Acer AL708 User manual

ACER AL708 Lcd
WARNING A
SAFETY PRECAUTIONS B
DIMENSIONS 1
GENERAL INFORMATION 2
SPECIFICATIONS 3
THEORY OF OPERATION 4
DISASSEMBLY INSTRUCTIONS 5
CONTROL LOCATION 6
NECESSARY EQUIPMENT LIST 7
BLOCK DIAGRAM 8
CONDUCTOR VIEW 9
SCHEMATIC DIAGRAM 10
TROUBLE SHOOTING HINTS 11
REPLACEMENT PARTS LIST 12
SPARE PARTS LIST 13
L7EA (AL708)

SAFETY PRECAUTIONS
1. CAUTION: 4-6 Voltage measured must not exceed 1.5 volt
No modification of any circuit should be attempted. RMS, from any exposed metallic part to the
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 is
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
L7EA (AL708) B

1. DIMENSIONS~1 unit : mm
Front Side
Rear Side
L7EA (AL708) 1-1

1. DIMENSIONS~2 unit : mm
Base Unit
Side View
L7EA (AL708) 1-2

2. GENERAL INFORMATION
1. OUTLINE 2.8 Superior display performance
This monitor is 17" multi-scan color LCD display High contrast : 350 : 1
with the following features. High brightness : 250 cd / m2(Typical)
OSD ( on screen display ) control allows easy user Wide view angle : 140 / 100 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 TCO
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 .
17 modes are preset and 9 modes are user
definable.
2.7 Fine dot pitch
LCD panel with a fine dot pitch
( Horizontal : 0.264 mm / Vertical : 0.264 mm)
L7EA (AL708) 2

3. SPECIFICATION
1. Outline 4.2 Audio : Line-in receptacle
1.1 POWER SW, LED,UP.DN,LEFT,RIGHT,SEL
and MENU key are located on the front panel.
1.2 Video signal connector, audio line-in receptacle
and DC-IN 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 CONTRAST and BRIGHTNESS can be
directly controlled with UP / DN key.
1.5 VOLUME can be controlled with LEFT /
RIGHT key.
2. MECHANICAL SPECIFICATIONS
2.1 Dimension Height : 418 mm ( 16.5")
Width : 408 mm ( 16")
Depth : 183 mm ( 7.2")
2.2 Net Weight :5.6 kg ( 12.4 lbs)
2.3 Maximum Viewable Area : Diagonal 432 mm
(17")
3. PANEL SPECIFICATIONS
4. CONNECTORS
4.1 AC inlet : CEE22 typed connector
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
MNEMON 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. AA0170E1003
Driver bit of
p
anel 8 bit
Contrast ratio 350:1 t
yp,
Bri
g
htness 250 cd/ m2
Pixel
p
itch 0.264 mm
Res
p
onse time < 30 ms
(
Tr+Tf
)
View an
g
le 75/75/65/60
Color coordinate x=0.313
,y
=0.329
L7EA (AL708) 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 factory
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
State Power Indicator
On < 50Watts Green
Standby < 5 Watts Amber
Off < 5 Watts
Input voltage 90~240 Volts
Power frequency 50 / 60 Hz, +/-3
Input current < 0.5 A
Inrush current < 1 A
Power < 50 Watts
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
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
L7EA (AL708) 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
5.7.3 Brightness variation 7.2 EMC standards
FCC part 15,subpart B , class-B
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.
5.7.4 Contrast ratio (CR)
10. SIGNAL CABLE
Signal cable with Mini D-Sub 15P connectors at
both ends.
Length : 1.5 meter.
11. RELIABILITY
11.1 MTBF for completed unit without LCD
> 30,000 hours (demonstrated MTBF)
11.2 MTBF for LCD
The brightness is still more than 50% of the
original brightness after 25,000 hours (min.)
Operation Storage and
Shipment
Tempera
ture
0 ~ 40 C -20 ~ +60 C
Humidit 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
L7EA (AL708) 3-3

4. THEORY OF OPERATION
This section describes the function of the LCD monitor per functional block.
L7EA monitor includes MB board, audio board (option), inverter board, adapter and button board.
4.1 MB BOARD
The MB board is a four-layer, single-landed design with ground and internal planes provided. DC power
from the power adapter enter the board through DC jack. Other connectors on the board are for inverter,
audio and button board .The VGA cable is a signal cable that contains video signal, sync signal and DDC
signal from PC VGA adapter.
This system board consists of 4 functional areas : flat panel controller, flash ROM , power regulator and
LVDS transmitter.
4.1.1 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 MAX6326 (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 Numbe
r
Red + 171
Red - 170
Green + 167
Green - 166
Blue + 163
Blue - 162
L7EA (AL708) 4-1

f) Panel Power Sequencing ( PPWR, PBIAS) ( Pin 113~114)
2
0 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.
4.1.2 LVDS Transmitter DS90C383 (U1,U2)
The DS90C383 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
40 GPIO0 / PWM0 Backli
g
ht contro
l
41 GPIO1 / PWM1 Volume control
42 GPIO2 / PWM2 Ke
y
-Lef
t
43 GPIO3 / TIME
R
Ke
y
-U
p
44 GPIO4 / UART_DI Debug Purpose
45 GPIO5 / UART_DO Debug Purpose
46 GPIO6 Ke
y
-Ri
g
h
t
47 GPIO7 Ke
y
-Dow
n
39 GPIO8 / IR
Q
IN
n
LED-Oran
ge
48 GPIO9 Ke
y
-Se
l
49 GPIO10 Ke
y
-Men
u
50 GPIO11
N
o use
51 GPIO12
N
V- RAM
(
U4
)
SD
A
52 GPIO13
N
V- RAM
(
U4
)
SC
L
205 GPIO16 / HFS
n
N
V- RAM
(
U11
)
SC
L
1 GPIO17
N
o use
208 GPIO18
N
o use
207 GPIO19 Ke
y
-Power
,
on / off contro
l
206 GPIO20 Mute
,
audio disable
4 GPIO21 / IR
Qn
LED-Gree
n
204 GPIO22 / HCL
K
N
V- RAM
(
U11
)
SD
A
L7EA (AL708) 4-2

4.1.3 Power Regulator AIC1563 (U12),LT1117 (U5, U6)
The AIC1563 is a monolithic control IC containing the primary functions required for DC to DC converters.
The device consists of an internal temperature compensated reference, conparator, controlled duty cycle
oscillator with an active current sense circuit. Desired output voltage are determined by the equation
Vout = 1.25 ( 1 + R104 / R103), In this case, the output voltage are 5 Volts.
The AIC1117 is a low dropout positive adjustable regulator with minumum of 1A output current capability.
So it is well suited for 3.3 V and 2.5 V Rregulator.
U6 as a 2.5 V regulator , Desired output voltage are determined by the equation
Vout=5 x ( R53 / R53+R56)= 2.5
U5 as a 3.3 V regulator , Desired output voltage are determined by the equation
Vout=5 x ( R30 / R30+R36)= 3.3
4.2 Audio Board AN7522 (U1)
The AN7522 is a 2 channel audio power amplifier capable of delivering 2W of continuous average power
to an 8 ohms with less than 0.5% (THD) from a 12 V power supply.
An7522 can directly drive 8 ohms speaker , does not require output coupling capacitor, bootstrap capacitor
,or snubber network. Audio line-in are feed into pin 6,8 of the AN7522. The output power is controlled by
the DC voltage of pin 8 from gm2120 GPIO port.
4.3 Inverter Board
This is a specific inverter for L7E monitor backlight which converters 12 Vdc to drive four cold cathod
fluorescence tubes. Electrical specification describled as below.
INPUT Rated In
p
ut Volta
ge
12Vdc
Maximum In
p
ut Volta
g
e 11.4~12.6 Vdc
In
p
ut Curren
t
< 2A
Off state In
p
ut Powe
r
< 0.1 W
On / Off Voltage 2~3.3 for On, 0~1 for Off
OUTPUT Rated Output Strike-on Voltage 1310 Vrms
Rated Out
p
ut Volta
g
e 710 Vrms at 6 mA
Rated Out
p
ut Fre
q
uenc
y
45~60KHz
Rate Out
p
ut Current
p
er tube 6 mA
L7EA (AL708) 4-3

4.4 Adapter
This is a general purpose AC / DC adapter which converter 90~240 Vac to a stabilized DC voltage 12 V
with rated output current of 4.16A . Electrical specification describled as below.
INPUT Rated Input Voltage 90~240 Vac , 50/60 Hz
O
p
eration In
p
ut Volta
ge
90~260 Vac
,
47~63 Hz
In
p
ut Curren
t
< 1.5A
Inrush Current
(
Cold Start
)
< 100A
@
120Vac
Standb
y
In
p
ut Powe
r
< 1.5 W at 120Vac
OUTPUT Rated Output Voltage 12 Vdc
Out
p
ut Volta
g
e Re
g
ulatio
n
+ 10 / -5 %
Out
p
ut Ri
pp
le and Noise < 600 mV
p
-
p
Rate Out
p
ut Curren
t
< 4.16A
Turn-on Dela
y
< 1 Secon
d
L7EA (AL708) 4-4

5. DISASSEMBLY INSTRUCTIONS
1. Stand& rear cover removal
1) remove four large screw "1" from
the rear cover
2) remove the rear cover
3) remove four screw "2"
4) remove the stand
2. ESD cover removal
1) remove four screw "3"
2) remove the ESD cover
3. MB board removal
1) remove four screw "4"
2) remove the MB board
1
1
1
1
2
2
2
2
3
3
3
3
4
44
4
L7EA (AL708) 5-1

4. Inverter board removal
1) remove two screw "5"
2) remove the Inverter board
6. Panel module removal
1) remove four screw "6"
2) remove the Panel module
7. Panel removal
1) remove four screw "7"
2) remove the Panel
5
5
6
6
6
6
7
7
7
7
L7EA (AL708) 5-2

6. CONTROL LOCATION
Examples of on-screen operation
A. Brightness / Contrast Adjustment
Brightness. Press the △and ▽buttons to
adjust the brightness of the screen.
Maximize the life of your display by using the
lowest brightness setting you are comfortable
with.
You may need to readjust brightness after the
display is warmed up.
Contrast. Press the ＜l and l＞
buttons to adjust the contrast of the screen.
←
→
Sel
↓
Power
MENU
↑
To power on and
off the display
power status
indicator ( LED )
1)To step down
the parameter
2) volume
To increase level
of selected item
Selected or
change function
To display main
menu or off
1)To step up the
parameter
2) volume
To decrease level
of selected
L7EA (AL708) 6-1

Vertical position. Press the △and ▽buttons
to move image up and down.
Horizontal position. Press the ＜l and l＞
button to move image left and right.
The Auto function configures the vertical and
horizontal position for you.
Language. Press the ＜l and l＞buttons to
change the OSD language display setting.
L7EA (AL708) 6-2

7. NECESSARY EQUIPMENT LIST
Item
1Personal Computer with Windows 98 or above version
2Luminance Meter Minolta CA 110
3Video Gnerator : Chroma 2000,2135,2250 or equivalent
4Colour Analyzer : Minolta , Chroma or equivalent
5Watt / Power Meter
610 Times Magnifier
L7EA (AL708) 7

8. L7EA (AL708) BLOCK DIAGRAM~1 ~Video
L7EA(AL708) 8-1

8. L7EA (AL708) BLOCK DIAGRAM~2 ~Audio
L7EA(AL708) 8-2

8. L7EA (AL708) BLOCK DIAGRAM-3 ~Power
L7EA(AL708) 8-3