HP L1902 User manual

HP L1902 Service Manual
Page 1 of 69
-
SERVICE MANUAL
19” LCD Monitor
L1902
THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY
REASONABLE EFFORT HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE
CANNOT GUARANTEE THE ACCURACY OF THIS INFORMATION AFTER THE DATE OF
PUBLICATION AND DISCLAIMS RELIABILITY FOR CHANGES, ERRORS OR OMISSIONS.
MANUFACTURE DATA ：Feb-29-2004

HP L1902 Service Manual
Page 2 of 69
Table of Contents
Table of Contents ---------------------------------------------------------------------------------- 02
Revision List ---------------------------------------------------------------------------------------- 04
1.Product Feature ---------------------------------------------------------------------05
2 LCD Monitor Description ---------------------------------------------------------------05
3 Operation Instructions --------------------------------------------------------------------06
3.1 General Instructions ------------------------------------------------------------------06
3.2 Control Button -------------------------------------------------------------------------06
3.3 Adjusting The Picture ----------------------------------------------------------------07
4. Input/Output Specification ---------------- --------------------------------------------------- 08
4.1 Input Signal Connector ------------------------------------------------------------------08
4.1.1 Analog D-SUB Connector ----------------------------------------------------------08
4.2 Factory Preset Display Modes --------------------------------------------------------09
4.3 Power Supply Requirements ----------------------------------------------------------09
4.3.1 Input/Output Requirements ------------------------------------------------------09
4.3.2 Inverter Max Brightness -----------------------------------------------------------10
4.3.3 Inverter Min Brightness ------------------------------------------------------------10
5.Panel Specification (LG E03/AU EN04) ------------------------------------------------11
5.1 General Feature -------------------------------------------------------------------------11
5.2 Optical Characteristics ---------------------------------------------------------------12
6. Block Diagram -----------------------------------------------------------------------------------14
6.1 Monitor Exploded View ----------------------------------------------------------------14
6.2 Software Flow Chart ---------------------------------------------------------------------15

HP L1902 Service Manual
Page 3 of 69
6.3 Electrical Block Diagram ----------------------------------------------------------------16
6.3.1 Scalar Board ----------------------------------------------------------------------16
6.3.2 Inverter/Power Board -----------------------------------------------------------17
7. Schematic -----------------------------------------------------------------------------------------19
7.1 Scalar Board ----------------------------------------------------------------------------19
7.2 Inverter/Power Board --------------------------------------------------------------25
7.3 Key Pad Board -------------------------------------------------------------------------26
8. PCB Layout --------------------------------------------------------------------------------------27
8.1 Main Board -----------------------------------------------------------------------------27
8.2 Inverter/Power Board ----------------------------------------------------------------30
8.3 Keypad Board -------------------------------------------------------------------------25
9. Maintainability -----------------------------------------------------------------------------------30
9.1 Equipments and Tools Requirements ---------------------------------------------30
9.2 Trouble Shooting -----------------------------------------------------------------------31
9.2.1 Main Board ------------------------------------------------------------------31
9.2.2 Power/Inverter Board -------------------------------------------------------33
9.2.3 Key Pad Board -----------------------------------------------------------------35
10. White-Balance, Luminance Adjustment ----------------------------------------------- 36
11. EDID Content -----------------------------------------------------------------------------------37
12. BOM List ----------------------------------------------------------------------------------38～69
12.1 T980KGLHKHHPN ------------------------------------------------------38～53
12.2 T980KAXDKHHPN ------------------------------------------------------53～69

HP L1902 Service Manual
Page 4 of 69
Revision List
Revision Date Change Description
A00 May-31-04 Add Panel spec and BOM of AU Panel model

HP L1902 Service Manual
Page 5 of 69
1.PRODUCT FEATURE
48.18cm(19”) a-si TFT Active matrix LCD panel, 0.294mm dot pitch
Scalar chipset : gmZAN3SL ( or MST9111B)
Microprocessor controlled scan technology
16 factory presets, 20 new modes
Vertical refresh rate 50Hz to 75Hz; Horizontal frequency 30kHz to 83kHz
Resolutions: 640 x 480 up to 1280 x 1024
Power Internal AC100V-240V (+/-10%)
Tilt -5° to 20°
CE mark
TCO 03 mark
VESA DPMS compliant
VESA DDC2B compliant and DDC/CI interface.
2. LCD MONITOR DESCRIPTION
The LCD Monitor will contain main board, power board, key board and 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.
Power Board
Flat Panel and
CCFL backlight
Main Board
Keyboard
RS232 Connector
For white balance
adjustment in
factory mode
HOST Computer
CCFT Drive.
AC-IN
100V-240V Video signal, DDC
Monitor Block Diagram

HP L1902 Service Manual
Page 6 of 69
3. OPERATION INSTRUCTIONS
3.1 General Instructions
Press the power button to turn the monitor on or off. The other control buttons are located
at front panel of the monitor. By changing these settings, the picture can be adjusted
to your personal performance.
-The power cord should be connected and insert to adaptor.
-Connect the video cable from the monitor to the computer VGA card.
-Press the power button to turn on the monitor, the power indicator will light up to Green.
3.2 Control Buttons
-Power Button:
When pressed, the monitor enters the off mode, and the LED turns blank. Press again to restore
normal status.
-(Down/ Auto) and + (Up) Button:
The -/+ Button is browse OSD key. Press a select into adjustment.
The Auto Adjust Key is used to automatically set the H Position, V Position, Clock and Phase.
- Select Key:
Select key is into OSD sub-menu hot key when OSD turn on.
-Power Indicator:
Green — Power On mode.
Amber — Power Saving mode.
Blank — Power Off Mode.
CONTROL BUTTONS
Select Button Down / Auto Button Up Button On/Off Switch

HP L1902 Service Manual
Page 7 of 69
3.3 Adjust The Picture
1.
Brightness
Adjust the brightness.
2. Contrast Adjust the contrast
3. Image Control
Adjust the:
zAuto Adjustment: Adjusts the main settings and produces a
stable, centered image.
zH-Position: horizontal position of the screen image.
zV-Position: vertical position of the screen image.
zClock: frequency of the pixel clock to minimize vertical bar.
zPhase: phase value to minimize horizontal jitters.
3. Color
z9300K: recall 9300K color
z6500K: recall 6500K color
zSRGB: recall SRGB color
zCustom Color: adjusts the color tint of white, and the red,
green, and blue (RGB) mix for colors.
4. Language Shows the language of the OSD window.
5.
Management
zPower Saver: enable/disable power saving
zPower On Recall: enable/disable power recall
zMode Display: enable/disable mode display
zSleep Timer: set sleep timer
zBasic Menu: set to basic menu
6. OSD Control OSD (on Screen Display) settings: adjusts the H/V position,
timeout, On Screen Display window.
7. Factory Reset Resets the display to original factory settings for color, brightness,
phase, and clock.
8. Exit Exit the current OSD window.

HP L1902 Service Manual
Page 8 of 69
4. Input/Output Specification
4.1 Input Signal Connector
4.1.1 Analog D-SUB Connector
PIN MNEMONIC SIGNAL
1 RV Red Video
2 GV Green Video
3 BV Blue Video
4 NC
None
5 GND Ground (DDC Return)
6 RG Red GND
7 GG Green GND
8 BG Blue GND
9 +5 V +5 V (from PC)
10 SG Sync Ground
11 NC None
12 SDA DDC Data
13 HS Horizontal Sync
14 VS Vertical Sync
15 SCL DDC Clock
VGA connector layout
PIN 1 PIN 5
PIN 11

HP L1902 Service Manual
Page 9 of 69
4.2 Factory Preset Display Modes
Preset Pixel
Format
Horz
Freq (KHz)
Horz
Polarity
Vert Freq
(Hz)
Vert
Polarity
Pixel Clk
(MHz) Source
1 640 x 480 31.469 - 59.940 - 25.175 VGA
2 640 x 480 37.861 - 72.809 - 31.500 VESA
3 640 x 480 37.500 - 75.000 - 31.500 VESA
4 720 x 400 31.469 - 70.087 + 28.322 VGA
5 800 x 600 37.879 + 60.317 + 40.000 VESA
6 800 x 600 48.077 + 72.188 + 50.000 VESA
7 800 x 600 46.875 + 75.000 + 49.500 VESA
8 832 x 624 49.726 ± 74.551 ± 57.284 MAC
9 1024 x 768 48.363 - 60.004 - 65.000 VESA
10 1024 x 768 56.476 - 70.069 - 75.000 VESA
11 1024 x 768 60.023 + 75.029 + 78.750 VESA
12 1152 x 870 68.68 - 75.06 - 100.000 Mac
13 1152 x 900 71.71 - 76.05 - 105.561 Sun
14 1280 x 1024 63.98 + 60.02 + 108.000 VESA
15 1280 x 1024 79.97 + 75.02 + 135.000 VESA
4.3 Power Supply Requirements
4.3.1 Input / Output Requirements
PARAMETER RANGE
AC Input Voltage 90 to 264V
AC Input Frequency 47 to 63 Hz
AC Input Current 1.5A MAX
Inrush Current 60A MAX AT 264VAC COLD START
Leakage Current 3.5 mA MAX and less than 0.25mA at 100Vac
Output voltage / current 12V / 3.5A , 5V / 1.5A
Output power 45W Max
Efficiency >80%
Saving Mode <2W Max @5V/0.1A , 12V/0A

HP L1902 Service Manual
Page 10 of 69
4.3.2 Inverter Max Brightness
(Vadj:4.5v), LOAD=100KΩX4 (ROOM TEMPERATURE 25℃±4℃)
ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK
Input voltage Vin 10.8 12 13.2 V
Input current Iin 1700 1870 mA FOR 4LOAD
Output Current Iout 6 6.5 7 mA FOR 1 LOAD
Frequency F 40 50 60 KHZ FOR 1 LOAD
H.V open Vopen 1350 1550 1750 Vrms NO LOAD
H.V Load Vload 550 650 750 Vrms RL=100KΩ
Protect delay time PDT 0.4 1 4 Sec
4.3.3 Inverter Min Brightness
(Vadj:0.0v), LOAD=100KΩX4 (ROOM TEMPERATURE 25℃±4℃)
ITEM SYMBOL MIN. TYP. MAX. UNIT REMARK
input voltage Vin 10.8 12 13.2 V
input current Iin -- 500 550 mA FOR 4 LOAD
Output Current Iout 3 3.5 4 mA FOR 1 LOAD
Frequency F 40 50 60 KHZ FOR 1 LOAD
H.V open Vopen 1350 1550 1750 Vrms NO LOAD
H.V Load Vload 250 350 450 Vrms RL=100KΩ