LG DP381B User manual

PORTABLE DVD
SERVICE MANUAL
MODELS : DP381B, DP382B, DP383B
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.
MODELS : DP381B, DP382B, DP383B
SERVICE MANUAL
P/NO : AFN70285030 NOVEMBER, 2008
Website http://biz.lgservice.com
Internal Use Only

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 9V
Power consumption 13.5W
External dimensions 225 x 40 x 175mm (W x H x D)
Net Weight (Approx.) 1.06kg
Operating temperature: 5ºC to 40ºC
Operating humidity 5% to 90%
Laser Semiconductor laser
Signal system PAL
• CONNECTORS
Audio/Video Output ø3.5mm mini jack x 1
- Video: 1.0V(p-p), 75Ω, sync negative
- Audio: 2Vrms (1kHz, 0dB)
Earphone terminal ø3.5mm stereo mini jack x 2
• LIQUID CRYSTAL DISPLAY
Panel size 8.5 inches wide (diagonal)
Projection system R.G.B. stripe
Driving system TFT active matrix
Resolution 480 x 234 (WQVGA)
• ACCESSORIES
- RCA Video/Audio cable
- AC Adapter (IM090WU-150B)
- Automotive Adapter (G1000233)
- Remote Control
- Battery for Remote Control (Lithium Battery)
* Designs and specifications are subject to change without prior notice.

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
A
C
B
LCD BOARD
A
G
F
BC
K
USB BOARD
E
D
D
KEY BOARD
I
J
K
H
FG
MAIN BOARD
E
A48
A40
A42
A45
A46
A44
264
293
294
289
279
295
296
278
A51
251
251
277
272
277
271
270
252
288
450
286
254
294
256
450 450
282
285
809
287
452 288
451
452
453
454
450 450
261
CABLE2
CABLE1
255
255
266
455
455
260
266
451
H
J
I
A00
CABLE3
262
262
263
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
801 OWNER'S MANUAL
CABLE, CIGAR JACK
804 PACKING SHEET
835 CAR-MOUNT
808 BATTERY
803 PACKING
GIFT BOX
802A

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 ADJUSTMENTS ................................................................................................................................3-2
LCD ELECTRICAL TROUBLESHOOTING GUIDE .........................................................................3-3
BLOCK DIAGRAM......................................................................................................................................3-5
CIRCUIT DIAGRAM ...................................................................................................................................3-7
CIRCUIT VOLTAGE CHART ...................................................................................................................3-9
PRINTED CIRCUIT BOARD DIAGRAM............................................................................................3-10
MAIN PART ...............................................................................................................................................3-11
MAIN ELECTRICAL TROUBLESHOOTING GUIDE .....................................................................3-11
1. POWER (DC-DC CONVERTER) CIRCUIT..........................................................................................3-11
2. MPEG CIRCUIT ...................................................................................................................................3-14
3. SERVO CIRCUIT .................................................................................................................................3-15
4. CHARGING CIRCUIT ..........................................................................................................................3-17
WIRING CONNECTION DIAGRAMS..................................................................................................3-18
1. WIRING CONNECTION DIAGRAMS-1 ...............................................................................................3-18
2. WIRING CONNECTION DIAGRAMS-2 ...............................................................................................3-19
3. WIRING CONNECTION DIAGRAMS-3 ...............................................................................................3-20
BLOCK DIAGRAMS.................................................................................................................................3-21
1. OVERALL BLOCK DIAGRAM..............................................................................................................3-21
2. POWER BLOCK DIAGRAM.................................................................................................................3-22
3. SERVO BLOCK DIAGRAM..................................................................................................................3-23
4. SYSTEM BLOCK DIAGRAM................................................................................................................3-24
5. AV BLOCK DIAGRAM ..........................................................................................................................3-25
CIRCUIT DIAGRAMS ..............................................................................................................................3-27
1. POWER CIRCUIT DIAGRAM ..............................................................................................................3-27
2. AV CIRCUIT DIAGRAM........................................................................................................................3-29
3. CONNECTION CIRCUIT DIAGRAM....................................................................................................3-31
4. DC-DC CIRCUIT DIAGRAM ................................................................................................................3-33
5. MPEG CIRCUIT DIAGRAM .................................................................................................................3-35
6. SDRAM, FLASH & EEPROM CIRCUIT DIAGRAM .............................................................................3-37
CIRCUIT VOLTAGE CHART .................................................................................................................3-39
PRINTED CIRCUIT BOARD DIAGRAMS .........................................................................................3-43
1. MAIN P.C.BOARD ................................................................................................................................3-43
2. KEY P.C.BOARD ..................................................................................................................................3-47
3. USB P.C.BOARD..................................................................................................................................3-48

LCD PART
3-2 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
LCD ADJUSTMENTS
1) Power measuring
Measure each power after power supply.
CE38(+): 15V, CE41(-): -10V, CE50(+): 5V, CE49(+): 7.5V, C84(+): 3.5V,
CE47(+): 3.3V
2) VCOM DC level adjustment
Adjust the VCOM DC level by adjust the VR2.Make sure that the VCOM DC
level is between +1.9V and +2.4V.
GND
+2.15
Vcom Waveform

3-3
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? LED Backlight/Driver abnormal
NO
Appear shadow in
black backgroud
Power supply normal? Check main B/D and repairing
YES
NO
+5V normal? IC(U9) Check and Replace
YES
YES
NO
7.5V, 15V, -10V normal? D16, D17, D18, D19 Check and Replace
NO
RGB signal output? MTK1389P (Pin:184, 185, 187)
Check and Replace
YES
NO
IC(U8) Check and ReplaceVCOM signal? NO

3-4 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
LCD ELECTRICAL TROUBLESHOOTING GUIDE
YES
LCD TCON signal
normal? (ALL"LOW")
TFT LCD normal? Replace
Main B/D Check
YES
NO
NO
Color normal? Check RGB AMP circuit
(Q29, Q30, Q31) and Replace
YES
YES
NO
TFT LCD
Power supply voltage?
+15V, -10V, +5V
Power source, D16, D17, D18, D19
Check and Replace
NO
Each connector? Replace and Reassemble
YES
NO
ReplaceEND NO

BLOCK DIAGRAM
3-5
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
•STVR
•STVL
•CKV •UND •OEV •LNR •OEH •VCOMO •PWRCTL_LCD •STHR •STHL •CPH1 •89P_R •89P_G
•89P_B
•SP_R+ •SP_R- •SP_L+ •SP_L-- •LED_CTR •K2 •IR •BAT_OUT •PW R CT L _L C D
VCOM BLOCK
•NJM3414A IC LCD POWER BLOCK
•VG H (15V)
•VG L ( - 1 0V)
•8V •5V
•SS6608 IC
R/G/B AMP Circuit
•ROUT
•GOUT
•BOUT
•VCOM
•STVR •STVL •STHR •STHL •UND •LNR •CKV •OEV •OEH
•CPH1 •CPH2 •CPH3 •VCOM •VGH •VGL •89P_R •89P_G •89P_B
LCD PANEL
SPEAK
•SP L+ •SP L- •SP R+ •SP R-
BACKLIGHT
•BAT_OUT
•PWRCTL_LCD
•SSPT4105 IC
LED DRIVERCIRCUIT
Connector
(Main interface)
•3.3V •GND
KEY
•K2

3-6 Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
MEMO

3-7 3-8
CIRCUIT DIAGRAM
DC-DC
Friday, February 22, 2008
BAT_OUT
BAT_OUT
89P_R
OEH
STVL
89P_G
VCOMO
VCOM
VGL
BOUT
7VD5
CPH1
MCU 3.3V
VGL
VCOM
89P_G
CKV
MOD
STHR
3.3V
SP_L-
K2
89P_B
VGH
LNR
VGL
IR
ROUT
STHL
89P_B
UND
SP_L+
OEV
STHL
5VD
PWRCTL_LCD
GOUT
K2
89P_R
OEV
STHR
MCU 3.3V
3.3V
STVL
UND
IR
PWRCTL_LCD
CKV
OEH
STVR
CPH1
STVR
3.3VVCOMO
BOUT
VGH
ROUT
SP_R-
LED3.3V
GOUT
SP_R+
LNR
LED_CTR
3.3V LED3.3V
AMP_VDD
5VD
5VD
V_BIAS
V_BIAS
V_BIAS
3.3V
BAT_OU
T
V_BIAS
3.3V
AMP_VDD
AMP_VDD
AMP_VDD
C67
0.1uF
+ CE47
22uF/16V
+
CE39
10uF/16V
U8 CSC3414AM
1
2
3
4 5
6
7
8
AOUT
AIN-
AIN+
GND BIN+
BIN-
BOUT
VDD
C68
22pF
+ CE44
10uF/16V
R7 8K2/1%
R137
20K
C99
10uF/16V
Q31
3904
1
3 2
R8
1K
R6 13K/1%
+ CE48
10uF/25V
C61
0.1u
+
CE50
47uF/10V
R160
270
R10
NC
+
CE40
10uF/16V
R169
7.5K
R9
100
K
J6
CON26 AUO8.5'
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
+ CE45
10uF/16V
R168
1M
R139
100R
C59
0.1uF
C72
1uF
C62 1uF
R174
1K
J7
CON20
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
D21
LED
R136
15K
C78
0.1uF
R186
7.5K
+
CE52
10uF/16V
R177
270
U9
SS9
969
2
31
GND
IN OUT
+
CE38
10uF/25V
R187
75
C58
0.1uF
D24
LED
C1
0.1uF
D18
DA204
C80
100pF
C2
OPEN
R151
100
R159
20K
L32 18uH
L38 22uH
R153
100
Q32
390
6
1
32
C79
100pF
+
CE53
10uF/16V
D13 OPEN
C71
1uF
+ CE49
10uF/20V
S18
NEX
T
S15
PAUSE
D19
SSD03
C101 100PF
C83
100pF
VR2 10K
1 2
3
12
3
C50
1000pF
C74
0.1uF
+
CE56
10uF/16V
D17
DA204
L31 18uH
CE58
10uF/16V
R150
910
K
R178
910
K
D16
DA204
Q30
3904
1
3 2
+ CE46
10uF/16V
R172
1K
L1 600R
+ CE35
10uF/16V
R152
1M
R182
3R 0805
R188
100
K
R170
75
R145 33R
Q1 SSP04
03S
1
23
L34 22uH
+
CE51
10uF/16V
L39 1.8uH
R141
200
R132
100R
D23
LED
C77
0.1uF
U10
SS66
08
2
3
1 5
4
GND
FB
SW
IN
EN
R4 1K2/1%
R184
1M
R142 0
C76
0.1uF
R3 1K5/1%
R220
4.7K
R140 0
R2 2K/1%
R134
33K
R135
10R
L37 22uH
R1 3K/1%
R155
75
R191
10K
R143 NC
L35 1.8uH
+
CE55
10uF/16V
R133
10K
+
CE42
10uF/25V
R181
3R 0805
R189 1K
C64
1uF
R220
10R
R157
10K
R167
100
R149
270
R192
68K
C66 1uF
C86
100pF
R138 10K
C65
1uF
S16
PLAY
R148
20K
+ CE36
10uF/16V
R146 33R
+ CE37
10uF/16V
R180
3R 0805
D20
LED
L30 18uH
R179
3R 0805 C87
100pF
C81
100pF
IC2 IR RECEIVE
R
A
K
R154
7.5K
+ CE43
10uF/16V
Q29
3904
1
3 2
R173
1K
C70
22pF
C69
22pF
Q33
3904
1
3 2
CE57
10uF/16
L33 22uH
R218 10
R161
910
K
R171
1K
J9
CON18
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
U11 SSPT
4105
1
2
3
4 5
6
7
8
CE
NC
VIN
NC NC
LX
GND
FB
R190
10K
C75
0.1uF
S17
PREVIOUS
D26 SS1
4
R185
10K
C84
47/16V
D22
LED
+
CE54
10uF/16V
R5 0R
R183
100
C73
0.1uF
S14
STO
P
R156
51K
R175
1K
J10
CON2 1.25
1
2
L36 1.8uH
R131 100R
+
CE41
10uF/25V
R176
20K
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only

PRINTED CIRCUIT BOARD DIAGRAM
(TOP VIEW)
3-9 3-10
CIRCUIT VOLTAGE CHART
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
PIN NO. STOP PLAY
CE39
+1.51 1.51
--0.1 -0.1
CE40
+2.05 2.05
-0.43 0.43
CE47
+3.23 3.23
-00
CE49
+7.99 7.99
-00
CE50
+5.02 5.02
-00
CE51
+3.24 3.24
-2.58 2.58
CE52
+1.91 1.91
-0.44 0.44
CE53
+3.28 3.28
-2.59 2.59
CE54
+1.18 1.18
-0.44 0.44
CE55
+3.26 3.26
-2.59 2.59
CE56
+1.18 1.18
-0.44 0.44
C84
+3.58 3.58
-0.21 0.21
Q1
Emitter 3.3 3.3
Collector 0.01 0.01
Base 3.3 3.3
Q29
Emitter 0.5 0.5
Collector 3.24 3.24
Base 1.18 1.18
Q30
Emitter 0.49 0.49
Collector 3.27 3.27
Base 1.18 1.18
PIN NO. STOP PLAY
Q31
Emitter 0.49 0.49
Collector 3.26 3.26
Base 1.18 1.18
Q32
Emitter 1.01 1.01
Collector 1.02 1.02
Base 0.51 0.51
Q33
Emitter 0 0
Collector 0.04 0.04
Base 0.64 0.64
U8(NJM3414A)
10.42 0.42
200
300
4-11.59 -11.59
50.42 0.42
60.42 0.42
70.42 0.42
85.02 5.02
U9(SS9969)
188
200
35.02 5.02
U10(SS6608)
13.18 3.18
200
31.26 1.26
43.22 3.22
53.22 3.22
U11(SSPT4105)
11.02 1.02
24.98 4.98
34.98 4.98
44.98 4.98
53.63 3.63
63.63 3.63
70.2 0.2
80.2 0.2
(BOTTOM VIEW)

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
A
Replace ADAPTOR
NO
YES
1. POWER (DC-DC CONVERTER) CIRCUIT
A. POWER
Is ADAPTOR
out 9V
Replace F1
NO
YES
YES
Is F1 OK.
Replace U4 Replace
CON1 or CON2
No +3.3V No +5V No LCD powerNo +1.8V
YES
YES
NO Replace U4
Is U4
3.3V OK?
No power on
by BATTERY
A
Replace BATTERY
NO
YES
Is
BATTERY
OK?
YES
A