HP LE1851w Service manual
18.5" LCD Color Monitor HP LE1851w
Service
Service
Service
Horizontal Frequency
24- 83 kHz
TABLE OF CONTENTS
Description Page Description Page
Table Of Contents.......……..............................…........1
Revision List.…........................................……......2
1. Monitor Specification..............................………........3
2. LCD Monitor Description…………………………….......4
3. Operation Instruction…………...............……..........5
3.1. General Instructions...........................…...........5
3.2. Control Button…………….…..............……...............5
3.3 Adjusting the Picture...........................…......... ..6
4. Input/Output Specification............……………...........10
4.1. Input Signal Connector............…………................10
4.2. Factory Preset Display Modes......…..................10
5. Panel Specification.....………………..................11
5.1. General Feature…….....………………..................11
5.2. Optical Characteristics………………………………11
5.3 Parameter guide line for CCFL Inverter……………..13
6. Block Diagram……...................…………................15
6.1 Software Flow Chart………………………………...15
6.2.Electrical Block Diagram……………..….......17
7. Schematic……………......................................19
7.1 Main Board....……….......................................19
7.2 Power Board.….……....................................24
7.3 Key Board…………………………………………..26
8.PCB Layout..…….................................. ........ ..... ...27
8.1. Main Board………........................................27
8.2. Power Board….......................................28
8.3. Key Board………............….......................30
9. Maintainability……….......................................31
9.1. Equipments and Tools Requirement..............31
9.2. Trouble Shooting……….............................32
9.2.1 Main Board…………..............................32
9.2.2 Power Board………..............................34
9.2.3 Key Board…………..............................36
10 White-Balance, Luminance adjustment...37
11.Mechanical Instructions……………..…...….......39
12. Monitor Exploded View………………..…....….......42
13. BOM List………………………………..……………43
14. Different Parts List.........…………..........................53
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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18.5" LCD Color Monitor HP LE1851w
Revision List
Version Date Revision History TPV Model Name
T89MM5DBRWHPNNE
Initial release
A00 Mar.-16-2009
Panel List in Item 5
T89MM5DBRWHPNCE
T89SM5DBRWHPNNE
T89SM5DBRWHPNCE
M185B1-L02
LTM185AT01 Q01 / Q02
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18.5" LCD Color Monitor HP LE1851w
1. Monitor Specification
3
18.5" LCD Color Monitor HP LE1851w
(
2. LCD Monitor Description
The LCD Monitor will contain main board, power board, a key board which house 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
CCFT Drive.
Flat Panel and
CCFL backlight
Power Board
Include adapter board)
Main Board
Keyboard
RS232 Connector
For white balance
adjustment in
factory mode
AC-IN
110V-240V
HOST Computer
Video signal, DDC
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18.5" LCD Color Monitor HP LE1851w
3. Operation Instructions
3.1 General Instructions
The monitor settings can be adjusted from the On-Screen Display (OSD) menu. To access the OSD
and adjust screen settings base on your viewing preference, do the following:
1. If the monitor is not already on, press the power button to turn on the monitor. The power indicator
will light up.
2. To access the OSD menu, press the Menu button.
3. To navigate through the Main Menu, press the – or + buttons. Once the desired function is
highlighted, press the Menu button to activate the Submenu. Press the Menu button to select the
highlighted function.
4. Press the – or + button to change the settings of the selected function. Press the – or + button to
select another function in the Submenu.
5. Press Auto/OK to select the highlighted function.
3.2 Control Button
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18.5" LCD Color Monitor HP LE1851w
3.3 Adjust the Picture
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18.5" LCD Color Monitor HP LE1851w
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18.5" LCD Color Monitor HP LE1851w
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18.5" LCD Color Monitor HP LE1851w
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18.5" LCD Color Monitor HP LE1851w
4. Input/Output Specification
4.1 Input Signal Connector
4.1.1 D-SUB connector
Pin Signal Pin Signal
1
2 Green Video 10 Logic Ground
3
4
5
6
7
8 Blue Ground
Red Video
Blue Video
NC
DDC-Return
Red Ground
Green Ground
PIN 1
PIN 11
4.2 Factory Preset Display Modes
9
11
12
13
14
15
VGA connector layout
+5V Supply
NC
DDC-Serial Data
H-Sync.
V-Sync.
DDC-Serial Clock
PIN 5
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18.5" LCD Color Monitor HP LE1851w
5. Panel Specification
5.1 General Feature
M185B1-L02
LTM185AT01 Q01/Q02
5.2 Optical Characteristics
M185B1-L02
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18.5" LCD Color Monitor HP LE1851w
LTM185AT01 Q01/Q02
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18.5" LCD Color Monitor HP LE1851w
5.3 Parameter guide line for CCFL Inverter
1.TFT LCD Module:
M185B1-L02
LTM185AT01 Q01/Q02
2. Back Light Unit:
M185B1-L02
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18.5" LCD Color Monitor HP LE1851w
LTM185AT01 Q01/Q02
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18.5" LCD Color Monitor HP LE1851w
6. Block diagram
6. 1 Software Flow Chart
1
Y
2
N
3
4
5
N
Y
6
N
7
8
Y
9
10
N
11
12
Y
13
N
N
Y
14
15
Y
N
16
Y
17
18
N
19
Y
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18.5" LCD Color Monitor HP LE1851w
REMARK:
1) MCU initialize.
2) Is the EEprom blank?
3) Program the EEprom by default values.
4) Get the PWM value of brightness from EEprom.
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 EEprom.
Turn on the LED and set it to green color.
Scalar initialize.
10) In standby mode?
11) Update the lifetime of back light.
12) Check the analog port, are they’re 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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