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LCD Projection TV
SERVICE MANUAL
CHASSIS : MB-03CB

MODEL : RT-52/60SZ31RB/RP
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.




Oct.,2003
P/NO : 3828VD0133Z Printed in Korea TV/AV MENU OK VOL PR ON/OFF
CONTENTS



CONTENTS ..................................................................................................................... 2

SAFETY PRECAUTIONS ................................................................................................3

SERVICING PRECAUTIONS .......................................................................................... 4

CONTROL DESCRIPTIONS ............................................................................................6

SPECIFICATIONS ..........................................................................................................10

ADJUSTMENT INSTRUCTIONS ....................................................................................14

BLOCK DIAGRAM..........................................................................................................20

PRINTED CIRCUIT BOARD ...........................................................................................25

EXPLODED VIEW .................................................................................................... 34,36

EXPLODED VIEW PARTS LIST ................................................................................35,37

REPLACEMENT PARTS LIST .......................................................................................38

SVC. SHEET ......................................................................................................................




- 2 -
SAFETY PRECAUTIONS

I M P O RTANT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in
the Schematic Diagram and Replacement Parts List.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to
prevent X-RADIATION, Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.



General Guidance Leakage Current Cold Check(Antenna Cold Check)
With the instrument AC plug removed from AC source,
An lsolation Transformer should always be used during connect an electrical jumper across the two AC plug prongs.
the servicing of a receiver whose chassis is not isolated from Place the AC switch in the on position, connect one lead of
the AC power line. Use a transformer of adequate power rating ohm-meter to the AC plug prongs tied together and touch other
as this protects the technician from accidents resulting in ohm-meter lead in turn to each exposed metallic parts such as
personal injury from electrical shocks. antenna terminals, phone jacks, etc.
If the exposed metallic part has a return path to the chassis, the
It will also protect the receiver and it's components from being measured resistance should be between 1M and 5.2M.
damaged by accidental shorts of the circuitry that may be When the exposed metal has no return path to the chassis the
inadvertently introduced during the service operation. reading must be infinite.
An other abnormality exists that must be corrected before the
If any fuse (or Fusible Resistor) in this TV receiver is blown, receiver is returned to the customer.
replace it with the specified.
Leakage Current Hot Check (See below Figure)
When replacing a high wattage resistor (Oxide Metal Film Plug the AC cord directly into the AC outlet.
Resistor, over 1W), keep the resistor 10mm away from PCB. Do not use a line Isolation Transformer during this check.
Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
Keep wires away from high voltage or high temperature parts. between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Due to high vacuum and large surface area of picture tube, Measure the AC voltage across the resistor using AC
extreme care should be used in handling the Picture Tube. voltmeter with 1000 ohm/volt or more sensitivity.
Do not lift the Picture tube by it's Neck. Reverse plug the AC cord into the AC outlet and repeat AC
voltage measurements for each exposed metallic part. Any
Before returning the receiver to the customer, voltage measured must not exceed 0.75 volt RMS which is
corresponds to 0.5mA.
always perform an AC leakage current check on the exposed In case any measurement is out of the limits specified, there is
metallic parts of the cabinet, such as antennas, terminals, etc., possibility of shock hazard and the set must be checked and
to be sure the set is safe to operate without damage of repaired before it is returned to the customer.
electrical shock.
Leakage Current Hot Check circuit

AC Volt-meter




Good Earth Ground
such as WATER PIPE,
To Instrument's CONDUIT etc.
0.15uF
exposed
METALLIC PARTS


1.5 Kohm/10W




- 3 -
S E RVICING PRECAUTIONS
CAUTION: Before servicing receivers covered by this service transistors and semiconductor "chip" components. The
manual and its supplements and addenda, read and follow the following techniques should be used to help reduce the
SAFETY PRECAUTIONS on page 3 of this publication. incidence of component damage caused by static by static
NOTE: If unforeseen circumstances create conflict between the eetiiy
lcrct.
following servicing precautions and any of the safety 1 Immediately before handling any semiconductor component
.
precautions on page 3 of this publication, always follow the or semiconductor-equipped assembly, drain off any
safety precautions. Remember: Safety First. electrostatic charge on your body by touching a known earth
ground. Alternatively, obtain and wear a commercially
General Servicing Precautions available discharging wrist strap device, which should be
1 Always unplug the receiver AC power cord from the AC
. removed to prevent potential shock reasons prior to
power source before; applying power to the unit under test.
a Removing or reinstalling any component, circuit board
. 2 After removing an electrical assembly equipped with ES
.
module or any other receiver assembly. devices, place the assembly on a conductive surface such as
b Disconnecting or reconnecting any receiver electrical plug
. aluminum foil, to prevent electrostatic charge buildup or
or other electrical connection. exposure of the assembly.
c Connecting a test substitute in parallel with an electrolytic
. 3 Use only a grounded-tip soldering iron to solder or unsolder
.
capacitor in the receiver. ES devices.
CAUTION: A wrong part substitution or incorrect 4 Use only an anti-static type solder removal device. Some
.
polarity installation of electrolytic capacitors may result solder removal devices not classified as "anti-static" can
in an explosion hazard. generate electrical charges sufficient to damage ES devices.
d Discharging the picture tube anode.
. 5 Do not use freon-propelled chemicals. These can generate
.
2 Test high voltage only by measuring it with an appropriate
. electrical charges sufficient to damage ES devices.
high voltage meter or other voltage measuring device (DVM, 6 Do not remove a replacement ES device from its protective
.
FETVOM, etc) equipped with a suitable high voltage probe. package until immediately before you are ready to install it.
Do not test high voltage by "drawing an arc". (Most replacement ES devices are packaged with leads
3 Discharge the picture tube anode only by (a) first connecting
. electrically shorted together by conductive foam, aluminum
one end of an insulated clip lead to the degaussing or kine foil or comparable conductive material).
aquadag grounding system shield at the point where the 7 Immediately before removing the protective material from
.
picture tube socket ground lead is connected, and then (b) the ieads of a replacement ES device, touch the protective
touch the other end of the insulated clip lead to the picture material to the chassis or circuit assembly into which the
tube anode button, using an insulating handle to avoid device will be installed.
personal contact with high voltage. CAUTION:Be sure no power is applied to the chassis or
4 Do not spray chemicals on or near this receiver or any of its
. circuit, and observe all other safety precautions.
assemblies. 8 Minimize bodily motions when handling unpackaged
.
5 Unless specified otherwise in this service manual, clean
. replacement ES devices. (Otherwise harmless motion such
electrical contacts only by applying the following mixture to as the brushing together of your clothes fabric or the lifting
the contacts with a pipe cleaner, cotton-tipped stick or of your foot from a carpeted floor can generate static
comparable nonabrasive applicator; 10% (by volume) electricity sufficient to damage an ES device.)
Acetone and 90% (by volume) isopropyl alcohol (90%-99%
strength) General Soldering Guidelines
CAUTION: This is a flammable mixture. 1 Use a grounded-tip, low-wattage soldering iron and
.
Unless specified otherwise in this service manual, lubrication appropriate tip size and shape that will maintain tip
of contacts in not required. temperature within the range or 500