DAEWOO EKTVM14 Service Manual

SERVICE MANUAL

Color Television Receiver

Model: EKTVM14

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IMPORTANT SERVICE SAFETY INFORMATION

Operating the receiver outside of its cabinet or with its back removed involves a shock hazard. Work on these
models should only be performed by those who are thoroughly familiar with precautions necessary when working on
high voltage equipment.

Exercise care when servicing this chassis with power applied. Many B plus and high voltage RF terminals are
exposed which, if carelessly contacted, can cause serious shock or result in damage to the chassis. Maintain
interconnecting ground lead connections between chassis, escutcheon, picture tube dag and tuner when operating
chassis.

These receivers have a “polarized” AC line cord. The AC plug is designed to fit into standard AC outlets in one
direction only. The wide blade connects to the “ground side” and the narrow blade connects to the hot “side” of the AC
line. This assures that the TV receiver is properly grounded to the house wiring. If an extension cord must be used, make
sure it is of the “polarized” type.

Since the chassis of this receive is connected to one side of the AC supply during operation, service should not be
attempted by anyone not familiar with the precautions necessary when working on these types of equipment.

When it is necessary to make measurements or tests with AC power applied to the receiver chassis, an Isolation
Transformer must be used as a safety precaution and to prevent possible damage to transistors. The Isolation
Transformer should be connected between the TV line cord plug and the AC power outlet.

Certain High voltage (HV) maybe cause X-ray radiation. Receivers should not be operated with HV levels
exceeding the specified rating for their chassis type. Higher voltage may also increase the possibility of failure in the HV
supply.

It is important to maintain specified values of all components in the horizontal and high voltage circuits and
anywhere else in the receive that could cause a rise in high voltage, or operating supply voltages. No changes should be
made the original design of the receiver.

Components shown in the shaded areas on the schematic diagram and/or identified by in the replacement parts list
should be replaced only with exact factory recommended replacement parts. The use of unauthorized substitute parts
man creats may create shock, fire, X-ray radiation, or other hazards.

To determine the presence of high voltage, use an accurate high impedance HV meter connected between the
second anode lead and he CRT dag grounding device. When servicing the High Voltage System remove static charges
from it by connecting a 10K Ohm resistor in series Wan insulated wire(such as test probe) between the picture tube dag
and 2nd anode lead(Have AC line cord disconnected from AC supply).

The picture tube use in this receiver employ integral implosion protection. Replace with a tube of the same type
number for continued safety. Do not lift picture tube by the neck. Handle the picture tube only when wearing
shatterproof goggles and after discharging the high voltage completely, Keep others without shatter proof goggles away.

Before returning the receiver to the user, perform the following safety checks:

1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not lodged between the

chassis and other metal parts in the receiver.

2. Replace all protective devices such as non-metallic control knobs, insulating fishpapers, cabinet backs,

adjustment and compartment covers of shiedls, isolation resistor-capacitor networks, mechanical insulators etc.

3. To be sure that not shock hazard exists, a check for the presence of leakage current should be made at each

exposed metal part having a return path to the chassis (antenna, cabinet metal, screw heads knobs and/or shafts,
escutcheon, etc.) in the following manner.

Plug the AC line cord directly into a 120V, AC receptacle. (Do not use an Isolation Transformer during these
checks.) All checks must be repeated with the AC line cord plug connection reversed. (If necessary, a nonpolarized

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adapter plug must be used only for the purpose of completing these checks.)

If available, measure current using an accurate leakage current tester. Any reading of 0.35mA or more is excessive
and indicates a potential shock hazard which must be corrected before returning the receiver to owner.

If a reliable leakage current tester is not available, this allernate method of measurement should be used. Using
two clip leads, connect a 1500 Ohm, 10 watt resistor paralleled by a 0.15MF capacitor in series with a known earth
ground, such as a water pipe or conduit and the metal part to be checked. Use a VTVM or VOM with 1000 Ohms per
Volt, or higher, sensitivity to measure this AC voltage drop across the resistor,. Any reading of 0.35 volt RMS of more is
excessive and indicates potential shock hazard which must be corrected before returning he receiver to the owner.

ALIGNMENT PROCEDURES

PLEASE READ BEFORE ATTEMPTING SERVICE

1. Use an Isolation Transformer when performing any service on this chassis.

2. Never disconnect any leads while receiver is in operation.

3. Disconnect all power before attempting an repairs.

4. Do not short any position of the circuit while the power is on.

5. For safety reasons, replacing any components should be according with identical replacement parts (SEE

PARTS LIST).

6. Before testing, warm up the TV for at least 30 minutes and demagnetize the CRT with an external degaussing

coil.

7. When removing a PCB or related component, after unfastening or changing a wire, be sure to put the wire back

in its original position.

8. Inferior silicon grease can damage IC’s and transistors. When replacing IC’s and transistors, use only specified

silicon grease,. Remove all old silicon when applying new silicon.

9. Before removing the anode cap, discharge eiecticity because it contains high voltage.

TEST EQUIPMENT

1. Oscilloscope

2. Multi-meter (Internal resistance: DC≥20kΩ/V AC≥5kΩ/V）

3. High voltmeter 35kV

4. Ammeter (0.5 rating, at DC 3mA position)

5. Degaussing coil

6. PT5820 signal generator

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