LG DP351G User manual

PORTABLE DVD
SERVICE MANUAL
MODEL: DP351G
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
MODEL: DP351G
SERVICE MANUAL
P/NO : AFN56903641
Website http://biz.lgservice.com
Internal Use Only
APRIL, 2008
Av. Sor Juana lnés de la Cruz No 555
Col. San Lorenzo
Tlalnepantla, Estado de México CP 54033
Tel. [phone] Fax. [phone]
Lada sin costo 01 800 50 481 00

Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
CONTENTS
SECTION 1.........SUMMARY
SECTION 2.........EXPLODED VIEWS
SECTION 3.........ELECTRICAL
SECTION 4.........REPLACEMENT PARTS LIST

SECTION 1
SUMMARY
CONTENTS
1-2 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS .............................1-3
SERVICING PRECAUTIONS....................................................................................................................1-4
• GENERAL SERVICING PRECAUTIONS
• INSULATION CHECKING PRODEDURE
• ELECTROSTATICALLY SENSITIVE (ES) DEVICES
SPECIFICATIONS ........................................................................................................................................1-5

1-3
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS
IMPORTANT SAFETY NOTICE
This manual was prepared for use only by properly trained audio-video service
technicians.
When servicing this product, under no circumstances should the original design be
modified or altered without permission from LG Corporation. All components should be
replaced only with types identical to those in the original circuit and their physical
location, wiring and lead dress must conform to original layout upon completion of
repairs.
Special components are also used to prevent x-radiation, shock and fire hazard.
These components are indicated by the letter “x” included in their component
designators and are required to maintain safe performance. No deviations are allowed
without prior approval by LG Corporation.
Circuit diagrams may occasionally differ from the actual circuit used. This way,
implementation of the latest safety and performance improvement changes into the set
are not delayed until the new service literature is printed.
CAUTION : Do not attempt to modify this product in any way. Never perform
customized installations without manufacturer’s approval. Unauthorized modifications
will not only void the warranty, but may lead to property damage or user injury.
Service work should be performed only after you are thoroughly familiar with these
safety checks and servicing guidelines.
GRAPHIC SYMBOLS
The exclamation point within an equilateral triangle is intended to alert
the service personnel to important safety information in the service
literature.
The lightning flash with arrowhead symbol within an equilateral triangle
is intended to alert the service personnel to the presence of noninsulated
“dangerous voltage” that may be of sufficient magnitude to constitute a
risk of electric shock.
The pictorial representation of a fuse and its rating within an equilateral
triangle is intended to convey to the service personnel the following fuse
replacement caution notice:
CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF
FIRE, REPLACE ALL FUSES WITH THE SAME TYPE AND RATING
AS MARKED NEAR EACH FUSE.
SERVICE INFORMATION
While servicing, use an isolation transformer for protection from AC line shock. After the
original service problem has been corrected, make a check of the following:
FIRE AND SHOCK HAZARD
1. Be sure that all components are positioned to avoid a possibility of adjacent
component shorts. This is especially important on items trans-ported to and from the
repair shop.
2. Verify that all protective devices such as insulators, barriers, covers, shields, strain
reliefs, power supply cords, and other hardware have been reinstalled per the
original design. Be sure that the safety purpose of the polarized line plug has not
been defeated.
3. Soldering must be inspected to discover possible cold solder joints, solder splashes,
or sharp solder points. Be certain to remove all loose foreign particles.
4. Check for physical evidence of damage or deterioration to parts and components,
for frayed leads or damaged insulation (including the AC cord), and replace if
necessary.
5. No lead or component should touch a high current device or a resistor rated at 1 watt
or more. Lead tension around protruding metal surfaces must be avoided.
6. After reassembly of the set, always perform an AC leakage test on all exposed
metallic parts of the cabinet (the channel selector knobs, antenna terminals, handle
and screws) to be sure that set is safe to operate without danger of electrical shock.
DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS TEST. Use an
AC voltmeter having 5000 ohms per volt or more sensitivity in the following manner:
Connect a 1500 ohm, 10 watt resistor, paralleled by a .15 mfd 150V AC type
capacitor between a known good earth ground water pipe, conduit, etc.) and the
exposed metallic parts, one at a time. Measure the AC voltage across the
combination of 1500 ohm resistor and .15 mfd capacitor. Reverse the AC plug by
using a non-polarized adaptor and repeat AC voltage measurements for each
exposed metallic part. Voltage measured must not exceed 0.75 volts RMS. This
corresponds to 0.5 milliamp AC. Any value exceeding this limit constitutes a potential
shock hazard and must be corrected immediately.
TIPS ON PROPER INSTALLATION
1. Never install any receiver in a closed-in recess, cubbyhole, or closely fitting shelf
space over, or close to, a heat duct, or in the path of heated air flow.
2. Avoid conditions of high humidity such as: outdoor patio installations where dew is a
factor, near steam radiators where steam leakage is a factor, etc.
3. Avoid placement where draperies may obstruct venting. The customer should also
avoid the use of decorative scarves or other coverings that might obstruct ventilation.
4. Wall- and shelf-mounted installations using a commercial mounting kit must follow
the factory-approved mounting instructions. A product mounted to a shelf or platform
must retain its original feet (or the equivalent thickness in spacers) to provide
adequate air flow across the bottom. Bolts or screws used for fasteners must not
touch any parts or wiring. Perform leakage tests on customized installations.
5. Caution customers against mounting a product on a sloping shelf or in a tilted
position, unless the receiver is properly secured.
6. A product on a roll-about cart should be stable in its mounting to the cart.
Caution the customer on the hazards of trying to roll a cart with small casters across
thresholds or deep pile carpets.
7. Caution customers against using extension cords. Explain that a forest of
extensions, sprouting from a single outlet, can lead to disastrous consequences to
home and family.

1-4 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SERVICING PRECAUTIONS
CAUTION: Before servicing the PORTABLE DVD covered by
this service data and its supplements and addends, read and
follow the SAFETY PRECAUTIONS. NOTE: if unforeseen
circumstances create conflict between the following servicing
precautions and any of the safety precautions in this
publication, always follow the safety precautions.
Remember Safety First :
General Servicing Precautions
1. Always unplug the PORTABLE DVD AC power cord from
the AC power source before:
(1) Removing or reinstalling any component, circuit board,
module, or any other assembly.
(2) Disconnecting or reconnecting any internal electrical
plug or other electrical connection.
(3) Connecting a test substitute in parallel with an
electrolytic capacitor.
Caution: A wrong part substitution or incorrect polarity
installation of electrolytic capacitors may result in an
explosion hazard.
2. Do not spray chemicals on or near this PORTABLE DVD or
any of its assemblies.
3. Unless specified otherwise in this service data, clean
electrical contacts by applying an appropriate contact
cleaning solution to the contacts with a pipe cleaner, cotton-
tipped swab, or comparable soft applicator.
Unless specified otherwise in this service data, lubrication of
contacts is not required.
4. Do not defeat any plug/socket B+ voltage interlocks with
which instruments covered by this service manual might be
equipped.
5. Do not apply AC power to this PORTABLE DVD and / or any
of its electrical assemblies unless all solid state device heat
sinks are correctly installed.
6. Always connect the test instrument ground lead to an
appropriate ground before connecting the test instrument
positive lead. Always remove the test instrument ground
lead last.
Insulation Checking Procedure
Disconnect the attachment plug from the AC outlet and turn
the power on. Connect an insulation resistance meter (500V)
to the blades of the attachment plug. The insulation resistance
between each blade of the attachment plug and accessible
conductive parts (Note 1) should be more than 1Mohm.
Note 1: Accessible Conductive Parts include Metal panels,
Input terminals, Earphone jacks,etc.
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 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 for 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 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
an electrical charge 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. (Normally 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.)

1-5
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SPECIFICATIONS
• GENERAL
Power requirements DC 12V
Power consumption 12W
External Dimensions 202 x 39 x 164mm (W x H x D)
Net Weight (Approx.) 0.85kg
Operating temperature: 5ºC to 40ºC
Operating humidity 5% to 90%
Laser Semiconductor laser
Signal system NTSC
• CONNECTORS
Audio/Video Output ø3.5mm mini jack x 1
- Video: 1.0V(p-p), 75Ω, sync negative
- Audio: 1.5Vrms (1kHz, 0dB)
Earphone terminal ø3.5mm stereo mini jack x 1
• LIQUID CRYSTAL DISPLAY
Panel size 7 inches wide (diagonal)
Projection system R.G.B. stripe
Driving system TFT active matrix
Resolution 480 x 234 (WQVGA)
• SUPPLIED ACCESSORIES
- RCA Video/Audio cable
- AC Adapter (MPA-630)
- Automotive Adapter (DPDC1)
- Remote Control
- Battery for Remote Control (Lithium Battery)

1-6 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MEMO

2-1
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SECTION 2
EXPLODED VIEWS
CONTENTS
EXPLODED VIEWS .....................................................................................................................................2-2
1. CABINET AND MAIN FRAME SECTION ..................................................................................................2-2
2. PACKING ACCESSORY SECTION...........................................................................................................2-3

2-2 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
J
K
HI
B
E
C
D
I
L
K
J
L
D
A
G
C
B
E
A
F
F
GH
293 295
296
277
253
272
277
A52
A45
288
288
264
278
297
262
263
809
285
285
286
282
CABLE1
CABLE2
CABLE3
281
289
A44
A00
A46
283
A48
A43
A40
A53
LCD
LCD PANEL
KEY
MAIN
A51
262
251
251A
287
EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION

2-3
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PACKING ACCESSORY SECTION
PLUG ASS'Y(RCA CABLE)
806
834
ADAPTER
833
REMOTE CONTROL
900
BOX
802
BOX
802A
808 BATTERY
801 OWNER'S MANUAL
CABLE, CIGAR JACK
804 PACKING SHEET
803 PACKING
BOX
802B

2-4 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MEMO

3-1
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
SECTION 3
ELECTRICAL
CONTENTS
LCD PART ...................................................................................................................................................3-2
LCD ELECTRICAL TROUBLESHOOTING GUIDE .........................................................................3-2
BLOCK DIAGRAM......................................................................................................................................3-3
CIRCUIT DIAGRAM ...................................................................................................................................3-5
PRINTED CIRCUIT BOARD DIAGRAM..............................................................................................3-7
MAIN PART ...............................................................................................................................................3-11
MAIN ELECTRICAL TROUBLESHOOTING GUIDE .....................................................................3-11
1. DC-DC CONVERTER CIRCUIT...........................................................................................................3-11
2. MPEG CIRCUIT ...................................................................................................................................3-14
3. RF/SERVO CIRCUIT............................................................................................................................3-15
4. CHARGING CIRCUIT ..........................................................................................................................3-18
DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING .................................3-19
1. SYSTEM 27MHz CLOCK, RESET & FLASH R/W SIGNAL ................................................................3-19
2. SDRAM CLOCK ...................................................................................................................................3-19
3. DISC TYPE JUDGEMENT WAVEFORM .............................................................................................3-20
4. FOCUS ON WAVEFORM.....................................................................................................................3-22
5. SPINDLE CONTROL WAVEFORM (NO DISC CONDITION)..............................................................3-22
6. TRACKING CONTROL RELATED SIGNAL (SYSTEM CHECKING) ..................................................3-23
7. MT1389 AUDIO OPTICAL AND COAXIAL OUTPUT (ASPDIF) ..........................................................3-24
8. MT1389 VIDEO OUTPUT WAVEFORM ..............................................................................................3-24
9. AUDIO OUTPUT FROM AUDIO DAC..................................................................................................3-25
WIRING CONNECTION DIAGRAMS..................................................................................................3-26
1. WIRING CONNECTION DIAGRAMS-1 ...............................................................................................3-26
2. WIRING CONNECTION DIAGRAMS-2 ...............................................................................................3-27
BLOCK DIAGRAMS.................................................................................................................................3-29
1. OVERALL BLOCK DIAGRAM..............................................................................................................3-29
2. POWER BLOCK DIAGRAM.................................................................................................................3-31
3. SERVO BLOCK DIAGRAM..................................................................................................................3-33
4. SYSTEM BLOCK DIAGRAM................................................................................................................3-35
5. AV BLOCK DIAGRAM ..........................................................................................................................3-37
CIRCUIT DIAGRAMS ..............................................................................................................................3-39
1. MPEG CIRCUIT DIAGRAM .................................................................................................................3-39
2. MEMORY CIRCUIT DIAGRAM ............................................................................................................3-41
3. OPU & MOTOR CIRCUIT DIAGRAM ..................................................................................................3-43
4. AV CIRCUIT DIAGRAM........................................................................................................................3-45
5. CHARGE CIRCUIT DIAGRAM.............................................................................................................3-47
6. LCD I/F CIRCUIT DIAGRAM................................................................................................................3-49
7. KEY MENU CIRCUIT DIAGRAM .........................................................................................................3-51
• CIRCUIT VOLTAGE CHART ..............................................................................................................3-53
PRINTED CIRCUIT BOARD DIAGRAMS .........................................................................................3-57
1. MAIN P.C.BOARD ................................................................................................................................3-57
2. KEY MENU P.C.BOARD ......................................................................................................................3-61

LCD PART
3-2 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
LCD ELECTRICAL TROUBLESHOOTING GUIDE
YES
Display condition? Inverter abnormal
NO
Appear shadow form
interference in black background
Fuse normal? Fuse Replace
YES
NO
+7.5V, 15V, -10V D906, D901, D902
YES
NO
+5V normal? IC(U902) Check and Replace
YES
NO
R G B signal output? Check and Replace
MPEG1389LP (Pin107, 108, 109)
YES
NO
VCOM signal?
(Vip 4.5) IC(U901) Check and Replace
YES
NO
LCD MODE
CONT signal? All “LOW” (Normal
condition?)
MAIN B/D Check
YES
NO
TFT LCD
pressure voltage? +3.3V, +5V,
+15V, -10V
Power source and
L9020R, L901, D901, D902 check
YES
NO
TFT LCD normal? Replace
YES
NO
Color
adjusting normal? Readjust as adjustement standard
YES
NO
Each connector? Replace and Reassemble
YES
NO
END Replace
NO

3-3 3-4
BLOCK DIAGRAM
•STVR
•STVL
•CKV
•UND
•OEV
•VCOMO
•OEH
•STHL
•CPH1
•89P_R
•89P_G
•89P_B
•SP L-
•SP L+
•SP R-
•SP R+
•3.3V
•5VA
•VIN_6-12V
•PWRCTL_LCD
•IR
•KEY-PLAY
•DVD_KEY1
•DVD_KEY2
•DVD_KEY3
•DVD_KEY4
•DVD_KEY5
•VCOM
•UTC3308 IC
Connector
(Main interface)
VCOM BLOCK
LCD POWER BLOCK
R/G/B Circuit
BLOCK
LCD PANEL
SPEAK
KEY
INVERTER POWER BLOCK
BACKLIGHT
KEYPAD BLOCK
IR
KEY-PLAY
DVD_KEY1
DVD_KEY2
DVD_KEY3
DVD_KEY4
DVD_KEY5
•ROUT
•GOUT
•BOUT
•VIN_6-12V
•PWRCTL_LCD
•MP2359 IC
•VGH (+15V)
•VGL (-10V)
•7.5V
•5V
•VGH
•VGL
•STVR
•STVL
•CKV
•UND
•OEV
•VCOMO
•LNR
•MOD
•OEH
•STHL
•STHR
•CPH3
•CPH2
•CPH1
•89P_R
•89P_G
•89P_B
•SP L-
•SP L+
•SP R-
•SP R+
•RCR2561 IC
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

3-5 3-6
CIRCUIT DIAGRAM
Friday, November 30, 2007Friday, November 30, 2007Friday, November 30, 2007
ROUT
BOUT
ROUT
BOUT
GOUT
STHR
OEH
STHL
OEV
UND
CKV
STVL
STVR
CPH1
LNR
+15V
+7.5V
IR
89L_B
5VA
DVD_KEY4
R_IN
89L_G
DVD_KEY1
KEY_PLAY
B_IN
IR
DVD_KEY2
G_IN
89L_R
-10V
GND
BIAS
89L_G
89L_B
GND
CPH1
STVL
STHL
LCD_3.3V
89L_R
OEV
VCOMO
5VA
GND
LCD_3.3V
CKV
OEH
SP_R-
SP_R+
DVD_KEY5
SP_L-
DVD_KEY3
SP_L+
5VD
5VD
7VD5
VCOMO
+7.5V
-10V
VCOM
VCOM
LCD_3.3V
R_IN
G_IN
GOUT
B_IN
KEY_PLAY
DVD_KEY1
DVD_KEY3
DVD_KEY5 DVD_KEY4
5VD
UND
5VD
LNR
DVD_KEY2
PWRCTL_LCD
SP_L-
SP_R+
SP_R-
SP_L+
VIN_6-12V
PWRCTL_LCD
GND
VIN_6-12V
GND
GND
5VD
LCD_3.3V
BIAS
BIAS
7VD5
7VD5
BIAS7VD5
Vdc
Vdc
Vdc
GND
CPH3
STHR
STHL
CKV
U/D
CPH1
VCOM
VCOM
OEV
VGL
VR
GND
VCC
VCC
L/R
VGH
VG
STVR
MOD
VB
AVSS
AVDD
CPH2
OEH
STVL
1.Ref
2.Anode
3.Cathode
123
89P VCOM DAC OUTPUT
Spec Sheet No.
DC TO DC
RCR2561
10
4
16
14
19
11
6
20
15
13
12
17
2
23
5
3
22
18
9
8
7
24
1
21
25
26
CPT CLAA070WA03
InnoLux AT070TN04
AUO A070FW03
Elite Star LR070WA01B
PVI PW070XU3
LED DRIVER
411.26
0603 to 0805(11.26)
0603 to 0805(11.26)
UTC3308
K905PLAYK905PLAY
1 2
D903
BAT54S
D903
BAT54S
3
2
1
C936ESD(15pF) C936ESD(15pF)
CN904
3.5-2P
CN904
3.5-2P
1
1
2
233
44
C953
104
C953
104
R935
4.7K
R935
4.7K
IR G VCC
IR901
HRM538CB5100 DIP
IR G VCC
IR901
HRM538CB5100 DIP
1 2 3
CN902
CON20_0.8MM
CN902
CON20_0.8MM
10
9
8
7
6
5
4
3
2
1
11
13
12
15
14
16
20
19
18
17
21
22
R919
160
R919
160
C940ESD(15pF) C940ESD(15pF)
K902NEXTK902NEXT
1 2
C938ESD(15pF) C938ESD(15pF)
C950 105C950 105
C954 10uF/16VC954 10uF/16V
R943
100/75
R943
100/75
C907 4.7u/25uFC907 4.7u/25uF
R927
47K
R927
47K
D901
D_15V
D901
D_15V
1 2
B
C
E
Q903
SMBT3904
B
C
E
Q903
SMBT3904
1
3 2
TP913TP913
C946 10uF/16VC946 10uF/16V
C961
104
C961
104
R928
160
R928
160
C924
105
C924
105
C919
22uF/16V
C919
22uF/16V
R952
6.8 1%
R952
6.8 1%
R911 0R911 0
R930
0R
R930
0R
R953
NC
R953
NC
C960
2.2uF/16V X5R
C960
2.2uF/16V X5R
C956
100pF
C956
100pF
R904
30K
R904
30K
R903
10K
R903
10K
D902
D_10V
D902
D_10V
1 2
R945
100K
R945
100K
D905
BAT54S
D905
BAT54S
3
2
1
R936
100
R936
100
R933
0R
R933
0R
C928
100pF
C928
100pFC927
104
C927
104
R950
5.6K
R950
5.6K
R926
430/270
R926
430/270
R944
10K
R944
10K
C947
100pF
C947
100pF
U901
NJM3414AM
U901
NJM3414AM
A OUT
1
A- IN
2
A+ IN
3
GND
4B+ IN 5
B- IN 6
B OUT 7
V+ 8
K901PLAUSEK901PLAUSE
1 2
TP912TP912
R939
47K
R939
47K
R946
10K
R946
10K
R913 NCR913 NC
R910 0R910 0
D906
1N5819
D906
1N5819
1 2
C930
22uF/10V
C930
22uF/10V
U904
MP2359DT
U904
MP2359DT
IN
5
EN
4
GND
2
BST 1
FB 3
SW 6
C934
100pF
C934
100pF
C923
104
C923
104
R905
10K
R905
10K
C913
104
C913
104
L9020RL9020R
TP921TP921
C943
100pF
C943
100pF
TP918TP918
D908
D_13V
D908
D_13V
1 2
C959
334
C959
334
C951
10uF/16V
C951
10uF/16V
TP920TP920
R923
100/75
R923
100/75
C949
100pF
C949
100pF
D907
SS14
D907
SS14
1 2
C906 4.7u/25uFC906 4.7u/25uF
TP919TP919
R902 2KR902 2K
C941
104
C941
104
C917
105
C917
105
R912 NCR912 NC
C952
20pF
C952
20pF
U903
MP1540
U903
MP1540
IN 5
SW 1
EN
4
GND
2
FB 3
TP916TP916
C915
104
C915
104
L908LSS57S30-330(33uH)L908LSS57S30-330(33uH)
L906
1.8uH
L906
1.8uH
C911
104
C911
104
R914
10K
R914
10K
R937
39k
R937
39k
TP909TP909
C921
22uF/16V
C921
22uF/16V
C935ESD(15pF) C935ESD(15pF)
C933
(NC)104
C933
(NC)104
C903
104
C903
104
D904
BAT54S
D904
BAT54S
3
2
1
C904 10uF/16VC904 10uF/16V
C937ESD(15pF) C937ESD(15pF)
C909 105C909 105
B
C
E
Q902
SMBT3904
B
C
E
Q902
SMBT3904
1
3 2
C925 105C925 105
C942
10uF/16V
C942
10uF/16V
TP914TP914
R915
39k
R915
39k
R942
10K
R942
10K
R916
430/270
R916
430/270
L9036.8uHL9036.8uH
R909
330
R909
330
R951
68K
R951
68K
R918
20K
R918
20K
C908
4.7uF/25V
C908
4.7uF/25V
R934
NC
R934
NC
L901 4.7uHL901 4.7uH
R917
47K
R917
47K
R908
TBD/10K
R908
TBD/10K
CN905
CON12_0.8MM
CN905
CON12_0.8MM
11
22
33
44
55
66
77
88
99
10 10
11 11
12 12
13
13 14
14
R925
39K
R925
39K
R932
100/75
R932
100/75
C916
104
C916
104
C955
103
C955
103
R901
6.8K
R901
6.8K
R940
160
R940
160
C926
104
C926
104
C902
10uF/16V
C902
10uF/16V
R931
10K
R931
10K
C905 10uF/16VC905 10uF/16V
R929
NC
R929
NC
B
C
E
Q901
SMBT3904
B
C
E
Q901
SMBT3904
1
3 2
R921
51K
R921
51K
TP915TP915
K904STOPK904STOP
1 2
R906
20K
R906
20K
R938
430/270
R938
430/270
C929
104
C929
104
+
C920
47uF/10V
+
C920
47uF/10V
12
R948
1K
R948
1K
R907
10K
R907
10K
C948
100pF
C948
100pF
K903PREK903PRE
1 2
C939ESD(15pF) C939ESD(15pF)
C944
100pF
C944
100pF
TP917TP917
R949
10K
R949
10K
C922
22uF/16V
C922
22uF/16V
U902
78L05
U902
78L05
GND
2
IN
3OUT 1
TP911TP911
R922
10K
R922
10K
R941
0R
R941
0R
B
C
E
Q904
SMBT3906
B
C
E
Q904
SMBT3906
2 3
1
C957
104
C957
104
VR901
10K
VR901
10K
1
2
3
CN901
CON26_0.5MM
CN901
CON26_0.5MM
10
9
8
7
6
5
4
3
2
1
11
13
12
15
14
16
20
19
18
17
24
23
22
21
26
25
27
28
C932 10uF/16VC932 10uF/16VC931
100pF
C931
100pF
C912 105
C912 105
R920
10K
R920
10K
C958
2.2uF/16V X5R
C958
2.2uF/16V X5R
C914
104
C914
104
C910 105C910 105
B
C
E
Q905
SMBT3904
B
C
E
Q905
SMBT3904
1
3 2
R947
270K
R947
270K
R924
10K
R924
10K
C918
104
C918
104
C901
10uF/16V
C901
10uF/16V
TP910TP910
L905 4.7uHL905 4.7uH
L907
1.8uH
L907
1.8uH
C945 105C945 105
L904
1.8uH
L904
1.8uH
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

3-7 3-8
PRINTED CIRCUIT BOARD DIAGRAM
(TOP VIEW)
(BOTTOM VIEW)
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MEMO

3-9 3-10 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MEMO MEMO

3-11
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MAIN PART
MAIN ELECTRICAL TROUBLESHOOTING GUIDE
No power on
by ADAPTOR
No +18V No LCD_3.3V
No S3.3V
No A+5V
No M5V
VCC_5V
No 5VA
Replace ADAPTOR
NO
YES
1. DC-DC CONVERTER CIRCUIT
Is ADAPTOR
out 12V?
Replace D606
NO
YES
Is D606 OK?
Is U202 1.8V OK?
Replace U401
NO
Replace U202
NO
YES
Is U401
3.3V OK?
Is Q402 5V OK?
Replace U401
NO
Replace U202
NO
YES
Is U401
5V OK?
No power on
by BATTERY
Replace BATTERY
NO
YES
Is BATTERY OK?
Replace U401
NO Is U401
5V OK?
A. NO POWER ON BY ADAPTOR B. NO POWER ON BY BATTERY

3-12 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Picture abnormal
Check the disc.
YES
YES
Refer to SERVO part
YES
Check DCLK signal of MPEG part
YES
Check MPEG (IC U201)
YES
Replace B/D
E. PICTURE ABNORMAL
Disc error
Check Disc
YES
YES
Refer to SERVO part
YES
Replace B/D
F. DISC ERROR
Audio out abnormal
Check Audio jack & mode
YES
YES
Check A+5V
YES
Check signals from MPEG
YES
Replace IC(U502)
MAIN ELECTRICAL TROUBLESHOOTING GUIDE
C. AUDIO OUT ABNORMAL
Video out abnormal
Check Video jack & mode
YES
YES
Check A+5V
YES
Check signals from MPEG
YES
Check IC(U502)
D. VIDEO OUT ABNORMAL

3-13
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
OPEN/CLOSE abnormal
Check SW201, SW202 switch
Refer to SERVO part.
YES
YES
Check IC(U201) Pin92 Check the connectin of MD.
YES
Refer to SERVO part.
YES
NO
MAIN ELECTRICAL TROUBLESHOOTING GUIDE
G. OPEN/CLOSE ABNORMAL