HP L1940 User manual

Horizontal frequencies
30-83kHz
Service
Service
Service
TABLE OF CONTENTS
Published by BCU Monitors Printed in Suzhou Copyright reserved Subject to modification K Oct. 15 2004
Description Page
Important Safety Notice---- ------------------------------ 2
Technical Data ------------------------------------------3~4
Warning Message------------------------------------------7
Lock/unlock,Aging,Service/Factory mode------------8
Definition of pixel defects-------------------------------12
Instalation/On Screen Display------------------------5~6
Flat panel adjust--------------------------------------------9
Mechanical Instructions----------------------------10~11
Electrical instruction--------------------------------13~14
DDC Instructions-------------------------------------15~21
Failure mode of panel------------------------------------22
Safety Test Requirments--------------------------------23
ISP CABLE FOR CPU-------------------------------24~26
Description Page
Repair tips ------------------------------------------------27
Color adjustment----------------------------------------28
Repair Flow chart/Trouble shooting-------------29~32
Block Diagram---------------------------------------33~34
Control Diagram & C.B.A.------------------------------43
Power Diagram & C.B.A.--------------------------44~47
Exploded View------------------------------------------- 48
Spare/recommended parts list------------------49~50
General product specification--------------------51~78
DDC DATA -------------------------------------------79~80
Different parts list----------------------------------------81
Scaler Diagram&C.B.A.---------------------------36~42
Wiring Diagram -----------------------------------------35
REFER TO BACK COVER FOR IMPORTANT SAFETY GUIDELINES
CAUTION: USE A SEPARATE ISOLATION TRANSFORMER FOR THIS UNIT WHEN SERVICING.
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.
SAFETY NOTICE
SH4 HP L1940
GB 3138 106 10428
19" LCD Colour Monitor
EJ6B50/02
EJ6B50/69
EJ6B50/76

Important Safety Notice
2HP L1940
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Proper service and repair isimportant to the safe, reliable
operation of all HPConsumer Electronics Company**
Equipment. The service procedures recommended by HP and
described in this service manual are effective methods of
performing service operations. Some ofthese 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
CAUTIONS 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. HP could not possibly know, evaluate and
advise the service trade of all conceivable ways in which
service might be done or of the possible hazardous
consequences of each way. Consequently, HP has not
undertaken any such broad evaluation. Accordingly, a
servicer who uses a service procedure or tool which is not
recommended by HP must 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, HP Consumer
Electronics Company will bereferred to as HP.
Critical components having special safety characteristics are
identified with a bythe Ref. No. inthe parts list and
enclosed within a broken line*
(where several critical components are grouped in one area)
along with the safety symbol on the schematics or
exploded views.
Use of substitute replacement parts which do not have the
same specified safety characteristics may create shock, fire,
or other hazards.
Under no circumstances should the original design be
modified or altered without written permission from Philips.
Philips assumes no liability, express or implied, arising out of
any unauthorized modification of design.
Servicer assumes all liability.
* Broken Line
WARNING
Take care during handling the LCD module with backlight
unit
- Must mount the moduleusing mounting holes arranged infour
corners.
- Do not press onthe panel, edge of theframe strongly or electric
shock as this will result in damage to the screen.
- Do not scratch orpress on the panel withany sharp objects, such
as pencil or pen asthis may result in damage to the panel.
- Protect the module fromthe ESD as it maydamage the electronic
circuit (C-MOS).
- Make certain that treatment person s body are grounded through
wrist band.
- Do not leave themodule in high temperature andin areas of high
humidity for a long time.
- Avoid contact with water as it may ashort circuit within the module.
- If the surface ofpanel become dirty, please wipe it off with a soft
material. (Cleaning with a dirty or rough cloth may damage the
panel.)
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.

3
Technical Data
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HP L1940
Pin Assignment
InputDVI-D connector pin
LCDPanel
Type NR. :LM190E02_A5 (LPL)
Numberof Pixels. : 1280 (H) x 1024 (V)
Physical Size. : 404.2(H)*330.0(V)*20.0(D)mm
Pixel Pitch. : 0.294 x 0.294 mm
Color pixel arrangement. : RGB stripes arrangement
SupportColor. : 8 bit (16.7M Colors)
Display Mode. : Transmissive Mode,Normally Black
Backlight. : CCFL edge light system
Active area. (WxH). : 376.32(H) x 301.056(V)mm (19 diagonal)
Viewing Angle. : Vertical 176 degree, Horizontal 176 degree
(CR=10)
Contrast ratio. : 500:1
Luminance. : 250 cd/m2(Typ)
Scanning frequencies
H-Frequency. : 30K -83 K Hz
V-Frequency. : 56 -76 Hz
Powerinput. : 90-265 VAC, 50/60 ±2Hz
Powerinput. : 90-265 VAC, 50/60 ±2Hz
The inputsignalscan be applied in twodifferent modes:
1). VESA Analog
The videoinputconsists ofred, green, and blue signals. The video
signals areanalog levels, where0Vcorr
esponds toblack and 700mVis
the maximumsignalamplitude. Inputimpedanceofvideopinsis75ohm
+-1%. The VESA VSISspecification states the videovoltages shall be
700 mV+10%/-5% with 12% for the overshoot. The apability of sync
signal inputs shall include separate sync.inputimpedance: 2k2 ohms The
signals are defined as follow:
Separate sync3.3Vand5volt TTL level ,Positive/Negative
2). Intel DVI Digital
Inputsignal:Four channel TMDS signals. The digital interfaceshall
be comprised of2electrical layercomponent: a TMDSinterfacefor low-
voltage differential serial encoding of the digital display data(Panel Link
compliant) and a DDC2B electrical interface. Refertothe Digital Display
Working Group(DDWG) document, Digital Visual Interface(DVI)
Specification, Revision1.0 for the exactrequirements.
Unit dimension / Weight
Set dimension(incl. pedestal) : 413(W) * 477(H) * 265(D)mm
Net weight. : 8.4 kg
Tilt and swivel base
Basicbase: tilt angle : -5°to+35 °(operation)
swivel rotation:±90°
Shipping dimension/Weight
Carton dimension. : 524(W) * 239(D) * 513(H) mm
Gross weight. : 10 Kg
Susceptibility ofdisplay toexternal environment
Temperature Ranges
Operating Temperature(Independent of altitude) : 5°Ct
o35°C.
Non-Operating Temperature(Independent of altitude) : -20°Cto60°C.
Humidity
Operating (non-condensing) : 20% to80%
Non-Operating (38.7°Cmaximumwetbulb temperature) : 5% to90%
Altitude
Operating 0 to12,000 feet [3,658 m].Equivalent to14.7 to10.1 psia.
Non-Operating0to40,000 feet [12,192 m]. Equivalent to14.7 to4.4 psia
Red videoinput
Green videoinput
Blue videoinput
GND
Cable detect
Red videoGND
Green videoGND
Blue videoGND
DDC +3.3VOR +5V
GND
GND
Serial data line (SDA)
H-sync
V-sync
Data clock line (SCL)
7
8
6
5
4
3
2
19
10
11
12
13
14
15
Pin No.Pin No. Assignment Assignment
Pin No.Description
1T.M.D.S data2-
2T.M.D.S data2+
3T.M.D.S data2 shield
4Noconnect
5Noconnect
6DDCclock
7DDCdata
8Noconnect
9T.M.D.S data1-
10 T.M.D.S data1+
11 T.M.D.S data1 shield
12 Noconnect
13 Noconnect
14 +5Vpower
15 Ground (for +3.3V)-Cable detect
16 Hotplug detect
17 T.M.D.S data0-
18 T.M.D.S data0+
19 T.M.D.S data0 shield
20 Noconnect
21 Noconnect
22 T.M.D.S clockshield
23 T.M.D.S clock+
24 T.M.D.S clock-

Technical Data(Continued)
4
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This monitor is ENERGY STAR compliant.
this product meets the ENERGY STAR guidelines for energy
Data Storage R
R
Efficiency
ENERGY STAR is a U.S. registered mark. AS AN ENERGY STAR
PARTNER, DELL Computer Corporation HAS DETERMINED THAT
THIS PRODUCT MEETS THE ENERGY STAR GUIDELINES FOR
ENERGY EFFICIENCY.
R
HP L1940
Power management
The power consumption and the status indication of the set with power management function
are as follows,
STATUS H-sync V-sync Video Power LED indicator
On On On Active < 70W Green LCD
(*Note1)
Stand-by Off On Blanked < 2W
Amber LCD
(*Note2)
Suspend On Off Blanked < 2W
Amber LCD
(*Note2)
Off Off Off Blanked < 2W Amber LCD
(*Note2)
DC Switch off N/A N/A N / A < 1W Off (*Note 2)
Note 1: Included two active external USB devices
Note 2: Measurement is required to connect PC via USB 2.0 upstream cable and be
without any external USB devices. The operating system is required to be
Windows XP , and USB interface of PC shall conform to USB 2.0 compliance.
Display identification
Analog DDC
In accordance with VESA Display Channel Standard V1.0 and having DDC-2B capability.
Digital DDC
In accordance with DVI requirement (DDWG digital Visual Interface revision 1.0) use DDC-2B
and EDID 3.0 structure 2.0
Factory preset modes (15 modes)
# Resolution H-Frequency
(Hz)
Pixel rate
(MHz)
V-Frequency
(Hz)
Comment
1 640X480 31.469K 25.175 59.940 VGA
2 640X480 37.861K 31.5 72.809 VESA
3 640X480 37.5K 31.501 75 VESA
4 720X400 31.469K 28.322 70.087 VGA
5 800X600 37.879K 40 60.317 VESA
6 800X600 48.077K 50 72.188Hz VESA
7 800X600 46.875K 49.498 75Hz VESA
8 832X624 49.726K 57.284 74.551Hz MAC
9 1024X768 48.363K 65 60.004Hz VESA
10 1024X768 56.476K 75 70.069Hz VESA
11 1024X768 60.023K 78.75 75.029Hz VESA
12 1152X870 68.68K 100 75.06Hz MAC
13 1152X900 71.71K 108 76.05Hz SUN
14 1280X1024 63.98K 108 60.02Hz VESA
15 1280X1024 79.97K 135 75.02Hz VESA

Installation 5
HP L1940
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Connecting to PC
When two computers are connected, you will need to set the
Video Input Select on the on-screen display (OSD) menu to
specify which monitor input has priority.
1. Place the monitor in a convenient, well-ventilated location
Near your computer.
2. Connect the monitor signal cable into the correct video
connector (VGA or DVI-D) on the back of the monitor and into
the corresponding video connector on the rear panel of the
computer.
Your computer must have a DVI -compatible graphics card
installed for use with the DVI-D cable. When connecting the
DVI-D signal cable to the DVI connector on the monitor, connect
the other end of the DVI-D cable to the DVI connector on the
Computer.
3. Connect one end of the power cable to the back of the monitor,
and the other end to an electrical wall outlet.
Warnning:To reduce the risk of electric shock or damage to
your equipment:
1. Do not disable the power cord grounding plug. The grounding
plug is an important safety feature.
2. Plug the power cord into a grounded (earthed) electrical outlet
that is easily accessible at all times.
3. Disconnect power from the monitor by unplugging the power
cord from the electrical outlet.
Front control panel
Identifying Rear Panel Components
1234 5
No. Component Function
AC power
connector
Connects the AC power cord to the monitor.
USB downstream
connectors
Connects optional USB devices to the monitor.
USB upstream Connects the USB cable to the host (computer
connector or another USB hub).
DVI connector
(available on
select models)
Connects the DVI-D signal cable to the monitor.
VGA connector Connects the VGA cable to the monitor.
1
2
3
4
5
4. Do not place anything on power cords or cables. Arrange them
so that no one may accidentally step on or trip over them. Do not
pull on a cord or cable. When unplugging from the electrical
outlet, grasp the cord by the plug.
12345
No. Component Function
1
2
3
4
5
Auto Adjust Activates the auto adjustment feature for
optimum image.
Menu Opens the On-Screen Display (OSD) menu.
-(Minus) If OSD is on, press to navigate backward
through the OSD menu features and
decrease adjustment levels.
If OSD is off, press to enable the DVI
signal input(available on select models)
+ (Plus) If OSD is on, press to navigate forward
through the OSD menu features and increase
adjustment levels.
If OSD is off, press to enable the VGA signal
input.
Power Turns the monitor on or off.

On Screen Display
6
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HP L1940
Advanced osd service mode configuration
Analog Mode Menu
Menu Level 1 Menu Level 2
Brightness ADJ Scale
Contrast ADJ Scale
Auto Adjustment (Adjusting message)
Advanced Menu
Exit
Digital Mode Menu
Menu Level 1 Menu Level 2
Brightness ADJ Scale
Contrast ADJ Scale
Advanced Menu
Exit
Analog Mode Menu
Menu Level 1 Menu Level 2 Menu Level 3 Factory Reset?
Brightness ADJ Scale Y (FP=90)
Contrast ADJ Scale Y (FD=80)
Image Control Auto Adjustment (Adjusting
message)
Y(noFD)
Horizontal Position ADJ Scale Y (no FD)
Vertical Position ADJ Scale Y (no FD)
Clock ADJ Scale Y (no FD)
Clock Phase ADJ Scale Y (no FD)
Cancel
Save and Return
Color 9300 K
6500 K Y(FD)
Custom Color Custom Color
ADJ
sRGB
Cancel
Save and Return
Service Display Hours N
Reset Total Hours Confirm Reset N
Reset Backlight Hours Confirm Reset N
Copy All Settings Confirm Reset N
Recall All Settings Confirm Reset N
Display White Block N
Unlock EDID Write
Cancel N
Save and Return N
Management Power Saver On / Off
Selection
N(FD=ON)
Power On Recall On / Off
Selection
N(FD=ON)
Mode Display On / Off
Selection
N (FD=OFF)
Power-On Status
Display
On / Off
Selection
N(FD=ON)
Sleep Timer Timer Set Menu N (FD=0;OFF)
Default Video Input -Analog - VGA N(FD=DVI)
-Digital - DVI
Serial Number Display monitor
s/n
Basic Menu N(FD=Basic)
Cancel
Save and Return
OSD Control Horizontal OSD Position ADJ Scale N (FD=50)
Vertical OSD Position ADJ Scale N (FD=50)
OSD Timeout ADJ Scale N (FD=30)
Cancel
Save and Return
Information Current Settings:
Recommended Settings:
Serial Number:
Total Hours:
Backlight Hours:
Exit
Factory Reset Yes
No
Exit
Digital Mode Menu
Menu Level 1 Menu Level 2 Menu Level 3 Factory Reset?
Brightness ADJ Scale Y (FP=90)
Contrast ADJ Scale Y (FD=80)
Color 9300 K
6500 K Y(FD)
Custom Color Custom Color
ADJ
sRGB
Cancel
Save and Return
Service Display Hours
Reset Total Hours Confirm Reset N
Reset Backlight Hours Confirm Reset N
Copy All Settings Confirm Reset N
Recall All Settings Confirm Reset N
Display White Block N
Unlock EDID Write
Cancel
Save and Return
Management Power Saver On / Off
Selection
N(FD=ON)
Power On Recall On / Off
Selection
N(FD=ON)
Mode Display On / Off
Selection
N(FD=OFF)
Power-On Status
Display
On / Off
Selection
N(FD=ON)
Sleep Timer Timer Set Menu N (FD=0;OFF)
Default Video Input -Analog - VGA N (FD = DVI)
-Digital - DVI
Serial Number Display monitor
s/n
Basic Menu N(FD=Basic)
Cancel
Save and Return
OSD Control Horizontal OSD Position ADJ Scale N (FD=50)
Vertical OSD Position ADJ Scale N (FD=50)
OSD Timeout ADJ Scale N (FD=30)
Cancel
Save and Return
Information Current Settings:
Recommended Settings:
Serial Number:
Total Hours:
Backlight Hours:
Exit
Factory Reset Yes
No
Exit
basic osd menu levels

Warning Message
7
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HP L1940
Warning Message Table
Item Attention Signals Display Time Condition
1 Input Signal out of Range See power savertable
2 No Input Signal See power savertable
3 Going to Sleep See power savertable
4 Adjusting...... Auto key or OSD menu function
5 OSD Lock out 3secs Push menu key for 10 sec then display 3 sec WM OSD
Lock out
6
7 Status AC/DC on and "Power-On Status Display is on
Check Video Cable
10secs
See power savertable
Power Saver Table
Power Saver - On Power Saver - Off Note
Quit signal with
cable
1. System blank and show WM
"Going to Sleep" 3 sec then sleep.
1. System blank and show moving
WM "No Input Signal"always.
Disconnect cable 1. System blank and show WM
"Check Video Cable"60 sec.
1. System blank and show WM
"Check Video Cable" 10
2.Show WM "Going to Sleep" 3 sec
then sleep.
then repeat item 1 to 2.
sec then moving always.
Out of range - 1 1. System blank and show WM
"Check Video Cable" 20 sec then
moving about 30 sec After moving
3. If push any key in sleep mode,
then repeat item 1to 2.
1. System blank and show moving
WM"In Put Signal out of Range"
always.
H<29.5 or
H>92 or
90>H>82.5 or
V<49 or V>87
or Vtotal>=120
0
Out of range - 2 1. Show moving WM"Input Signal
out of Range" always. 85Hz
3. If push any key in sleep mode,
WM 50 sec.
2. The backlit turn off.
1. System blank and show WM
"Check Video Cable" 20 sec then
moving about 30 sec After moving
3. If push any key in sleep mode,
then repeat item 1to 2.
WM 50 sec.
2. The backlit turn off.

8
Lock/Unlock,Aging, Service/Factory Mode
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HP L1940
Front control panel
ToLock/Unlock OSD function
AGING MODE
Nosignal input,power off -> on ,then Into thefactorymode,,afull
white pattern will bedisplayon thescreen asFig.1&Fig.2 insteadof
power savingmode.Inother words, thepower savingfunction will be
disable inthefactorymode.Supplyone signal for leavingagingmode.
SERVICE MODE
Press andholdthe"Menu" button ,power off -> on"Power",then
Into theservice mode.Press "Menu" button to bringupOSD
menufor confirmation asbelow:
Access FactoryMode
Factorymenu
Cursor can moveongraycolor area
BL : Blacklevel value
SUB-BRI : Brightness value range(MinMax)
SUB-CON : Contrastvalue range(MinMid Max)
SRGB-B : Brightness of sRGB(Reserved)
SRGB-C : Contrastof sRGB(Reserved)
AUTO-SUB: TodoAuto color function when
push "Up"keyinwhite pattern
Panel Type:Ifset this to 1,2,3,4,5 then system
will force panel type to LG(QDI), CPT orAU).
Set to other valuewill auto detect panel basedon
panel hardware.
SCALER : Read/Write scaler register
NVRAM : Read/Write eepromaddress
12345
Auto AdjustMenu-(Minus) +(Plus) Power
OSD LockTheOSD can beenabledor disabledbypressingand
holdingtheMenubutton on thefront panel for 10 seconds. If the
OSD is locked, thewarningmessage"OSD Lock" displays for
ten seconds.
If theOSD is locked, press andholdtheMenubutton for 10
seconds to unlocktheOSD.
If theOSDisunlocked, press andholdtheMenubutton for 10
seconds to locktheOSD.
1). Turn off monitor.
2). [Push "Auto Adjust"and
"+(plus)"andholdthemat thesame
time]+[Press power "Power "
button untill comesout"Windows
screen"] => then release all button,
then press "Menu" button,waituntil
theOSD menuwithCharacters"F"
(rightOSD menu) comeonthe
Screen ofthemonitor
Fig.1 Fig.2

Flat Panel Adjust 9
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HP ADJUSTMENT PATTERN.EXE
VERSION: 2.00 Rev A
OPERATING SYSTEM(S):
Microsoft Windows 98
Microsoft Windows Millennium Edition (ME)
Microsoft Windows 2000
Microsoft Windows XP 32-bit Personal
Microsoft Windows XP 32-bit Professional
DESCRIPTION: This CD contains the HP Auto-Adjustment utility, which is a
single pattern program designed to help improve the picture quality of your HP
flat panel monitor.
Note: Do not use the following procedure if your flat panel monitor is using a
DVI connector option.
To use the Adjustment pattern with your flat panel monitor:
1. Execute the auto-adjust function from the OSD main menu.
2. If the result is not satisfactory, start the "Adjustment pattern.exe" program
and repeat step 1.
Image quality characteristics that can be improved:
- Fuzzy or unclear focus
- Ghosting, streaking or shadowing effects
- Faint vertical bars
- Thin horizontal scrolling lines
- Centering the picture
Note: To achieve optimal picture performance, it is recommended that you
always set the operating system display mode to your flat panel's native
resolution. See list below for reference.
14in. and 15in. flat panels = 1024x768
17in., 18in. and 19in. flat panels = 1280x1024
20in. and 21in. flat panels = 1600x1200
HP L1940

Mechanical Instruction
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10
HP L1940
Front view
Back view
Step 1. Remove the stand.
Remove the four screws as Fig.3
Fig.3
Fig.4
Fig.2
Fig.1
Step 2. Remove the Back cover as Fig.5~8.
a.
b. Use thin "I" type screwdriver to open 4 clicks on bottom
side as Fig.5
c.
Remove the four screws on the left and right sides as Fig.4
Use thin "I" type screwdriver to open 3 clicks on right
side as Fig.6
e. Use thin "I" type screwdriver to open 3 clicks on left
side as Fig.7
f. Remove the front cover as Fig.8
g. Remove the back cover as Fig.9 ,then remove the 8 screws
Fig.5
Fig.6
Fig.7
Fig.8
Step 3. Remove the Scaler and Power board.
Remove the 9 screws and disconnect the 7 cables as Fig. 10
Fig.9
Fig. 10

Mechanical Instruction
11
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HP L1940
Step 4. Disconnect the control PCB,
as Fig.11
the scaler pcb and power pcb
Fig.11
Fig.12
Step 5 Remove the MAIN SHIELD ASSY as
FIG.12
In warranty, it is not allowed to disassembly the LCD panel, even the
backlight unit defect.
Out of warranty, the replacment of backlight unit is a correct way
when the defect is cused by backlight (CCFL,Lamp).
LPL panel

12
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LCD Monitor Quality and Pixel Policy
The TFT monitor uses high-precision technology, manufactured according to HP standards, to guarantee
trouble-free performance. Nevertheless, the display may have cosmetic imperfections that appear as small
bright or dark spots.
This is common to all LCD displays used in products supplied by all vendors and is not specific to the HP LCD.
These imperfections are caused by one or more defective pixels or sub-pixels.
1. A pixel consists of one red, one green, and one blue sub-pixel.
2. A defective whole pixel is always turned on (a bright spot on a dark background), or it is always off (a dark spot
on a bright background). The first is the more visible of the two.3. A defective sub-pixel (dot defect) is less
2. visible than a defective whole pixeland is small and only visible on a specific background.The HP display does
not have more than:
4. bright dots.
5. dark dots.
6. total bright and dark dots.
7. No more than two adjacent (less than 2.5 mm edge-to-edge) defective pixels. To locate defective pixels, the monitor
should be viewed under normal operating conditions, in normal operating mode at a supported resolution and
refresh rate, from a distance of approximately 50 cm (16 in.).HP expects that, over time, the industry will continue to
improve its ability to produce LCDs with fewer cosmetic imperfections And HP will adjust guidelines as
improvements are made.
Definition of Pixel Defects
HP L1940

13
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Electrical Instructions
PRESETVIDEORESOLUTION
HP L1940
2.3 Allowed85Hzoverscan signal modespecifiedOnce thesignal
sync input ofPCis 85Hz, this monitor is able to displayat least
for 60 seconds.An attention signal appears andshowsInput
Signal Out Of Rangefor 60 seconds,changecomputer display
input to 1280X1024 @ 60 Hz.
(MHz)
H. Freq
(KHz)
ModeResolution V. Freq
(Hz)
36.000 43.269 VESA 640 * 480 85.008
556.250 53.674 VESA 800 * 600 85.061
94.500 68.677 VESA 1024 *
768
84.997
157.5 91.146 VESA 1280 *
1024
85.024
#Resolution H-Frequency
(Hz)
Pixel
rate
(MHz)
V-Frequency
(Hz)
Comment
1 640X480 31.469K 25.175 59.940 VGA
2 640X480 37.861K 31.5 72.809 VESA
3 640X480 37.5K 31.501 75 VESA
4 720X400 31.469K 28.322 70.087 VGA
5 800X600 37.879K 40 60.317 VESA
6 800X600 48.077K 50 72.188Hz VESA
7 800X600 46.875K 49.498 75Hz VESA
8 832X624 49.726K 57.284 74.551Hz MAC
9 1024X768 48.363K 65 60.004Hz VESA
10 1024X768 56.476K 75 70.069Hz VESA
11 1024X768 60.023K 78.75 75.029Hz VESA
12 1152X870 68.68K 100 75.06Hz MAC
13 1152X900 71.71K 108 76.05Hz SUN
14 1280X1024 63.98K 108 60.02Hz VESA
15 1280X1024 79.97K 135 75.02Hz VESA
2.4 Interface
2.4.1 Analogsignal
Theinput signals are appliedto displaythrough D-sub
cable.
Length: 1.8 M +/- 50 mm (fixed)
Connector type:D-submale.
With DDC_2B pin assignments.
White connector thumb-operatedjackscrews
1. General points
1.1 Duringthetestandmeasuring, supplyadistortion free
AC mains voltagetotheapparatus via an isolated
transformer withlowinternal resistance.
1.2 All measurements mentionedhereafter are carriedout
at a normal mains voltage(90 - 132 VAC for USA
version,195-264VACfor EUROPEAN version,or 90 -
265 VAC for themodel withfull rangepower supply,
unless otherwise stated.)
1.3 All voltages are to bemeasuredor appliedwithrespect
to ground, unless otherwise stated.
Note:don‘tuseheat-sinkas ground.
1.4 Thetesthas to bedone on a complete set including
LCD panel after 30 minutes warm-upat least in a room
withtemperature of25+/-5degree C.
1.5 All values mentionedin these test instruction are only
applicable ofawell alignedapparatus withcorrect
signal.
1.6 The letters symbols (B) and(S)placedbehindthetest
instruction denotes
(B): carriedout 100% inspection at assemblyline
(S): carriedout test by sampling
1.7 Thewhite balance (color temperature)has to betested
in subduedlightedroom.
1.8 Repetitivepower on /off cycle are allowedexceptit
shouldbeavoidedwithin 6sec.
2. Input signal
2.1 Input Signal Input Definition
2.1.1 Video signal input
Signal source:pattern generator format as Table1and
Table2.
Reference generator:QuantumData 802G
Theinput signals can beappliedin twodifferent modes:
1). VESA Analog
Thevideo input consists ofred, green,andblue
signals.Thevideo signals are analoglevels,where
0V correspondstoblackand700mVis themaximum
signal amplitude.Input impedance ofvideo pins is
75 ohm +/- 1%.
2). Intel DVIDigital
Input signal:Four channel TMDS signals.Thedigital
interface shall becomprisedof2electrical layer
component:aTMDS interface for low-voltage
differential serial encodingofthedigital display
data(Panel Linkcompliant)andaDDC2B electrical
interface.Refer to theDigital DisplayWorking
Group(DDWG) document,Digital Visual
Interface(DVI)Specification,Revision 1.0 for the
exact requirements.
2.1.2 Sync signal input
Thecapabilityofsync signal inputs shall includeseparate
sync.Input impedance:2k2ohmsThesignals are
definedas follow:
Separate sync:3.3Vand5volt TTL level,
Positive/Negative
Signal source:Pattern generator format as Table1and
Table2Reference generator:QuantumData 802G
2.2 Input signal modefor Preset 15 modes
Pixel rate

2.4.2 Digital signal
The input signals are applied to display through DVI-D
cable.
Length: 1.8 M +/-50 mm (fixed)
Connector type: DVI-D male
With DDC_2B pin assignments.
White connector thumb-operated jack screws
Panel Link T.M.D.S input.
Pin assignment:
9300°K 6500°K-sRGB
x (center) 0.283 ±0.020 0.313 ±0.020
y (center) 0.297 ±0.020 0.329 ±0.020
Use Minolta CA-110 for color coordinates and luminance check.
Luminance is > 200 Nits in the center of the screen when
brightness at 100% and
contrast set to 100% at custom color (R,G,B=100%).
14 Electrical Instructions
Pin No. Description
1 T.M.D.S data2-
2 T.M.D.S data2+
3 T.M.D.S data2 shield
4 No connect
5 No connect
6 DDC clock
7 DDC data
8 No connect
9 T.M.D.S data1-
10 T.M.D.S data1+
11 T.M.D.S data 1 shield
12 No connect
13 No connect
14 +5V power
15 Ground (for +3.3V)-cable detect
16 Hot plug detect
17 T.M.D.S data0-
18 T.M.D.S data0+
19 T.M.D.S data0 shield
20 No connect
21 No connect
22 T.M.D.S clock shield
23 T.M.D.S clock+
24 T.M.D.S clock-
Set AC input at 264V / 90 V, add
2.6A loading to 12V O/P and DC O/P voltage is 12V +/- 1.2V,
1A loading to 3.3V O/P and DC O/P voltage is 3.3V +/- 0.165V,
1.5A loading to 5V O/P and DC O/P voltage is 5V +/- 0.5V.
HP L1940
4.5 EEPROM presetting (B)
After finishing all the adjustment, set:
1. Menu = Basic
2. Color = 6500K-sRGB
3. Language = English
4. Power Saver = ON
5. Power On Recall = ON
6. Mode Display = OFF
7. Horizontal OSD Position = 50%
8. Vertical OSD Position = 50%
9. OSD Timeout = 30
10. Sleep Timer = OFF
11. OSD Transparency = 0
12. Brightness = 90%
13. Contrast = 80%
4.6 When adjustment is finished, monitor should be
set to 6500K-sRGB color.
4.7 The monitor shall leave the factory with the
Power switch set to the OFF position
Go to cover page
3.POWER SUPPLY
4. DISPLAYADJUSTMENT
4.1Access to factory mode (RS232) in auto-alignment system
The communication protocol switch to RS232 .
4.2 Auto color adjustment (B)
Apply a 640*480/31.47kHz/60Hz.signal with 16-gray
level pattern, set brightness control at 90%, and contrast
control at 80%. Then, adjust the R. G. B offset, and gain
to calibrate the color smoothly and 64-gray level
distinguishable at 1280*1024/63.98kHz/60Hz.
4.3 Adjustment of WHITE-D (B)
Apply a 1280*1024 / 60Hz signal with white pattern,
set brightness control at 90%, and contrast control at 80%.
Adjust the R, G, B Sub-Gain, for the screen center, the
1931 CIEchromaticity (X, Y) co -ordinates shall be;

DDC Instructions
Pin No. Description
1 T.M.D.S. data2-
2 T.M.D.S. data2+
3 T.M.D.S. data2 shield
4 No Connect
5 No Connect
6 DDC clock
7 DDC data
8 No Connect
9 T.M.D.S. data1-
10 T.M.D.S. data1+
11 T.M.D.S. data1 shield
12 No Connect
13 No Connect
14 +5V Power
15 Ground (for +5V) - Cable detect
16 Hot plug detect
17 T.M.D.S. data0-
18 T.M.D.S. data0+
19 T.M.D.S. data0 shield
20 No Connect
21 No Connect
22 T.M.D.S clock shield
23 T.M.D.S. clock+
24 T.M.D.S. clock-
General
DDC Data Re-programming
In case the DDC data memory IC or main EEPROM which storage all
factory settings were replaced due to a defect, the serial numbers have
to be re-programmed "Analog DDC IC, Digital DDC IC & EEPROM".
It is advised to re-soldered DDC IC and main EEPROM from the old
board onto the new board if circuit board have been replaced, in this case
the DDC data does not need to be re-programmed.
Additional information
Additional information about DDC (Display Data Channel) may be
obtained from Video Electronics Standards Association (VESA).
Extended Display Identification Data(EDID) information may be also
obtained from VESA.
1. An i486 (or above) personal computer or compatible.
2. Microsoft operation system Windows 95/98 .
Y o Install the EDID_PORT_Tool under Win2000/XP . As
Fig. 1 .
A. Cody the "UserPort.sys" to C:\WINNT\system32\drivers(win2000)
C:\WINDOWS\system32\drivers(winXP)
B. Running " io.exe" everytime, Before you start to programming
edid data .
4. A/D Alignment kits (12NC: 3138 106 10079):
inclusion : a. Alignment box x1 (Fig. 2)
b. Printer cable x1
c. (D-Sub) to (D-Sub) cable x1
D. (D-Sub) to (DVI) cable x1
System and equipment requirements
ou have t
3. EDID46.EXE program
Fig. 1
Fig. 1
Fig. 2
To Monitor
D-sub/DVI cable
DC 8~12V
To Printer port
Power
indicator
Note: The alignment box has already build-in a batteries socket for
using batteries (8~12V) as power source. Pull out the socket by
remove four screws at the rear of box. Please do not forget that
remove batteries after programming. The energy of batteries can
only drive circuits for a short period of time.
PIN No. SIGNAL
1 Red video input
2 Green video input / sync on green
3 Blue video input
4GND
5 GND - Cable detect
6RedvideoGND
7 Green video GND
8 Blue video GND
9DDC+3.3Vor+5V
10 Logic GND
11 GND
12 Serial data line (SDA)
13 H-sync / H+V
14 V-sync
15 Data clock line (SCL)
Pin assignment
A. 15-pin D-Sub Connector
B. Input DVI -D Connector pin
Fig. 3
Go to cover page
15
HP L1940

DDC Instructions
Step 3: Installation of EDID46.EXE
Method 1: Start on DDC program
Start Microsoft Windows.
1. The Program"EDID46.EXE" in service manual cd-rom be copyed to C:\ .
2. Click , choose Run at start menu of Windows as shown
In Fig. 5.
Fig. 5
4. Click OK button. The main menu appears (as shown in Fig. 7).
This is for initialize alignment box.
Fig. 7
Fig. 6
3. At the submenu, type the letter of your computer's hard disk drive
followed by :EDID46 (for example, C:\EDID46, as shown in Fig. 6).
Note 2: During the loading, EDID46 will verify the EDID data which just
loaded from monitor before proceed any further function, once
the data structure of EDID can not be recognized, the following
error message will appear on the screen as below. Please
confirm following steps to avoid this message.
1. The data structure of EDID was incorrect.
2. DDC IC that you are trying to load data is empty.
3. Wrong communication channel has set at configuration setup
windows.
4. Cables loosed or poor contact of connection.
1
Fig. 8
Note 1: If the connection is improper, you will see the following error
message (as shown in Fig. 8) before entering the main menu.
Meanwhile, the (read EDID) function will be disable. At this
time, please make sure all cables are connected correctly and
fixedly, and the procedure has been performed properly.
Fig. 9
Configuration and procedure
There is no Hardware DDC (DDC IC) anymore. Main EEPROM stores
all factory settings and DDC data (EDID code) which is also called
Software DDC. The following section describes the connection and
procedure for Software DDC application. The main EEPROM can be re-
programmed by enabling '' factory memory data write'' function on the
DDC program (EDID46.EXE).
Initialize alignment box
In order to avoid that monitor entering power saving mode due
to sync will cut off by alignment box, it is necessary to initialize
alignment box before running programming software
(EDID46.EXE). Following steps show you the procedures and
connection.
Step 1: Supply 8-12V DC power source to the Alignment box by
plugging a DC power cord .
Step 2: Connecting printer cable and D-Sub cable of monitor as Fig. 4
Fig. 4
PC 1=Power connector
2=D-SUB connector
To printer port (LTP1)
DC Power
8-12 V
Printer
Port
To
Monitor
To PC
12
----->
----->
16
Go to cover page
HP L1940

DDC Instructions
Step 3: Modify DDC data (verify EDID version, week,
year)
Click (new function) icon from the tool bar, bring up
Step 1 of 9 as shown in Fig. 14 .
EDID46 DDC application provides the function selection and
Step 4: Modify DDC data (Monitor Serial No.)
1. Click Next , bring up Fig. 15.
3. Click OK button to confirm your selection.
4. Click icon (Read EDID function) to read DDC EDID data from
monitor. The EDID codes will display on screen as shown in Fig. 13.
Fig. 15
2. Select the DDC2Bi as the communication channel.
As shown in Fig. 12.
Fig. 12
Fig. 13
Fig. 14
Select and fill out,
If necessary.
Re-programming Analog DDC IC
Step 1: After initialize alignment box, connecting all
cables and box as shown in Fig. 10.
Fig. 11
Step 2: Read DDC data from monitor
1. Click icon as shown in Fig. 11 from the tool bar to bring up
the Channels "Configuration Setup" windows as shown in Fig. 11.
Fig. 10
1=Power connector
2=D-SUB connector
PC
To printer port (LTP1)
DC Power
8-12V
Printer
Port
To
Monitor
To PC
12
----->
----->
To PCVideo port (D-sub)
Click this button
=====>
Go to cover page
17
HPL1940

DDC Instructions
Fig. 21
Fig. 18
Fig. 19
7. Click Next , bring up Fig. 21.
4. Click Next , bring up Fig.18.
5. Click Next , bring up Fig.19.
6. Click Next , bring up Fig. 20.
In this step, please confirm the Descriptor Data Type is
Monitor Range Limits, and all the items are same as below.
Fig. 20
2. Click Next , bring up Fig.16.
Fig. 16
Fig. 17
3. Click Next , bring up Fig.17.
Go to cover page
18 HP L1940

DDC Instructions
Go to cover page
19
4). Click (Write EDID) icon from the tool bar to write DDC data. then
the screen will be black for 5-10 seconds, when the screen
recovers ,DDC data will be finished Writing.
2. Access Factory Mode
2). [Push "Auto Adjust " and" +(plus)"and hold them at the same
time ] + [Press power "Power " button untill comes out "Windows
screen"] => then release all button, then press "Menu" button, wait
until the OSD menu with Characters "F" (below OSD menu) come
on the Screen of the monitor (see Fig. 24).
1). Turn off monitor.
Fig. 24
3) Push Menu to exit OSD menu.""
Fig. 22
8. Click Next , bring up Fig. 22.
- Click Finish to exit the Step window.
- Serial number can be filled up at this moment (for example,
TWP318Q001).
NOTE: You must modify the Serial NO. In step 9, otherwise the Serial NO.
In OSD Couldn't be modified correctly.
Step 5: Write DDC data
1. Configuration should be as Fig. 23. And press OK.
Fig. 23
2. Click Save.
Step 7: Exit DDC program
Pull down the File menu and select Exit as shown in Fig. 26.
Step 6: Save DDC data
Sometimes, you may need to save DDC data as a text file
for using in other IC chip. To save DDC data, follow the
steps below:
1. Click (Save) icon (or click "file"-> "save as") from the tool
bar and give a file name as shown in Fig. 25.
The file type is EDID46 file (*.ddc) which can be open in
WordPad. By using WordPad, the texts of DDC data & table
(128 bytes, hexcode) can be modified. If DDC TEXTS &
HEX Table ar completely correct, it can be saved as .ddc flie
to re-load it into DDC IC for DDC Data application.
Fig. 26
Step 8: Turn off the monitor, exit the factory mode.
Fig. 25
Factory Mode
Indicator
----------------->
HP L1940

20
Go to cover page
DDC Instructions
HP L1940
Step 3: Modify DDC data (verify EDID version, week,
year)
Click (new function) icon from the tool bar, bring up
Step 1 of 9 as shown in Fig. 31 .
EDID46 DDC application provides the function selection and
text change (select & fill out) from Step 1 to Step 9.
Step 4: Modify DDC data (Monitor Serial No.)
1. Click Next , bring up Fig. 32.
3. Click OK button to confirm your selection.
4. Click icon (Read EDID function) to read DDC EDID data from
monitor. The EDID codes will display on screen as shown in Fig. 30.
Fig. 32
2. Select the DDC2Bi as the communication channel.
As shown in Fig. 29.
Fig. 29
Fig. 30
Fig. 31
Select and fill out,
If necessary.
Re-programming Digital DDC IC
Step 1: After initialize alignment box, connecting all
cables and box as shown in Fig. 27.
Fig. 28
Step 2: Read DDC data from monitor
1. Click icon as shown in Fig. 11 from the tool bar to bring up
the Channels "Configuration Setup" windows as shown in Fig. 28.
Fig. 27
Click this button
=====>
D-sub to DVI-D cable
1=DVI-D connector
2=D-sub connector
3=Power Plug
2
1
3
D-sub cable
DC Power
8 12V~
PC
To video card
To printer port (LTP1)
To
Monitor
Printer
Port
Fig. 38
Fig. 35 Fig. 36
7. Click Next , bring up Fig. 38.
4. Click Next , bring up Fig. 35.
5. Click Next , bring up Fig. 36.
6. Click Next , bring up Fig. 37.
In this step, please confirm the Descriptor Data Type is
Monitor Range Limits, and all the items are same as below.
Fig. 37
2. Click Next , bring up Fig. 33.
Fig. 33 Fig. 34
3. Click Next , bring up Fig. 34.