Lenovo L172 Schematic

17” LCD Color Monitor Lenovo L172

Service

Horizontal Frequency

30-83 kHz

TABLE OF CONTENTS

Description

Table Of Contents.......……..............................…........1

Revision List.…........................................……......2

Important Safety Notice.…….........................……......3

1.Monitor Specification..............................………........4

2.LCD Monitor Description…………………………….......5

3.Operation Instruction……………...............……...........6

3.1.General Instructions………..........................….......... .6

3.2.Control Button…………….…..............……...............6

3.3.Adjusting the Picture...........................…............7

4.Input/Output Specification............……………............9

4.1.Input Signal Connector............………….................9

4.2.Factory Preset Display Modes.........................9

N

4.3.Panel Specification.....……...……………..................10

5.Block Diagram………...................…………................12

5.1.Software Flow Chart…………………………...........12

Page Description Page

5.2.Electrical Block Diagram…………………..….......14

6.Schematic…………………...................................…16

6.1.Main Board.................................................16

6.2.Power Board....……….…....................................20

7.PCB Layout..……………….......................................22

7.1.Main Board……………........................................22

7.2.Power Board….......................................25

7.3.Key Board…………...…….....................................27

8.Maintainability…………….........................................28

8.1.Equipments and Tools Requirement...............28

8.2.Trouble Shooting…………..............................29

9.White-Balance Luminance adjustment………….....35

10.Monitor Exploded View……………………….........37

11.BOM List….....................................................39

SAFETY NOTICE ANY PERSON ATTEMPTING TO SERVICE THIS CHASSIS MUST FAMILIARIZE HIMSELF WITH THE CHASSIS AND BE AWARE OF THE NECESSARY SAFETY PRECAUTIONS TO BE USED WHEN SERVICING ELECTRONIC EQUIPMENT CONTAINING HIGH VOLTAGES.

CAUTION: USE A SEPARATE ISOLATION TRANSFOMER FOR THIS UNIT WHEN SERVICING

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17” LCD Color Monitor Lenovo L172

Revision List

Revision Date Revision History TPV Model

A00 Dec-28-06 First Version Release T76CNNHQBKH12P

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17” LCD Color Monitor Lenovo L172

Important Safety Notice

Proper service and repair is important to the safe, reliable operation of all AOC Company Equipment. The servi ce procedures recommended by AOC and described in this service manual are effective methods of performin g service operations. Some of these service operations require the use of tools specially designed for the purpose. The special tools should be used when and as recommended.

It is important to note that this manual contains various CAUTIO NS and NOTICES which should be carefully read in order to minimize the risk of personal injury to service personnel. The possibility exists that improper service methods may damage the equipment. It is also important to understand that these CAUTIONS and NOTICES ARE NOT EXHAUSTIVE. AOC could not possibly know, evaluate and advise the service trade of all conceivable ways in

undertaken any such broad evaluation. Accordingly, a servicer who uses a service procedure or tool which is not recommended by AOC mu st first satisfy himself thoroughly that neither his safety nor the safe operation of the equipment will be jeopardized by the service method selected. Hereafter throughout this manual, AOC Company will be referred to as AOC.

WARNING

Use of substitute replacement parts, which do not have the same, specifie d safet y charact erist ics may create shock, fire, or other hazards.

Under no circumstances should the original design be modified or altered without written permission from AOC. AOC assumes no liability, express or implied, arising out of any unauthorized modification of design. Servicer assumes all liability.

FOR PRODUCTS CONTAINING LASER:

DANGER-Invisible laser radiation when open AVOID DIRECT EXPOSURE TO BEAM. CAUTION-Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. CAUTION -The use of optical instruments with this product will increase eye hazard.

TO ENSURE THE CONTINUED RELIABILITY OF THIS PRODUCT, USE ONLY ORIGINAL MANUFACTURER'S REPLACEMENT PARTS, WHICH ARE LISTED WITH THEIR PART NUMBERS IN THE PARTS LIST SECTION OF THIS SERVICE MANUAL. Take care during handling the LCD module with backlight unit.

-Must mount the module using mounting holes arranged in four corners.

-Do not press on the panel, edge of the frame strongly or electric shock as this will result in damage to the screen.

-Do not scratch or press on the panel with any sharp objects, such as pencil or pen as this may result in damage to the panel.

-Protect the module from the ESD as it may damage the electronic circuit (C-MOS).

-Make certain that treatment person’s body is grounded through wristband.

-Do not leave the module in high temperature and in areas of high humidity for a long time.

-Avoid contact with water as it may a short circuit within the module.

-If the surface of panel becomes dirty, please wipe it off with a soft material. (Cleaning with a dirty or rough cloth may damage the panel.)

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17” LCD Color Monitor Lenovo L172

1. Monitor Specifications

Items Descriptions

Driving system TFT Color LCD

Type CLAA170EA07Q

Size 43.0cm (17")

LCD Panel

Pixel pitch 0.264mm(H) x 0.264mm (V)

Response time (type) 5 ms for CPT panel

Input

Power Consumption

Contrast Ratio 700:1

Dot Clock 140MHz

White Luminance 300cd/m

Max. Resolution 1280 x1024

Display Color 16.2M

Viewable angle

Sync. Type H/V TTL

H-Frequency 30kHz – 83kHz

V-Frequency 55-75Hz

ON Mode < 35W

OFF Mode <1W

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160˚ (H) 160˚ (V) (CR≥10)

Plug & Play VESA DDC2BTM

Power Source 100~240VAC,47~63Hz

Operating Temp: 10°C to 35°C

Environmental

Storage Temp: -20°C to 60°C

Considerations

Operating Humidity: 10% to 80%

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17” LCD Color Monitor Lenovo L172

(

)

2. LCD Monitor Description

The LCD monitor will contain a main board, a power board and a key board which ho use the flat panel control logic, brightness control logic and DDC. The power board will provide AC to DC Inverter voltage to drive the backlight of panel and the main board chips each voltage.

Monitor Block Diagram

Power Board

Include: adapter, inverter

AC-IN 100V-240V

CCFL Drive.

Key Board

Flat Panel and CCFL backlight

Main Board

HOST Computer

RS232 Connector For white balance adjustment in factory mode

Video signal, DDC

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17” LCD Color Monitor Lenovo L172

3. Operating Instructions

3.1 General Instructions

Press the power button to turn the monitor on or off. The control buttons are located on the right side of the monitor. By changing these settings, the picture can be adjusted to your personal preferences.

The power cord should be connected.

-

Connect the video cable from the monitor to the video card.

-

Press the power button to turn on the monitor, the power indicator will light up.

-

3.2 Control Buttons

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17” LCD Color Monitor Lenovo L172

3.3 Adjusting the Picture

OSD functions

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17” LCD Color Monitor Lenovo L172

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17” LCD Color Monitor Lenovo L172

4. Input/Output Specification

4.1 Input Signal Connector

Pin No. Description Pin No. Description

1. Red Input 9. +5VDC

2. Green Input 10. Logic GND

3. Blue Input 11. GND

4. GND 12. SDA

5. GND 13. H Sync

6. Red GND 14. V Sync

7. Green GND 15. SCL

8. Blue GND

VGA connector layout

15 6

11 15

10

4.2. Factory Preset Display Modes

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17” LCD Color Monitor Lenovo L172

4.3 Panel Specification

4.3.1 General Characteristics

CLAA170EA07P is 17.0” color TFT-LCD (Thin Film Transistor Liquid Crystal Display) module composed of LCD panel, driver ICs, control circuit and backlight. By applying 8 bit digital data, 1280×1024, 16.2M-color images are displayed on the 17.0” diagonal screen. Input power voltage is

5.0V for LCD driving.Inverter for backlight is not included in this module.

4.3.2 Display Characteristics

4.3.3 Optical Characteristics

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17” LCD Color Monitor Lenovo L172

4.3.4 Parameter guide line for CCFL Inverter

TFT LCD Module:

Back Light Unit:

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17” LCD Color Monitor Lenovo L172

5. Block Diagram

5.1 Software Flow Chat

1

2

4

5

6

7

Y

3

N

Y

N

8

Y

18

9

10

Y

N

12

Y

14

19

N

11

13

15

17

N

Y

N

16

Y

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17” LCD Color Monitor Lenovo L172

1) MCU initialize.

2) Is the EPROM blank?

3) Program the EPROM by default values.

4) Get the PWM value of brightness from EPROM.

5) Is the power key pressed?

6) Clear all global flags.

7) Are the AUTO and SELECT keys pressed?

8) Enter factory mode.

9) Save the power key status into EPROM. Turn on the LED and set it to green color. Scalar initializes.

10) In standby mode?

11) Update the lifetime of back light.

12) Check the analog port, are there any signals coming?

13) Does the scalar send out an interrupt request?

14) Wake up the scalar.

15) Are there any signals coming from analog port?

16) Display "No connection Check Signal Cable" message. And go into standby mode after the message

disappear.

17) Program the scalar to be able to show the coming mode.

18) Process the OSD display.

19) Read the keyboard. Is the power key pressed?

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17” LCD Color Monitor Lenovo L172

5.2 Electrical Block Diagram

5.2.1 Main Board

Panel Interface

(CN404)

Keypad Interface

NT68663MEFG

(CN403)

SDA SCL

(Include MCU, ADC, OSD)

(U401)

RXD

RGB

TXD

H-SYNC V-SYNC

EEPROM

AT24C16AN-10SU-2.7

(U403)

Crystal 12MHz

(X401)

D-Sub Connector

(CN405)

DB15_SDA DB15_SCL

EEPROM

AF24BC02-S1

(U405)

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17” LCD Color Monitor Lenovo L172

5.2.2 Inverter/Power Board

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