Acer AL718SG Schematic

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

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h

i

1. CAUTION: 4-6 Voltage measured must not exceed 1.5 vo
No modification of any circuit should be attempted. RMS, from any exposed metallic part to t
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
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.

AC VOLTMETER

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

0.15u
.

1500 10W

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

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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

N

L

NCN

)

)

NCN

c

k

yp,

py),

)

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

PI

1 RV Red Video

2 GV Green Video

J1

1

2
3

PHONEJACK STEREO

CN6

162738495

16 17

11

12

13

14

10

DB15HD

15

MNEMO SIGNA

Part No. QD17EL07

3 BV Blue Video

4

one

Driver bit of panel 8 bit

5 GND Ground(DDC return

Contrast ratio 450:1 t

300:1min.

6 RG Red GND

Brightness 300 cd/ m2(t

7 GG Green GND

Pixel pitch 0.264 mm

8 BG Blue GND

Response time < 20 ms (Tr+Tf

9 +5V + 5V (for DDC

View angle 75/75/65/60 degrees

Color coordinate x=0.313,y=0.329

4. CONNECTORS

4.1 AC power cord : CEE22 typed connector

4.2 Audio cable

10 SG Sync GND

11

one

12 SDA DDC Data

13 HS Horizontal Sync

14 VS Vertical Syn

15 SCL DDC Cloc

AL718 3-1

5. ELECTRICAL SPECIFICATIONS 5.4 Preset Timings

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5.1 Standard conditions

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

5.2 POWER

5.2.1 Power supply

Input voltage 90~240 Volts

Power frequency 50 / 60 Hz , +/-

Input current < 2 Arms

Inrush current < 90A

Power < 50 Watts

# mode Resolution Hz

1 IBM VGA 720 x 400 70 31.46

2 VESA 640 x 480 60 31.46

”

4 VESA 640 x 480 72 37.86

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

1

MAC 16” 832 x 624 75 49.72

1

VESA 1024 x 768 60 48.36

1

VESA 1024 x 768 70 56.48

1

VESA 1024 x 768 75 60.02

1

VESA 1152 x 864 75 67.5

1

VESA 1280 x 1024 60 63.98

(KHz

5.2.2 Power Management

1

VESA 1280 x 1024 75 79.97

State Power Indicator

On < 50Watts Green

Standby < 1 Watts Amber

5.5 Signal level and input impedance

Off < 1 Watts

5.5.1 Video Signal level
This LCD display is adjusted at the factor

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

AL718 3-2

5.6 Display Area 6. ENVIRONMENTS

Display area : 338 x 270 mm

Operation Storage and

0 ~ 40 C -20 ~ +60 C

5.7 General performance

5.7.1 Maximum pixel clock
135 MHz

5.7.2 Maximum luminance

Temperat

Humidity 5 ~ 90 % * 5 ~ 90 % *

Value 250 cd / m2 at center of the

display area ,Specified by
6500K + 8 MPCD

Conditions Display image : Full white

Brightness : Maximum
Contrast : Maximum

5.7.3 Brightness variation CE marking

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

Altitude 3000m 12000m

* 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

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.

Value CR= B / A

Conditions Contrast : Maximum

B: Full white pattern
Brightness : min
A: Full black pattern
Brightness : max

AL718 3-3

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.)

4. THEORY OF OPERATION

Gree

67

63

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

Red + 171

-

n + 1

-

Blue + 1

-

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.

AL718

4-1

GPIO0 / PWM0

GPIO1 / PW

Volume contro

GPIO3 /

No use

GPIO10

u

50 GPIO

No use

51 GPIO

NV

GPIO18

No use

GPIO19

ower, on / o

GPIO20

ute , audio disable

GPIO

GPIO

NV

Pin Number

Pin Name Pin Usage

40

41

43

44 GPIO4 / UART_DI Debug Purpose

45 GPIO5 / UART_DO Debug Purpose

49

TIMER

Key-Men

11

12

Backlight control

M1

-

-

-

-

-RAM (U4) SDA

-

-

l

208

207

206

4

204

Key-P

M

21 / IRQn LED-Green

22 / HCLK

-RAM (U11) SDA

ff control

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.

AL718

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2. Power Module

followings:

2.1 Power characteristics.

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

Brightness Voltage (Vadj)

On / Off Voltage

Audio Mute Voltage

Audio Voltage Voltage

Output Static Output Characteristics

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)

0.3(Max.) ~ 3.3Vdc (min)

High (3.3Vdc) / Low(0Vdc)

0Vdc ( Mute enable ) / 3.3Vdc ( Mute Disable )

0.4Vdc (Min.) ~ 3.3Vdc(Max)

5V /1A Output : 4.75Vdc ~ 5.1Vdc

3.3V/1A Output : 3.135Vdc ~ 3.465Vdc

2.5V/0.3A Output : 2.375Vdc ~ 2.625Vdc

2.2 Inverter output characteristics.

Rated Output kick-off Voltage 1150 ~ 2000Vrms

Rated Output Voltage Voltage 725Vrms

Rated Output Frequency 50 ~ 60Khz

Rated Output Current per tube 8mArms

2.3 Audio output characteristics.

Audio amplifier ST TDA7496

Maximum Audio Output Power 1W 2 @<3% Distortion , Speaker 1W2

Line Input Impedance 10K ohm

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

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

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