DP450G.pdf 데이터시트 (총 30 페이지) - 파일 다운로드 DP450G 데이타시트 다운로드

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P/NO : AFN73065026
MARCH, 2009
Internal Use Only
Website http://biz.lgservice.com
PORTABLE DVD
SERVICE MANUAL
MODEL : DP450G
CAUTION
BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”
IN THIS MANUAL.

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CONTENTS
SECTION 1.........SUMMARY
SECTION 2.........EXPLODED VIEWS
SECTION 3.........ELECTRICAL
SECTION 4.........REPLACEMENT PARTS LIST
1-1

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SECTION 1
SUMMARY
CONTENTS
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
1-2

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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 haz-
ard.These components are indicated by the letter “x” included in their compo-
nent designators and are required to maintain safe performance. No deviations
are allowedwithout 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 mod
fications 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 equi-
lateral triangle is intended to convey to the service personnel the
following fuse replacement caution notice:
CAUTION: FOR CONTINUED PROTECTION AGAINST RISK
OF FIRE, REPLACE ALLFUSES WITH THE SAME TYPE AND
RATING AS MARKED NEAR EACH FUSE.
GOOD EARTH
GROUND SUCH AS
THE WATER PIPE.
CONDUIT. ETC
A.C. VOLTMETER
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
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 fasteers 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. Aproduct 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 cast-
ers 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 conse-
quences to home and family.
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 co
ponents, 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. posed 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 re-
peat AC voltage measurements for each exposed metallic part. Voltage
measured must not exceed 0.75 volts RMS. This corresponds to 0.5 milli-
amp AC. Any value exceeding this limit constitutes a potential shock hazard
and must be corrected immediately.
1-3

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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 unfore-
seen 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) Disconnection or reconnecting any internal electrical
plug or other electrical connection.
(3) Connecting a test substitute in parallel with an electro-
lytic capacitor.
Caution : A wrong part substitution or incorrect polar-
ity 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. U nless 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
whitch 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 cerrectly installed.
6. Always connect test instrument ground lead to the ap-
propriate ground before connection 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 re-
sistance between each blade of the attachment plug and
accessible conductive parts (Note 1) should be more than
1Mohm.
Note 1 : Accessible Conductive Parts including Metal pan-
els, 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 compo-
nent or semiconductor-equipped assembly, drain off any
electrostatic charge on your body by touching a known
earth ground. Alternatively, obtain and wear a com-
mercially available discharging wrist strap device, which
should be removed for potential shock reasons prior to
applying power to the unit under test.
2. A fter 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. U se only a grouned-tip soldering iron to solder or unsol-
der ES devices.
4. U se only an anti-static solder removal device. Some sol-
der removal devices not classified a “anti-static” can gen-
erate electrical charges sufficient to damage ES devices.
5. D o not use freon-propelled chemicals. These can gener-
ate electrical charge sufficient to damage ES devices.
6. D o not remove a replacement ES device from its protec
tive package until immediately before you are ready to in-
stall 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 protec-
tive 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. M inimize bodily motions when handling unpackaged
replacement ES devices. (Normally harmless motion such
as the brushing together of your clothes fabric or the lift-
ing of your foot from a carpeted floor can generate static
electricity sufficient to damage an ES device.)
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