LG M1721A User manual

COLOR MONITOR
SERVICE MANUAL
Website:http://biz.LGservice.com
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS NO. : LP68A
MODEL: M1721A (M1721A-BZH.A**OPP)
M1921A (M1921A-BZH.A**OPP)
*( ) **Same model for Service

- 2 -
CONTENTS
SPECIFICATIONS
SPECIFICATIONS ................................................... 2
PRECAUTIONS ....................................................... 3
SERVICE PRECAUTIONS ...................................... 4
TIMING CHART ....................................................... 7
DISASSEMBLY ....................................................... 8
BLOCK DIAGRAM ................................................... 9
DESCRIPTION OF BLOCK DIAGRAM ................. 11
ADJUSTMENT ...................................................... 12
TROUBLESHOOTING GUIDE .............................. 14
WIRING DIAGRAM ............................................... 18
EXPLODED VIEW...................................................19
REPLACEMENT PARTS LIST ...............................21
SCHEMATIC DIAGRAM......................................... 27
1. LCD CHARACTERISTICS
Type : TFT Color LCD Module
Active Video Area : 17.0 inch-M1721A
: 19.0 inch-M1921A
Size : 358.5(V) x 296.5(H) x 15(D)-M1721A
: 396.0(V) x 324.0(H) x 15(D)-M1921A
Pixel Pitch : 0.264mm x 0.264mm-M1721A
: 0.294mm x 0.294mm-M1921A
Color Depth : 6Bits with A-FRC, 16,777,216 colors
Surface Treatment : Anti Glare, Hard Coating(3H)
Operating Mode : Normally white
Backlight Unit : 4CCFL (4Lamps)
Electrical Interface : LVDS
2. OPTICAL CHARACTERISTICS
2-1. Viewing Angle by Contrast Ratio ≥10
Left : +70° min., +80° typ / Right : +70° min., +80° typ
Top : +60° min., +75° typ / Bottom : +70° min., +85° typ
2-2. Luminance : 180(min.), 250(typ.)
2-3 Contrast Ratio : 3000(min.)
3. SIGNAL (Refer to the Timing Chart)
3-1. Analog Video Input
1) Video Input Range : 0~0.7V ± 5%
2) Video Termination Impedance : 75Ω±5%
3) Sync Type : Separate Sync.
4) Sync Level : TTL Low ≤0.8V, High ≥2.0V
3-2. Operating Frequency
Horizontal : 30 ~ 70kHz
Vertical : 56 ~ 75Hz
4. RESOLUTION
Analog Max : 1280 x 1024@60Hz
5. POWER SUPPLY
5-1. Power
AC 100-240Vac, 50/60Hz
5-2. Power Consumption
6. ENVIRONMENT
5-1. Operating Temperature : 10°C ~ 35°C
5-2. Operating Humidity : 20% ~ 80%
5-3. MTBF : 50,000 Hours (Min)
7. DIMENSIONS (with TILT/SWIVEL)
M1721A
Width : 394.4 mm (15.53'')
Depth : 243 mm (9.57'')
Height : 404 mm (15.91'')
M1921A
Width : 445 mm (17.52'')
Depth : 243 mm (9.57'')
Height : 457 mm (17.99'')
8. WEIGHT (with TILT/SWIVEL)
M1721A
Net. Weight : 4.5 kg (9.92 lbs)
Gross Weight : 6.2 kg (14.33 lbs)
M1921A
Net. Weight : 5.5 kg (12.13 lbs)
Gross Weight : 7.1 kg (15.66 lbs)
H/V SYNC
ON/ON
OFF/ON
-
MODE
POWER ON (NORMAL)
SLEEP MODE
POWER S/W OFF
VIDEO
ACTIVE
OFF
OFF
POWER CONSUMPTION
less than 45 W
less than 1 W
less than 1 W
LED COLOR
GREEN
RED
OFF

PRECAUTION
- 3 -
WARNING FOR THE SAFETY-RELATED COMPONENT.
• There are some special components used in LCD
monitor that are important for safety. These parts are
marked on the schematic diagram and the
replacement parts list. It is essential that these critical
parts should be replaced with the manufacturer’s
specified parts to prevent electric shock, fire or other
hazard.
• Do not modify original design without obtaining written
permission from manufacturer or you will void the
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.)
WARNING
BE CAREFUL ELECTRIC SHOCK !
• If you want to replace with the new backlight (CCFL) or
inverter circuit, must disconnect the AC adapter
because high voltage appears at inverter circuit about
650Vrms.
• Handle with care wires or connectors of the inverter
circuit. If the wires are pressed cause short and may
burn or take fire.
Leakage Current Hot Check Circuit
CAUTION
Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.
1.5 Kohm/10W
To Instrument's
exposed
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter

SERVICING PRECAUTIONS
- 4 -
CAUTION: Before servicing receivers covered by this
service manual and its supplements and addenda, read
and follow the SAFETY PRECAUTIONS on page 3 of this
publication.
NOTE: If unforeseen circumstances create conflict
between the following servicing precautions and any of the
safety precautions on page 3 of this publication, always
follow the safety precautions. Remember: Safety First.
General Servicing Precautions
1. Always unplug the receiver AC power cord from the AC
power source before;
a. Removing or reinstalling any component, circuit
board module or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical
plug or other electrical connection.
c. Connecting a test substitute in parallel with an
electrolytic capacitor in the receiver.
CAUTION: A wrong part substitution or incorrect
polarity installation of electrolytic capacitors may
result in an explosion hazard.
d. Discharging the picture tube anode.
2. Test high voltage only by measuring it with an
appropriate high voltage meter or other voltage
measuring device (DVM, FETVOM, etc) equipped with
a suitable high voltage probe.
Do not test high voltage by "drawing an arc".
3. Discharge the picture tube anode only by (a) first
connecting one end of an insulated clip lead to the
degaussing or kine aquadag grounding system shield
at the point where the picture tube socket ground lead
is connected, and then (b) touch the other end of the
insulated clip lead to the picture tube anode button,
using an insulating handle to avoid personal contact
with high voltage.
4. Do not spray chemicals on or near this receiver or any
of its assemblies.
5. Unless specified otherwise in this service manual,
clean electrical contacts only by applying the following
mixture to the contacts with a pipe cleaner, cotton-
tipped stick or comparable non-abrasive applicator;
10% (by volume) Acetone and 90% (by volume)
isopropyl alcohol (90%-99% strength)
CAUTION: This is a flammable mixture.
Unless specified otherwise in this service manual,
lubrication of contacts in not required.
6. Do not defeat any plug/socket B+ voltage interlocks
with which receivers covered by this service manual
might be equipped.
7. Do not apply AC power to this instrument and/or any of
its electrical assemblies unless all solid-state device
heat sinks are correctly installed.
8. Always connect the test receiver ground lead to the
receiver chassis ground before connecting the test
receiver positive lead.
Always remove the test receiver ground lead last.
9. Use with this receiver only the test fixtures specified in
this service manual.
CAUTION: Do not connect the test fixture ground strap
to any heat sink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid-state) devices can be
damaged easily by static electricity. Such components
commonly are called Electrostatically Sensitive (ES)
Devices. Examples of typical ES devices are integrated
circuits and some field-effect transistors and
semiconductor "chip" components. The following
techniques should be used to help reduce the incidence of
component damage caused by static by static electricity.
1. Immediately before handling any semiconductor
component or semiconductor-equipped assembly, drain
off any electrostatic charge on your body by touching a
known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device,
which should be removed to prevent potential shock
reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with
ES devices, place the assembly on a conductive
surface such as aluminum foil, to prevent electrostatic
charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or
unsolder ES devices.
4. Use only an anti-static type solder removal device.
Some solder removal devices not classified as "anti-
static" can generate electrical charges sufficient to
damage ES devices.
5. Do not use freon-propelled chemicals. These can
generate electrical charges sufficient to damage ES
devices.
6. Do not remove a replacement ES device from its
protective package until immediately before you are
ready to install it. (Most replacement ES devices are
packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable
conductive material).
7. Immediately before removing the protective material
from the leads of a replacement ES device, touch the
protective material to the chassis or circuit assembly
into which the device will be installed.
CAUTION: Be sure no power is applied to the chassis
or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or
the lifting of your foot from a carpeted floor can
generate static electricity sufficient to damage an ES
device.)

- 5 -
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and
appropriate tip size and shape that will maintain tip
temperature within the range or 500 F to 600 F.
2. Use an appropriate gauge of RMA resin-core solder
composed of 60 parts tin/40 parts lead.
3. Keep the soldering iron tip clean and well tinned.
4. Thoroughly clean the surfaces to be soldered. Use a
mall wire-bristle (0.5 inch, or 1.25cm) brush with a
metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal
temperature.
(500 F to 600 F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static,
suction-type solder removal device or with solder
braid.
CAUTION: Work quickly to avoid overheating the
circuitboard printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal
temperature (500 F to 600 F)
b. First, hold the soldering iron tip and solder the strand
against the component lead until the solder melts.
c. Quickly move the soldering iron tip to the junction of
the component lead and the printed circuit foil, and
hold it there only until the solder flows onto and
around both the component lead and the foil.
CAUTION: Work quickly to avoid overheating the
circuit board printed foil.
d. Closely inspect the solder area and remove any
excess or splashed solder with a small wire-bristle
brush.
IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong)
through which the IC leads are inserted and then bent flat
against the circuit foil. When holes are the slotted type,
the following technique should be used to remove and
replace the IC. When working with boards using the
familiar round hole, use the standard technique as
outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation
by gently prying up on the lead with the soldering iron
tip as the solder melts.
2. Draw away the melted solder with an anti-static
suction-type solder removal device (or with solder
braid) before removing the IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad
and solder it.
3. Clean the soldered areas with a small wire-bristle
brush. (It is not necessary to reapply acrylic coating to
the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by clipping its leads as
close as possible to the component body.
2. Bend into a "U" shape the end of each of three leads
remaining on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the
corresponding leads extending from the circuit board
and crimp the "U" with long nose pliers to insure metal
to metal contact then solder each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor
leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the
circuit board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close
as possible to diode body.
2. Bend the two remaining leads perpendicular y to the
circuit board.
3. Observing diode polarity, wrap each lead of the new
diode around the corresponding lead on the circuit
board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder
joints of the two "original" leads. If they are not shiny,
reheat them and if necessary, apply additional solder.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board
hollow stake.
2. Securely crimp the leads of replacement component
around notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the
replaced component and adjacent components and the
circuit board to prevent excessive component
temperatures.

- 6 -
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed
circuit board will weaken the adhesive that bonds the foil
to the circuit board causing the foil to separate from or
"lift-off" the board. The following guidelines and
procedures should be followed whenever this condition is
encountered.
At IC Connections
To repair a defective copper pattern at IC connections use
the following procedure to install a jumper wire on the
copper pattern side of the circuit board. (Use this
technique only on IC connections).
1. Carefully remove the damaged copper pattern with a
sharp knife. (Remove only as much copper as
absolutely necessary).
2. carefully scratch away the solder resist and acrylic
coating (if used) from the end of the remaining copper
pattern.
3. Bend a small "U" in one end of a small gauge jumper
wire and carefully crimp it around the IC pin. Solder the
IC connection.
4. Route the jumper wire along the path of the out-away
copper pattern and let it overlap the previously scraped
end of the good copper pattern. Solder the overlapped
area and clip off any excess jumper wire.
At Other Connections
Use the following technique to repair the defective copper
pattern at connections other than IC Pins. This technique
involves the installation of a jumper wire on the
component side of the circuit board.
1. Remove the defective copper pattern with a sharp
knife.
Remove at least 1/4 inch of copper, to ensure that a
hazardous condition will not exist if the jumper wire
opens.
2. Trace along the copper pattern from both sides of the
pattern break and locate the nearest component that is
directly connected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead
of the nearest component on one side of the pattern
break to the lead of the nearest component on the
other side.
Carefully crimp and solder the connections.
CAUTION: Be sure the insulated jumper wire is
dressed so the it does not touch components or sharp
edges.

TIMING CHART
- 7 -
VIDEO
SYNC
B
C
E
A
D
1 H(Pixels) + 25.175 31.469 800 640 16 96 48 640 x 400
V(Lines) - 70.09 449 350 37 2 60
2 H(Pixels) - 28.321 31.468 900 720 18 108 54 720 X 400
V(Lines) + 70.08 449 400 12 2 35
3 H(Pixels) - 25.175 31.469 800 640 16 96 48 640 x 480
V(Lines) - 59.94 525 480 10 2 33
4 H(Pixels) - 31.5 37.5 840 640 16 64 120 640 x 480
V(Lines) - 75 500 480 1 3 16
5 H(Pixels) + 40.0 37.879 1056 800 40 128 88 800 x 600
V(Lines) + 60.317 628 600 1 4 23
6 H(Pixels) + 49.5 46.875 1056 800 16 80 160 800 x 600
V(Lines) + 75.0 625 600 1 3 21
7 H(Pixels) +/- 57.283 49.725 1152 832 32 64 224 832 x 624
V(Lines) +/- 74.55 667 624 1 3 39
8 H(Pixels) - 65.0 48.363 1344 1024 24 136 160 1024 x 768
V(Lines) - 60.0 806 768 3 6 29
9 H(Pixels) - 78.75 60.123 1312 1024 16 96 176 1024 x 768
V(Lines) - 75.029 800 768 1 3 28
10 H(Pixels) +/- 100.0 68.681 1456 1152 32 128 144 1152 x 870
V(Lines) +/- 75.062 915 870 3 3 39
11 H(Pixels) +/- 92.978 61.805 1504 1152 18 134 200 1152 x 900
V(Lines) +/- 65.96 937 900 2 4 31
12 H(Pixels) + 108.0 63.981 1688 1280 48 112 248 1280 x 1024
V(Lines) + 60.02 1066 1024 1 3 38
MODE H / V Sync
Polarity
Dot
Clock Frequency Total
Period
( E )
Video
Active
Time ( A )
Sync
Duration
( D )
Front
Porch
( C )
Blanking
Time
( B ) Resolution

DISASSEMBLY
- 8 -
Hold the stand body & stand base.
1. Let the all latches are separated
2. Disassemble back cover.
Separate body & stand base.
Remove the screws.
# 1
# 4
# 2
# 3
Disassemble Connector.
# 5

BLOCK DIAGRAM
- 9 -
IR detector
5V
LVDS MODULE
MX25L4005A
(Serial Flash)
Control Board(Tact Switch)
LED
Speaker Left Speaker Right
TTL MODULE
15V 5V 15V 12V_Panel
5V 5V
15V
LIPS
RGB in
Audio out
Audio in
CVBS in
Video in
Audio in
Y in
C in
CVBS out
Control in/out
EEPROM
(24C64)
CVBS
Jack
S-Video
Jack
Stereo -In
(Option)
H/P
Output
LED / IR / Control
Power
Video
Audio
Dat a
Address Data
CLK,DQM, WEZ,CASZ,RASZ
EEPROM
(24C02)
M12L16161A -5TG
(SDRAM )
CVBS TunerCVBS Tuner
SCL/SDA
SCL/SDA
SCL/SDA
SIF_OUT
CVBS OUT
MST96585
(Scaler + Video Decoder)
SCART
Jack
D-Sub
(Option)
RS-232C
(Option)
Rx/Tx
CS4352
(DAC)
3.3V
12V
Regulator
Regulator
Regulator
Regulator
Regulator
5V 1.8V
LED/IR Board
Control
MX232A
(RS-232C)
ON/OFF
PWM_DIM
DIM _CTL
YDA1 38
(Audio amp)
Rx/Tx
FET Switch
(SI4925BDY)
5V
12V
IF_Video

DESCRIPTION OF BLOCK DIAGRAM
- 10 -
1. Power Supply Block (LIPS)
This Block Generates DC Voltage (5V,15V) to Main Control system from AC Power (100-240 V, 50/60 Hz, 1.0A)
Also it has the inverter function that converts input voltage to AC Rms value for the LCD lamp.
2. Voltage Regulator
Voltage regulator convert the input 5V,15V to proper 1.8V, 3.3V, 5V, 12V for Main control system.
For shooting heat trouble, we use the voltage regulator IC.
3. Digital Audio Amplifier
This block is composed of YDA138-EZ and peripheral device
The function of the audio amplifier is that to amplify audio L / R signal transmitted from audio decoder. The audio
signal is amplified according to pre-defined DC volume control curve.
4. Audio / Video Decoder / Scaler
This block is composed of LGE9655 and peripheral devices.
1) Video Decoder
This Block Selects input Video signals (like CVBS, Y/C, SCART RGB) and output LVDS/ TTL signal through
Scaler.
On decoding, We can control signal like Contrast, Brightness, Sharpness, Color, tint signals including
Adaptive Comb Filter.
2) Audio Decoder
This block analyzes audio input signal through A/V Jack (and PC audio) and Tuner SIF.
The analyzed signals transmitted to audio amplifier.
On decoding, We can control signal like Bass, treble.
3) Scaler
This IC includes A/D Converter and LVDS Transmitter
This IC is directly Inputted Analog Signal and transmits it to LCD Module
4) Micom
This block controls each IC through IIC communication line.
5. DAC IC (CS4352)
It is composed of CS4352.
The CS4352 is a complete stereo digital-to-analog system including digital interpolation, fifth-order multi-bit
delta-sigma digital-to-analog conversion, digital de-emphasis, analog filtering, and on-chip 2 Vrms line-level
driver.
6. TUNER
Micom controls this through IIC Line.
TUNER makes CVBS/SIF and transmits CVBS/SIF signal to LGE9655.

LIPS Board Block Diagram
- 11 -
EMI
COMPONENTS
LINE
100 ~ 240V
INPUT RECTIFIER
AND FILTER
ENERGY
TRANSFER
OUTPUT RECTIFIER
AND FILTER
12V
5V
GND
SIGNAL
COLLENT-
ION
PHOTO-
COUPLER
ISOLATI ON
HVDC 100KHz
PRIMARY SECONDARY
50 ~ 60Hz
PWM
COMTROL
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 for 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 achieve the dc output stabilized, 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.

ADJUSTMENT
- 12 -
Windows EDID V1.0 User Manual
Operating System: MS Windows 98, 2000, XP
Port Setup: Windows 98 => Don’t need setup
Windows 2000, XP => Need to Port Setup.
This program is available to LCD Monitor only.
1. Port Setup
a) Copy “UserPort.sys”file to
“c:\WINNT\system32\drivers”folder
b) Run Userport.exe
c) Remove all default number
d) Add 300-3FF
e) Click Start button.
f) Click Exit button.
2. EDID Read & Write
1) Run WinEDID.exe
2) Edit Week of Manufacture, Year of Manufacture,
Serial Number
a) Input User Info Data
b) Click “Update”button
c) Click “Write”button
If you don't write EDID, check below
1. Enter "SVC Menu" (refer 14page)
- Enter "Etc"
- Enter "Write Protect
1 : EDID protection (No write)
0 : EDID wirte
- Write EDID
2. Escape " SVC Menu" and push "In-stop" Button on SVC-Remote controller.

SERVICE OSD
- 13 -
Tool Option 8065
Area Option 04
OPTION 1 6
RAM Delay
OPTION 2 2
OPTION 3 2
OPTION 4 3
OPTION 5 9
ETC
BLUEBIRD3 - LP68A
Version 2.04 070129
UTT
M1721A SXGA LPL-17
0
Power Off History
Description of operation
- Tool Option : Adjust Tool Option
- Area Option : Adjust Area Option
- Option 1 : Adjust Tuner Service Option
- Option 2 : Adjust Sound Service Option
- Option 3 : Adjust Local key
- Option 4 : Select default language
- Option 5 : Adjust ETC
- RAM Delay : Adjust RAM Delay
- Power Off History : Adjust Power Off History
- ETC
How to enter SVC Menu
1. Push "Adjust" Key in SVC remote controller.
2. Push "Menu" Key in remote controller over 5 seconds the while pushing "Menu" key of Local button.
(If SVC OSD appear, remove the finger on "Menu" Key in remote controller first of all)
Figure 1. Cable Connection
220
IBM
Compatible PC
PARALLEL PORT
Power inlet (required)
Power LED
ST Switch
Power Select Switch
(110V/220V)
Control Line
Not used
RS232C
PARALLEL
V-SYNC POWER
ST
VGS MONITOR
E
E
V-Sync On/Off Switch
(Switch must be ON.)
F
F
A
A
B
B
C
C
15
10
5
5
69
1
1
1
14
13
25
6
5V
5V
5V
4.7K
4.7K
4.7K
74LS06
74LS06
OFF ON
OFF
ON
11
RGB(PC/DTV)IN
ANTENNAIN
AUDIO
(RGB)IN
H/PS-VIDEO
AVIN 2
AV1
(Mono)
VIDEO AUDIO
LR
Video Signal
Generator

TROUBLESHOOTING GUIDE
- 14 -
No power
(LED indicator off)
Check short of main B/D
or Change Lips
Change IC903
Change LED Assy
Check 15V or 5V
of Lips
Check Output of
IC903
Check LED Assy
Check P901, P270,
Connector.
Fail
Fail
Change Q904
Check Output of
Q904 Fail
Pass
Pass
Fail
Pass
Pass
Pass
:[A]Process

- 15 -
No Raster
Check LED Status
on display unit
Check the input/
Output of IC 100
Check
IC900, IC901, IC906, IC908,
IC909, IC910
Check inverter
Connector or inverter
Check inputting source
cable and jack.
Repeat A PROCESS
Fail
Change IC900, IC901,
IC906, IC908, IC909,
IC910
Fail
Change IC100
Fail
Change inverter
connector or inverter
Fail
Change panel link
cable or module
Fail
Check panel link
Cable or module
Pass
Pass
Pass
Pass
Pass
:[B]Process

- 16 -
No Raster on AV Signal
(Component, CVBS, S-VHS) No Raster on TV(RF) signal
Change R104, R106,
R108, R131, L822, L800,
L801
Check the signal of
R104, R106, R108, R131
L822, L800, L801
Repeat
[A] Process Check the output
of TU500
Check the
input/ output of IC100
Check input source cable and
jack
Fail
Fail Fail
Fail
Re-solder or change the
defect part.
Check X101
Check 5V of TU500.
Re-solder or change the
defect part
Pass
Pass
Pass
Pass

- 17 -
No Sound
Check the speaker wire
Change source input
Check the
input source Fail
Pass
Pass
Pass
Pass
Re-soldering or
Change the defect part
Check X301
Check the input/output
of IC100 Fail
Re-soldering or
Change the defect part
Check the input/output
of IC400 Fail
Change speaker
Check the speaker
Fail

WIRING DIAGRAM
- 18 -
30P
6631T900055A
5P
11P
6631T20038G
6631900042B
EAB32761501
3P
6631900024D

EXPLODED VIEW
- 19 -
300
510 440
120
200
530
520 430 500
174
410
400
900
920
910
930
420

EXPLODED VIEW PARTS LIST
- 20 -
120
174
200
300
400
410
420
430
440
500
510
520
530
900
910
920
930
EAB32761501
Speaker,Full Range, L07030A-027 ND35 3W 16OHM 85DB 300HZ 30 X 70 X 22 SOLDER SUNLINK COMPANY
6410TEW010A Power Cord, CEE,LP-34A&H05VV-FX3C,LS-60_1.87M_BLK LP-34A LS-60 1.87M NONE 250V 16A H05VV-F 3X0.75MM2 BLACK VDE SEMKO N LONGWELL COMPANY
EAJ36379501 LCD,Module-TFT, LM170E03-TLL2 DRIVER 17.0INCH 1280X1024 300CD COLOR 72% 4/3 800:1 P6, 5ms, 160/160, TLI T-con, Lusem/Lusem(Source/Gate), Diffuser x3, lamp wire 150mm
or EAJ36380701
LCD,Module-TFT, LM170E03-TLL3 DRIVER 17.0INCH 1280X1024 300CD COLOR 72% 4/3 800:1 P5, 5ms, 160/160, TLI T-con, Magna/Toshiba(Source/Gate), Diffuser x3, lamp wire 150m
EAJ36380901 LCD,Module-TFT, LM190E08-TLL2 DRIVER 19.0INCH 1280X1024 300CD COLOR 72% 4/3 800:1 P7, 5ms, 160/160, TLI T-con, Lusem/Lusem(Source/Gate), lamp Heesung, Diffuser x3, la
or EAJ36381001 LCD,Module-TFT, LM190E08-TLL3 DRIVER 19.0INCH 1280X1024 300CD COLOR 72% 4/3 800:1 P4, 5ms, 160/160, TLI T-con, Magna/Toshiba(Source/Gate), lamp Wooree ETI, Diffuser x
ABJ31008211 Cabinet Assembly, M1721A-BZH LP68A 17" CABINET ASSY,BK, PAL,BB#
ABJ31008113 Cabinet Assembly, M1921A LP-68A 19" CABINET ASSY, BK, MFT,PAL,SET,BB3 ANALOG
ACQ31008405
Cover Assembly,Rear, M1721A/17LS5R LP68A(BB3) 17" M1721A/17LS5R BACK COVER ASSY, RAVEN BLACK, BB3,ANALOG
ACQ31008309
Cover Assembly,Rear, M1921 CL-81 19" BACK COVER ASSY, RAVEN BLACK, BB3 analog, MFT,LPL TLL,SET
MEY32043301 Knob, MOLD ABS HF-350 SUB 7 KEY M1921 / M1721 ABS, BLACK
MGJ32111401 Plate,Shield, PRESS SBHG 0.6T METAL EGI M1721 INVERTER SHIELD
MGJ32111102 Plate,Shield, PRESS SBHG 0.6T METAL EGI M1921 INVERTER SHIELD FOR LPL MODULE
ADV31008019
Frame Assembly, M1721A-ZK(AUO)/17LS5R(AUO)/M1921A-ZK(LPL)/M1921A-ZK(LPL GIPS) LP68A(BB3) ETC METAL FRAME ASSY BB3, ANALOG
ADV31008041 Frame Assembly, M1921A-BZH BB3,PAL,ANALOG 19" LPL CI 6t
6620K00017C
Socket,Power, DAC-11S L3(ADD CORE) 3P STRAIGHT WIRE BK AC 40*22.5mm 10.0A 250.0V - DONG IL TECHNOLOGY LTD.
EBR31760603 PCB Assembly, CONTROL T.T LP68A LS1R-ZK SKD LS1R-ZK SKD
EBR32541805 PCB Assembly, SUB T.T CL81 Mx21A-BZH (FOR BB3 MAIN) LED+IR
EBU36608801 Main Total Assembly, M1721A-BZH BRAND LP68A
EBU36609101 Main Total Assembly, M1921A-BZH BRAND LP68A
6871TPT318G
PCB Assembly,Power, PLLM-M602B POWER T.T CMO L225W 22"Wide Scaler Dimming FREQENCY CHANGE LG INNOTEK CO., LTD
ACQ31008501 Cover Assembly, M1721/M1921 CL-81 ETC HINGE COVER ASSY, RAVEN BLACK
MCK32045601 Cover, MOLD ABS HF-350 M1921 / M1721 ABS STAND BODY, BLACK
MCK32045701
Cover, MOLD ABS HF-350 M1921 / M1721 ABS STAND HOLDER_CABLE ARRANGEMENT, BLACK
ACQ31009201 Cover Assembly, M1921 / M1721 CL-81 ETC STAND BASE COVER, RAVEN BLACK
Description
Part No.
Ref. No.
* Note: Safety mark