.2 OSD (on screen display) function
OSD ( 5 Languages ) function is excellent and
new man-machine interface.
Anyone is able to set up the picture as he like
through OSD menu.
2.3 Self Test function
Self Testing picture comes out by pushing special
key in the case of no-connection with computer
or power saving operation.
This function shows if monitor is alive or not and
can be used for self aging test.
2.4 Ergonomic design
Low emission design to meet MPR II and TCO99
2.5 Multi scan with digital technology
8 bit micro controller controls the circuit
operation to meet with wide range signal of Fh=
30~81 kHz and Fv= 56~75 Hz. So VGA640x400,
VGA640x480, SVGA800x600, XGA 1024x768,
SXGA 1280x1024 mode are applicable.
2.6 Factory preset
The product has 26 memory mode in total .
16 modes are preset and 10 modes are user
definable.
2.7 Fine dot pitch
LCD panel with a fine dot pitch
( Horizontal : 0.264 mm / Vertical : 0.264 mm)
AL718 2-1

3. SPECIFICATION
1. Outline 4.2 Audio : Line-in receptacle
1.1 LED POWER SW, AUTO, MANU, LEFT
and RIGHT key are located on the front panel.
1.2 Video signal cable and audio line-in receptacle
are located on the back side of the cabinet.
1.3 OSD menu includes the following function.
CONTRAST BRIGHTNESS H.POSITION
V.POSITION COLOR-TEMPERATURE 4.3 Video signal connector 15P Mini D-Sub
CLOCK PHASE LANGUAGE connector x 1
VOLUME POWER-ON-RECALL
1.4 VOLUME can be controlled with LEFT /
RIGHT key.
2. MECHANICAL SPECIFICATIONS
2.1 Dimension Height : 393 mm ( 15.5")
Width : 375 mm ( 14.8")
Depth : 182 mm ( 7.2")
2.2 Net Weight :4.24kg ( 9.35 lbs)
2.3 Maximum Viewable Area : Diagonal 432 mm
(17")
3. PANEL SPECIFICATIONS
4. CONNECTORS
4.1 AC power cord : CEE22 typed connector
4.2 Audio cable
CN6
DB15HD
1 6 2 7 3 8 4 9 5
11 12 13 14 15
10
16 17
J1
PHONEJACK STEREO
1
2
3
PI
N
MNEMO SIGNA
L
1 RV Red Video
2 GV Green Video
3 BV Blue Video
4
N
C
N
one
5 GND Ground
(
DDC return
)
6 RG Red GND
7 GG Green GND
8 BG Blue GND
9 +5V + 5V
(
for DDC
)
10 SG S
y
nc GND
11
N
C
N
one
12 SDA DDC Data
13 HS Horizontal S
y
nc
14 VS Vertical S
y
n
c
15 SCL DDC Cloc
k
Part No.
Q
D17EL07
Driver bit of
p
anel 8 bit
Contrast ratio 450:1 t
yp,
300:1min.
Bri
g
htness 300 cd/ m2
(
t
py),
Pixel
p
itch 0.264 mm
Res
p
onse time < 20 ms
(
Tr+Tf
)
View an
g
le 75/75/65/60 de
g
rees
Color coordinate x=0.313
,y
=0.329
AL718 3-1

5. ELECTRICAL SPECIFICATIONS 5.4 Preset Timings
5.1 Standard conditions
5.2 POWER
5.2.1 Power supply
5.2.2 Power Management
5.5 Signal level and input impedance
5.5.1 Video Signal level
This LCD display is adjusted at the factor
y
5.3 Acceptable timing using 0,7 Vp-p Video signal.
If your timing is within following specification, 5.5.2 Sync Signal level
this LCD display can automatically function with H/V Separate : TTL level
a certain position. 5.5.3 Input impedance
Horizontal: Sync frequency : 30~81 kHz Video input : 75 ohms
Vertical : Sync frequency : 56~75Hz Sync input : > 1 k ohms
Display area 338 x 270 mm
Video signal level 0.7 Vpp
Contrast Max.
Brightness Max.
Ambient 20 +/- 5 C degrees
Input voltage AC 120,60Hz
Warming up time > 30 minutes
Display mode 1280 x 1024
State Power Indicator
On < 50Watts Green
Standby < 1 Watts Amber
Off < 1 Watts
Input voltage 90~240 Volts
Power frequency 50 / 60 Hz , +/-
Input current < 2 Arms
Inrush current < 90A
Power < 50 Watts
Fv
Fh
# mode Resolution Hz (KHz
1 IBM VGA 720 x 400 70 31.46
2 VESA 640 x 480 60 31.46
3
MAC 13
”
640 x 480
67
35
4 VESA 640 x 480 72 37.86
5
VESA
640 x 480
75
37 5
6 VESA 800 x 600 56 35.16
7 VESA 800 x 600 60 37.87
8 VESA 800 x 600 72 48.07
9 VESA 800 x 600 75 46.87
1MAC 16” 832 x 624 75 49.72
1VESA 1024 x 768 60 48.36
1VESA 1024 x 768 70 56.48
1VESA 1024 x 768 75 60.02
1VESA 1152 x 864 75 67.5
1VESA 1280 x 1024 60 63.98
1VESA 1280 x 1024 75 79.97
AL718 3-2

5.6 Display Area 6. ENVIRONMENTS
Display area : 338 x 270 mm
5.7 General performance
5.7.1 Maximum pixel clock
135 MHz
5.7.2 Maximum luminance
* Non-condensation
7. REGULATORY STANDARDS
7.1 Safety standards
This monitor applies to various safty & EMI
standards May refer to the logo label
7.2 EMC standards
FCC part 15,subpart B , class-B
5.7.3 Brightness variation CE marking
8. OTHERS
TUV (Rheinland)
ISO13406-II pixel fault class 2
TCO99
9. P0WER CORD
Northern Hemisphere Version : UL / CSA
approved power cord.
European : VDE approved power cord.
10. SIGNAL CABLE
5.7.4 Contrast ratio (CR) Signal cable with Mini D-Sub 15P connectors
at both ends.
Length : 1.8 meter.
11. RELIABILITY
11.1 MTBF for completed unit without LCD
> 50,000 hours (demonstrated MTBF)
11.2 MTBF for LCD
The brightness is still more than 50% of the
original brightness after 30,000 hours (min.)
Operation Storage and
Shipment
Temperat
ure
0 ~ 40 C -20 ~ +60 C
Humidity 5 ~ 90 % * 5 ~ 90 % *
Altitude 3000m 12000m
Value 250 cd / m2 at center of the
display area ,Specified by
6500K + 8 MPCD
Conditions Display image : Full white
Brightness : Maximum
Contrast : Maximum
Value 75 % Variation = C / A x 100
Conditions Display image: Full white
Brightness : Maximum
Contrast : Maximum
A: Luminance at center position
C: Luminance at position of
lowest brightness
Value CR= B / A
Conditions Contrast : Maximum
B: Full white pattern
Brightness : min
A: Full black pattern
Brightness : max
AL718 3-3

4. THEORY OF OPERATION
This section describes the function of the LCD monitor per functional block.
button board.
1. MB BOARD
The MB board is a four-layer, single-landed design with ground and internal planes provided.
The VGA cable is a signal cable that contains video signal, sync signal and DDCsignal from PC VGA adapter.
This system board consists of 3 functional areas : flat panel controller, flash ROM and LVDS transmitter.
1.1 Flat panel controller…… gm2120 (U8)
The heart of the system board is Genesis gm2120. The gm2120 is a graphics processing IC for LCD
monitor. It provides all key IC functions required for LCD panel. On-chip functions include a
high-speed triple-ADC , PLL, high sacling engine, OSD controller and on-chip microcontroller.
a) Clock Generation :
Crystal Input Clock (TCLK and XTAL). This is the input pair to an internal crystal oscillator and
corresponding logic. A 14.318 MHz crystal is recommended.
b) Hardware Reset ( Pin 5 )
Hardware Reset signal is generated by MAX809 (U10).It assert a reset signal at least 100 ms.
c) Analog to Digital Converter
The gm2120 chip has three ADC's (analog-to-digital converters), one for each color (red, green and blue)
The analog RGB signals are connected to gm2120 as described below
d) OSD :
The gm2120 has a fully programmable ,high-quality OSD controller.The on-chip static RAM(4096 words
by 24 bits) stores the cell map and the cell definitions.
e) On-Chip Microcontroller (OCM)
The gm2120 on-chip microcontroller(OCM) serves as the system microcontroller.That is , it programs the
gm2120 and manages other devices in the system such as the keypad, the backlight, LED, audio and
non-volatile RAM.using general purpose input/output (GPIO) pins.
Pin Name
Pin Number
R
ed
+ 1
7
1
Red
-
170
G
r
ee
n + 1
67
Green
-
166
Bl
ue
+ 1
63
Blue
-
162
AL718
4-1

f) Panel Power Sequencing ( PPWR, PBIAS) ( Pin 113~114)
The gm2120 has two dedicated outputs PPWR and PBIAS ( Pin113 and Pin114) to control LCD power
sequencing once data and control signals are stable.
g) Parallel ROM Interface Port (Pin 8~25, Pin28~35)
The gm2120 has parallel ROM interface port , pin8~25 for address bus, pin28~35 for data bus.
h) Panel interface (Pin 55~66, Pin69~80, Pin83~87, Pin90~96.Pin99~110)
The gm2120 driver interface is highly programmable. It supports dual bus / dual port for SXGA drivers.
1.2 LVDS Transmitter DS90FC383 (U1,U2)
The DS90FC383 transmitter converts 28 bits of TTL data into four LVDS ( Low Voltage Differential
Signaling) data streams. A phase-locked transmit clock is transmitted in parallel with the data streams
over a fifth LVDS link. At a transmit clock frequency of 85 MHz, 24 bits of RGB data and 3 bits of LCD
timing and control data ( FPLINE, FPFRAME, DRDY) are transmitted at rate of 595 Mbps per LVDS
data channel. U1 AS the ODD pixel transmitter , U2 as the EVEN pixel transmitter.
Pin Number Pin Name Pin Usage
4
0
G
PI
O0
/
P
W
M
0
B
ac
kli
g
h
t
co
n
t
r
o
l
41
G
PI
O
1
/
P
W
M1
Vo
l
u
m
e
co
n
t
r
o
l
42
GPIO2 / PWM2
Key
-
Left
4
3
G
PI
O3
/
TIMER
No
use
44 GPIO4 / UART_DI Debug Purpose
45 GPIO5 / UART_DO Debug Purpose
46
GPIO6
Key
-
Right
47
GPIO7
No use
39
GPIO8 / IRQINn
LED
-
Orange
48
GPIO9
Key
-
Sel
4
9
G
PI
O
1
0
K
ey
-M
e
n
u
50
G
PI
O
11
No
use
5
1
G
PI
O
12
NV
-RAM
(U
4
)
S
DA
52
GPIO13
NV
-
RAM (U4) SCL
205
GPIO16 / HFSn
NV
-
RAM (U11) SCL
1
GPIO17
No use
2
08
G
PI
O
1
8
No
use
2
07
G
PI
O
1
9
K
ey
-P
owe
r
,
o
n
/
o
ff
co
ntr
o
l
2
06
G
PI
O
2
0
M
ute
,
aud
i
o
d
i
sab
l
e
4
G
PI
O
21
/
IR
Q
n LED-
G
r
ee
n
2
0
4
G
PI
O
22
/
H
C
LK
NV
-RAM
(U
11
)
S
DA
AL718
4-2

2. Power Module
followings:
2.1 Power characteristics.
2.2 Inverter output characteristics.
2.3 Audio output characteristics.
2.4 Power module of connector definition ;
CN1 ; Pin 1 & 2 ----> Vdc Output ( 5V +/- 5%)
Pin 3 ---------> Vdc Output ( 3.3V +/- 5%)
Pin 4 ---------> GND
Pin 5 ---------> Vdc Output ( 2.5V +/- 5%)
Pin 6 ---------> GND
Pin 7 ---------> On /Off ( "High" set Lamp on )
Pin 8 ---------> NA
Pin 9 ---------> Brightness Voltage
Pin 10 --------> Audio Volume
Input Rated Input Voltage 90~240 Vac , 50/60 Hz
Operation Input Voltage Range 90~260 Vac, 47~63 Hz
Max Input AC Current < 1.5A
Efficiency
5Vdc load 1A
3.3Vdc load 1A
2.5Vdc load 0.3A
Brightness Voltage from 0.3 ~ 3.3Vdc
ON / OFF Voltage : High(3.3Vdc)/ Low(0Vdc)
Brightness Voltage (Vadj)
0.3(Max.) ~ 3.3Vdc (min)
On / Off Voltage
High (3.3Vdc) / Low(0Vdc)
Audio Mute Voltage
0Vdc ( Mute enable ) / 3.3Vdc ( Mute Disable )
Audio Voltage Voltage
0.4Vdc (Min.) ~ 3.3Vdc(Max)
Output Static Output Characteristics
5V /1A Output : 4.75Vdc ~ 5.1Vdc
3.3V/1A Output : 3.135Vdc ~ 3.465Vdc
2.5V/0.3A Output : 2.375Vdc ~ 2.625Vdc
Rated Output kick-off Voltage 1150 ~ 2000Vrms
Rated Output Voltage Voltage 725Vrms
Rated Output Frequency 50 ~ 60Khz
Rated Output Current per tube 8mArms
Audio amplifier ST TDA7496
Maximum Audio Output Power 1W 2 @<3% Distortion , Speaker 1W2
Line Input Impedance 10K ohm
AL718
4-3

Pin 11 --------> Audio Mute
CN2 ; Pin 1 ---------> Speaker left1
Pin 2 ---------> Speaker left2
Pin 3 ---------> Speaker right1
Pin 4 ---------> Speaker right2
CN201 ~ CN204 ; Pin 1 ---------> HV ( High Voltage for CCFL )
Pin 2 ---------> Return ( Low Voltage for CCFL )
AL718
4-4

5. EXPLORED DRAWING & DISASSEMBLY INSTRUCTION
S
5.1 EXPLORED DRAWING
AL718 5-1

5.2 Disassembly
5.2.1 Stand base& rear cover removal
1.remove the two screws "1"from neck
2.remove the base
3. remove the real cover
5.2.2. PCB holder removal
1.slide the pcb holder from the panel model
2.remove the pcb holder
AL718 5-2

5.2.3. Panel module removal
1) remove four screws "4,5"
2) remove the Panel module
AL718 5-3

6. CONTROL LOCATION
6.1 Front Panel Definition
This Section defines the front panel User Interface for Led Indictor and Key function.
6.1.1 Key Definition
There are seven keys defined in this system and described bellows.
6.1.2 LED Definition
The system equips one dual color (green/amber) led to indict system status and defined
as bellows:
6.2 OSD Menu Definition
There are some OSD menus defined in this system
♦Main Menu
♦Volume menu
♦Prompt menu
More detail descriptions are listed bellows:
6.2.1 Main Menu
There are 5 sub functions in main menu. The selected function icon will show in red in
Power on/off (Soft Power)Power
In menu operation, change the selected item or decrease adjusted value
If audio exist, decrease volume level
_
In menu operation, change the selected item or increase adjusted value
If audio exist, increase volume level
+
Select/Escape the sub menu or enter item adjusting
A
uto configuration hot-key when OSD-Off
If audio exist, toggle mute on/off when volume scroll bar appear.
Select
A
ctive main menu when OSD-Off
Turn OSD off when OSD-On
Menu
FunctionName
System in power-off modeDark
System in power-saving mode
A
mber
System in normal operation modeGreen
System StatusLED Color
AL718 6-1

by press + or -Key and press Select key to enter the sub function.
* Brightness/Contrast Function
* Tracking Function
* Position Function
* Color Function
* Other Function
Selec
Selec
Selec
Selec
AL718 6-2

6.2.2 Volume Menu
6.2.3 Prompt menu
There are several prompt menu list here.
6.3 Menu Navigation
6.3.1 Main Menu Operation
The system defines a consistent key operation idea. Use + or -button to change the
item to be adjusted and the Select to confirm the selection and + or –are used to
ad
j
ust the value. The Menu ke
y
will act as
q
uit and back to OSD off durin
g
the main
Step 1:
The Menu button can back to OSD-ON
To use + or – button to select the Brightness/Contrast, Tracking, Position, Color and Othe
r
The Select button can enter function adjustment and goto next step.
The Menu button can back to OSD-OFF.
Step 2:
To use + or – button to select the item to be adjusted.
Selec
N
o Signal Out of Frequency
Auto Configuration Mode Information
AL718 6-3