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COLOR MONITOR
SERVICE MANUAL
CHASSIS NO. : CL-42
MODEL: L1910P (L1910PL-AF**R)
( ) **Same model for Service


CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.




*To apply the Mstar Chip.
CONTENTS
SPECIFICATIONS ................................................... 2 ADJUSTMENT ...................................................... 13
PRECAUTIONS ....................................................... 4 TROUBLESHOOTING GUIDE .............................. 14
TIMING CHART ....................................................... 5 PRINTED CIRCUIT BOARD................................... 18
OPERATING INSTRUCTIONS ................................ 6 EXPLODED VIEW...................................................21
WIRING DIAGRAM ................................................. 9 REPLACEMENT PARTS LIST ...............................23
BLOCK DIAGRAM ..................................................10 PIN CONFIGURATION............................................27
DESCRIPTION OF BLOCK DIAGRAM...................11 SCHEMATIC DIAGRAM ......................................... 28

SPECIFICATIONS
1. LCD CHARACTERISTICS
Type : TFT Color LCD Module 5. POWER SUPPLY
Size : 19inch(48cm )diagonal
Pixel Pitch : 0.294(H) x 0.294(V) 5-1. Power Adaptor(Built-in Power)
Color Depth : 8-bit, 16,777,216 colors Input : AC 100-240V~, 50/60Hz , 1.0A
Electrical Interface : LVDS 5-2. Power Consumption
Surface Treatment : Anti-Glare, Hard Coating(3H) MODE H/V SYNC VIDEO POWER CONSUMPTION LED COLOR
Operating Mode : Normally Black
POWER ON (NORMAL) ON/ON ACTIVE less than 43 W GREEN
Backlight Unit : 4-CCFL (Cold Cathode
Fluorescent Lamp) STAND-BY OFF/ON OFF less than 3 W AMBER

SUSPEND ON/OFF OFF less than 3 W AMBER
2. OPTICAL CHARACTERISTICS
2-1. Viewing Angle by Contrast Ratio 10 DPM OFF OFF/OFF OFF less than 3 W AMBER

Left : -80° min., -85°(Typ)
Right : +80° min., +85°(Typ) 6. ENVIRONMENT
Top : +80° min., +85°(Typ) 6-1. Operating Temperature: 10°C~35°C (50°F~95°F)
Bottom : -80° min., -85°(Typ) (Ambient)
6-2. Relative Humidity : 10%~80%
2-2. Luminance : 240(min), 300(Typ) (Non-condensing)
2-3. Contrast Ratio : 400(min), 700(Typ) 6-3. MTBF : 50,000 Hours
Lamp Life : 30,000 Hours(Typ)
3. SIGNAL (Refer to the Timing Chart)
3-1. Sync Signal 7. DIMENSIONS (with TILT/SWIVEL)
· Type : Separate, Composite,
SOG (Sync On Green) Width : 413 mm (16.25'')
Digital Depth : 223 mm (8.78'')
Height : 435mm (17.13'')
3-2. Video Input Signal
1) Type : R, G, B Analog
8. WEIGHT (with TILT/SWIVEL)
2) Voltage Level : 0~0.7 V
a) Color 0, 0 : 0 Vp-p Net. Weight : 7.20kg (15.87 lbs)
b) Color 7, 0 : 0.35 Vp-p Gross Weight : 9.83kg (21.67 lbs)
c) Color 15, 0 : 0.7 Vp-p
3) Input Impedance : 75 9. USB
Upstream : 1 port, Downstream : 2 port
3-3. Operating Frequency Speed : Full-12Mbps, Low-1.5Mbps
Horizontal(Analog) : 30 ~ 83kHz
Horizontal(Digital) : 30 ~ 71kHz
Vertical : 56 ~ 75Hz

4. MAX. RESOLUTION
D-sub Analog : 1280 x 1024@75Hz
DVI Digital/Analog : 1280 x 1024@60Hz


-2-
Signal Connector Pin Assignment


· DVI-I Connector (Digital/Analog)
Pin Signal (DVI-I) Pin Signal (DVI-I)
1 T. M. D. S. Data2- 16 Hot Plug Detect
8 C1 C2 2 T. M. D. S. Data2+ 17 T. M. D. S. Data0-
1
9 16 C5 3 T. M. D. S. Data2/4 Shield 18 T. M. D. S. Data0+
17 24 C3 C4 4 T. M. D. S. Data4- 19 T. M. D. S. Data0/5 Shield
5 T. M. D. S. Data4+ 20 T. M. D. S. Data5-
6 DDC Clock 21 T. M. D. S. Data5+
7 DDC Data 22 T. M. D. S. Clock Shield
8 Analog Vertical Sync. 23 T. M. D. S. Clock+
9 T. M. D. S. Data1- 24 T. M. D. S. Clock-
10 T. M. D. S. Data1+ C1 Analog Red
11 T. M. D. S. Data1/3 Shield C2 Analog Green
12 T. M. D. S. Data3- C3 Analog Blue
13 T. M. D. S. Data3+ C4 Analog H. Sync.
14 +5V Power C5 Analog Ground
15 Ground (return for +5V,
H. Sync. and V. Sync.)

T. M. D. S. (Transition Minimized Differential Signaling)




-3-
PRECAUTION
WARNING FOR THE SAFETY-RELATED COMPONENT. WARNING
· There are some special components used in LCD BE CAREFUL ELECTRIC SHOCK !
monitor that are important for safety. These parts are
· If you want to replace with the new backlight (CCFL) or
marked on the schematic diagram and the
inverter circuit, must disconnect the AC adapter
replacement parts list. It is essential that these critical
because high voltage appears at inverter circuit about
parts should be replaced with the manufacturer's
650Vrms.
specified parts to prevent electric shock, fire or other
hazard.
· Handle with care wires or connectors of the inverter
· Do not modify original design without obtaining written circuit. If the wires are pressed cause short and may
permission from manufacturer or you will void the burn or take fire.
original parts and labor guarantee.


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 are
grounded through wrist band.
· Do not leave the module in high temperature and in
areas of high humidity for a long time.
· The module not be exposed to the direct sunlight.
· Avoid contact with water as it may a short circuit within
the module.
· If the surface of panel become dirty, please wipe it off
with a softmaterial. (Cleaning with a dirty or rough cloth
may damage the panel.)

CAUTION
Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.




-4-
TIMING CHART

VIDEO
B A


E
C
F
D
SYNC



<< Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >>
H/V Sync Dot Total Period Video Active Time Front Porch Sync Duration Back Porch
Mode Clock Frequency Resolution
Sort Polarity (E) (A) (C) (D) (F)
H + 31.469 800 640 16 96 48 640x350
1 25.175
V ­ 70.8 449 350 37 2 60 70Hz
H ­ 31.468 900 720 18 108 54 720x400
2 28.321
V + 70.09 449 400 12 2 35 70Hz
H ­ 31.469 800 640 16 96 48 640x480
3 25.175
V ­ 59.94 525 480 10 2 33 60Hz
H ­ 37.5 840 640 16 64 120 640x480
4 31.5
V ­ 75 500 480 1 3 16 75Hz
H + 37.879 1056 800 40 128 88 800x600
5 40.0 60Hz
V + 60.317 628 600 1 4 23
H + 46.875 1056 800 16 80 160 800x600
6 49.5
V + 75.0 625 600 1 3 21 75Hz
H +/­ 49.725 1152 832 32 64 224 832x624
7 57.283
V +/­ 74.55 667 624 1 3 39 75Hz
H ­ 48.363 1344 1024 24 136 160 1024x768
8 65.0 60Hz
V ­ 60.0 806 768 3 6 29
H ­ 60.123 1312 1024 16 96 176 1024x768
9 78.75 75Hz
V ­ 75.029 800 768 1 3 28
H +/­ 68.681 1456 1152 32 128 144 1152x900
10 100.0 75Hz
V +/­ 75.062 915 870 3 3 39
H +/­ 61.805 1504 1152 18 134 200 1152x900
11 92.978 65Hz
V +/­ 65.96 937 900 2 4 31
H + 63.981 1688 1280 48 112 248 1280x1024
12 108.0 60Hz
V + 60.02 1066 1024 1 3 38
H + 79.976 1688 1280 16 144 248 1280x1024
13 135.0 75Hz
V + 75.035 1066 1024 1 3 38




-5-
OPERATING INSTRUCTIONS

FRONT VIEW REAR VIEW




D-Sub Signal
Connect




DVI Connect
Stand
Lock


Power Connect
Front Control Panel
USB Port

Front Control Panel



LightView




6 4 3 5 1 2

1. Power ON/OFF Button 4. MENU Button
Use this button to turn the monitor on or off. Use this button to enter or exit the On Screen Display.

2. Power Indicator 5.AUTO/SELECT Button
This indicator lights up green when the monitor Use this button to enter a selection in the On Screen Display.
operates normally. If the display is in DPM(Energy
Saving)mode, this indicator color change to amber. When adjusting your display settings,
always press the AUTO/SELECT button
3. Button
before entering the On Screen
Use these buttons to choose or adjust items in the On Screen
Display(OSD). This will automatically adjust your display
Display.
image to the ideal settings for the current screen resolution
This function optimizes the brightness, contrast or
color value to the surrounding conditions and settings size(display mode). The best display mode is
and enables you to enjoy the most suitable picture by
adjusting the surroundings (DAY/NIGHT/USER 1280x1024/60Hz.
MODE).
· TEXT: For viewing letters 6. SOURCE Button
· MOVIE: For viewing movies
· PHOTO: For viewing pictures or the photographs Use this button to make Dsub or DVI connector active.
· USER MODE: This function memorizes the
manual adjustment -Brightness, Contrast and This feature is used when two computers are connected to the
Color value on the On Screen Display. monitor. The default setting is Dsub.
100


100
Bring up Contrast and Brightness adjustment.
:



-6-
CONTROLS LOCKED/UNLOCKED
: MENU and
This function allows you to secure the current control settings, so that they cannot be inadvertently
changed. Press and hold the MENU button and button for 3 seconds: the message "CONTROLS
LOCKED" appears.
You can unlock the OSD controls at any time by pushing the MENU button and button for 3 seconds:
the message "CONTROLS UNLOCKED" will appear.




Before setting up the monitor, ensure that the power to the monitor, the computer system, and other
attached devices is turned off.
Positioning your display
1. Adjust the position of the panel in various ways for maximum comfort.
Tilt Range : -5°~30°




Height Range : maximun 3.15 inch (80.0mm)
80.0mm




Unfasten the [Stand lock]
clockwise to adjust the
height of the stand.




Landscape & Portrait : You can rotate the panel 90o clockwise.
(* For detailed information, please refer to the Pivot Sofeware CD provided.)




* Make sure not to touch the
floor when the head rotates
to use the Pivot function.


Ergonomic
It is recommended that in order to maintain an ergonomic and comfortable viewing position, the forward tilt angle of the monitor should not
exceed 5 degrees.


-7-
Making use of USB (Universal Serial Bus)*
USB (Universal Serial Bus) is an innovation in connecting your different desktop peripherals conveniently to your
computer. By using the USB, you will be able to connect your mouse, keyboard, and other to your monitor instead of
having to connect them to your computer. This will give you greater flexibility in setting up your system. USB allows you
to connect chain up to 120 devices on a single USB port, and you can "hot" plug (attach them while the computer is
running) or unplug them while maintaining Plug and Play auto detection and configuration. This monitor has an integrated
BUS-powered USB hub, allowing up to 2 other USB devices to be attached it.


USB connection
1. Connect the upstream port of the Display to the downstream port of the USB compliant PC or another hub using the
USB cable. (Computer must have a USB port)
2. Connect the USB compliant peripherals to the downstream ports of the monitor.




This is a simplified representation
of rear view.

USB upstream Port




To USB downstream port of
the USB compliant PC or
another hub cable

PUSH




USB downstream Port
connect the cables from USB compliant
peripherals-such as keyboard, mouse,
etc




NOTE
To activate the USB hub function, the monitor must be connected to a USB compliant PC(OS) or another hub with the USB
cable(enclosed).
When connecting the USB cable, check that the shape of the connector at the cable side matches the shape at the connecting
side.
Even if the monitor is in a power saving mode, USB compliant devices will function when they are connected the USB ports(both
the upstream and downstream) of the monitor.




-8-
WIRING DIAGRAM




Connector Ass'y P/N: 6631T20023E




Connector Ass'y P/N:
CN105 CN104
6631T11012W

CN002


J705 J702

J706



CN102 CN103




Connector Ass'y P/N:
6631T20022E




-9-
5V
12V Inverter LCD Module Bus-power USB D/S
Inverter Output

USB D/S
LVDS
R,G,B (Low Voltage
HUB
5V 5V
differential Differential U/S
Signaling)

3.3V 2.5V
Reg. Reg.


3.3V 2.5V MST9151
2.5V
including
(ADC/LVDS/SCALER MTV312




- 10 -
3.3V
/INPUT SWITCHING Micom
12V 5V /TMDS )
BLOCK DIAGRAM




Power


AC Input


Digital Signal or
D-SUB R,G,B, H/V Sync DVI-I
Analog R,G,B,H/V
DESCRIPTION OF BLOCK DIAGRAM

1. Video Controller Part & Display Data Transmitter Part.(MST9151)
This part amplifies the level of video signal for the digital conversion and
converts from the analog video signal to the digital video signal using a pixel clock.
The pixel clock for each mode is generated by the PLL.
The range of the pixel clock is from 25MHz to 135MHz.
This part consists of the Scaler.
The Scaler gets the video signal converted analog to digital,
interpolates input to 1280 x 1024 resolution signal and outputs 8-bit R, G, B signal to transmitter.
Especially pre-amp / ADC / Video controller/ Transmitter are merged to one chip"MST9151" by MSTAR.
This part transmit digital signal from the Scaler to the receiver of module.

2. Micom Part
This Part consists of EEPROM IC which stores control data, Reset IC and the Micom.
The Micom distinguishes polarity and frequency of the H/V Sync are supplied from signal cable.
The controlled data of each modes is stored in EEPROM.

3. Power Part
This part consists of the one 3.3V and one 2.5 regulators to convert power which is provided 5V in LIPS Board.
5V is provided for LCD Panel.
Also, 5V is converted 3.3V and 2.5V by regulator. Converted power is provided for IC in the main board.

4. Inverter
The inverter converts from DC12V to AC 700Vrms and operates back-light lamps of module.




- 11 -
LIPS Board Block Diagram



12V
50 ~ 60Hz


HVDC 100KHz 5V
EMI INPUT RECTIFIER ENERGY OUTPUT RECTIFIER
COMPONENTS AND FILTER TRANSFER AND FILTER
LINE GND
100 ~ 240V




SIGNAL
PWM CONTROL PHOTO-COUPLER COLLECT-
CIRCUIT ISOLATION ON



PRIMARY SECONDARY


12V High Voltage output
INVERTER CIRCUIT




Operation description_LIPS
1. EMI components.
This part contains of EMI components to comply with global marketing EMI standards like FCC, VCCI CISPR, the
circuit included a line-filter, across line capacitor and of course the primary protection fuse.

2. Input rectifier and filter.
This part function is for transfer the input AC voltage to a DC voltage through a bridge rectifier and a bulk capacitor.

3. Energy Transfer.
This part function is transfer the primary energy to secondary through a power transformer.

4. Output rectifier and filter.
This part function is to make a pulse width modulation control and to provide the driver signal to power switch, to
adjust the duty cycle during different AC input and output loading condition to achive the dc output stablize, and also
the over power protection is also monitor by this part.

5. Photo-Coupler isolation.
This part function is to feed back the dc output changing status through a photo transistor to primary controller to
achieve the stabilized dc output voltage.

6. Signal collection.
This part function is to collect the any change from the dc output and feed back to the primary through photo
transistor.

7. Inverter
The inverter converts from DC12V to AC 700V and operate back-light lamp of module.




- 12 -
ADJUSTMENT
All adjustment are thoroughly checked and corrected when the monitor leaves the factory, but sometimes several minor
adjustment may be required.
Adjustment should be following procedure and after warming up for a minimum of 10 minutes.
· Alignment appliances and tools.
- IBM compatible PC
- Programmable Signal Generator.
(eg. VG-819 made by Astrodesign Co.)
- E(E)PROM with each mode data saved.

1. Adjustment process for LCD MONITOR
1) Display half window pattern(or mixed white and black pattern)at Mode 8 (1024x768@60Hz).
2) Press the POWER and MENU key at the same time to light monitor, then go to adjustment mode.
3) Press the MENU s/w, next press UP button, you will see adjustment OSD menu.
4) Press the AUTO/SELECT to select the adjustment item first(use the same button to exit)next do the operation to
the relative item.Ex) 17HYDIS is used at 17AU, press right button to select. Press the AUTO/SELECT then
selected proper Module.
5) Press down button to move the place of ADC CAL. Press the AUTO/SELECT to select, right button is pressed for
adjustment.
6) When adjustment is finished, press the POWER key twice to light monitor again. The adjustment ends.

2. Adjustment for EDID
1) Use this procedure only when there is some probelm on EDID data.
2) Connect the D-sub cable.
3) Select EDID Write EDID[A0] command and Enter.




A

9 6
IBM 5 1
15 11
Video Signal Compatible PC 10 6
Generator 5 1
C

PARALLEL PORT 13 1
d
se




25 14
tu


C
No




OFF ON
32




5V
2
RS




F
EL
Control Line




LL




C
RA
PA




5V
Power inlet (required) 4.7K
220
ON 5V 4.7K
Power Select Switch
E
R




VG
WE




S 74LS06
(110V/220V)
PO




OFF 4.7K
A
ST




MO Power LED
C




NI
YN




TO
74LS06
V-S




R



E ST Switch
B B

F V-Sync On/Off Switch
(Switch must be ON.)


Figure 1. Cable Connection


- 13 -
TROUBLESHOOTING GUIDE
1. NO POWER


NO POWER
(POWER INDICATOR OFF)



CHECK POWER
CHECK J709 BOARD, AND FIND
NO
VOLTAGE OUT A SHORT POINT
PIN5, PIN6 (5V)? AS OPENING
EACH POWER LINE
YES


CHECK
U803 PIN 3 NO
CHECK U803.
VOLTAGE
(5V) ?
YES


CHECK
NO CHECK 5VS LINE
U804 PIN 3 Voltage
(OPEN CHECK)
(5V) ?
NO PROBLEM
YES



CHECK KEY CONTROL
CONNECTOR ROUTINE




IS U201
PIN114 (3.3V) NO
VOLTAGE REPEATED
AS PULSE
SHAPE ?

YES



CHECK IIC LINE
CHECK U201 VCC,
CONNECTION
XTAL, RESET
(U501, U502)




- 14 -
2. NO RASTER (OSD IS NOT DISPLAYED) ­ LIPS



NO RASTER
(OSD IS NOT DISPLAYED)




J705
NO
PIN5, PIN 6 CHECK LIPS
5V?

YES



J705 PIN9 NO CHECK MICOM INV
5V? ON/OFF PORT.


YES

1. CONFIRM BRIGHTNESS
J705 PIN7 NO OSD CONTRL STATE.
5V? 2. CHECK MICOM DIM-ADJ
PORT

YES




CHECK
PULSE AS
CONTACTING SCOPE
PROBE TO CAUTION LABEL. NO
(CONTACT PROBE TO LIPS
CAUTION LABEL.
CAN YOU SEE PULSE
AT YOUR
SCOPE?


YES




REPLACE CCFL LAMP
IN THE LCD MODULE




- 15 -
3. NO RASTER (OSD IS NOT DISPLAYED) ­ MST9151


NO RASTER
(OSD IS NOT DISPLAYED)




U201 NO
POWER PINS CHECK U804, U803
3.3V/2.5V?


YES


U201 1. CHECK PIN122, 123
PIN122, 123 NO SOLDERING CONDITION
OSCILLATE AS 2. CHECK X501
12MHZ? 3. TROUBLE IN U201



YES




U501
PIN41 IS 64KHz H-SYNC? NO
CHECK CONNECTION LINE
PIN42 IS 60Hz V-SYNC?
FROM U201 TO U501
IS PULSE APPEARED
AT SIGNAL PINS?




YES


TROUBLE IN CABLE
OR LCD MODULE




- 16 -
4. TROUBLE IN DPM


TROUBLE IN DPM




CHECK NO CHECK PC
R734, R741 PC IS NOT GOING
(SYNC) ? INTO DPM OFF MODE


YES



CHECK
U501 PIN 11, 12 NO TROUBLE IN
WAVEFORM X501
(12MHz) ?


YES



CHECK NO TROUBLE IN
U501 PIN 24
SIGNAL CABLE
(0V) ?


YES




TROUBLE IN PC




- 17 -
- 18 -
J708




Q507 Q508 C708 C709 C711
C




R529 R528 R708
C509




C508
R554




R553
R555
R556




R581 R580 R747 R709
C516 R571 R570 R748 C710
R537 R562 R560 Q704
1
R533
J706
R711 R534 R552 R766
R710
C




R559 R539
R513
U502
R765




R763




R557
U703




R764




1




C550
R531
R530




R762
J702




R550
C514
R532
D719




Q703 C712
5
40




Q502
R744
U503 R724
R745
C507
R739
U702




R718
C530 Q509
Q503




ZD710
R558
R535
R723




R726
R542




R561
C501




R727
C513