Daewoo CM 003 Service Manual

S/G No. : CM003P-010G1

Service Guide

Color Television

CHASSIS : CM-003
Model :

DTH-14V1FS
DTH-20V1FS
DTH-21V1FS
DTH-14V3FS
DTH-20V3FS
DTH-21V3FS
DTH-14V4FS
DTH-20V4FS
DTH-21V4FS

DTH-14V1FC

DTH-14V3FC

Features

181CH quartz frequency synthesis tuning system
On-Screen Display(Simple Icon Type/Trilingual : Eug/Span/Fre n)
Programmable channel skip memory
24 hour programmable TV on/off function
Convenient sleep timer
Built-in Closed Caption
Full function infrared remote control

DTH-20V4FC

POWER

MUTE

CH

VOLVOL

CH

DISPLAY INPUT VIDEO

1 2 3

4 5 6

7 809

SLEEP PREVIOUS

R-38T01

Specifications

Model Name

Screen Size 14" 20" 21"

Channel Coverage

Power Source
Power Consumption

Set Dimensions
(W H D)
Net Weight

Stuffing Q'th(48ft)

DTH-14V1/V3/V4FS DTH-20V1/V3/V4FS DTH-21V1/V3/V4FS

VHF 2-13
UHF 14-69
113 Cable Ch.

AC 100-260, 50/60Hz AC 100-260, 50/60Hz AC 100-260, 50/60Hz

63W 70W 73W

336 x 338 x 376(mm)

8.7Kg 16.3Kg 19Kg
1100Set 540Set

VHF 2-13
UHF 14-69
113 Cable Ch.

VHF 2-13
UHF 14-69
113 Cable Ch.

516x469(6)(4)x482(6)(2)(mm)496x446(2)(2)x464(4)(3)(mm)

DAEWOO ELECTRONICS CO., LTD

http : //svc.dwe.co.kr

Sep. 1999

Important Service Notes

1. X-ray Radiation Rrecaution

1) Excessive high voltage can produce potentially hazardous X-RAY RADIA­TION. To avoid such hazards, the high voltage must not be above the spec­ified limit. The nominal value of the high voltage of this receiver is

25.5kv(20”/21”) & 23.5kv(14”)at zero beam current (minimum brightness)
under a 120V/220V AC power source. The high voltage must not, under any
circumstances, exceed 28kv(20”/21”) & 26kv(14”). Each time a receiver
requires servicing, the high voltage should be checked following the HIGH
VOLTAGE CHECK procedure on page 10 of this manual. It is recom­mended as a parts of the service record. It is important to use an accurate
and reliable high voltage meter.

2) This receiver is equipped with X-RADIATION PROTECTION circuit which
prevents the receiver from producing an excessively high voltage even if the
B+voltage increases abnormally. Each time the receiver is serviced, X­RADIATION PROTECTION circuit must be checked to determine that the
circuit is properly functioning, following the X-RADIATION PROTECTION
CIRCUIT CHECK procedure on page 6 of this manual.

3) The only source of X-RAY RADIATION in this TV receiver is the picture tube.
For continued X-RAY RADIATION protection, the replacement tube must
be exactly the same type tube as specified in the parts list.

4) Some parts in this receiver have special safety-related characteristics for X­RAY RADIATION protection. For continued safety, parts replacement
should be undertaken only after referring to the PRODUCT SAFETY
NOTICE below.

2. Safety Precaution

WARNING: Service should not be attempted by anyone unfamiliar with the
necessary precaution on this receiver. The following are the necessary precau­tion to be observed before servicing.

1) Since the chassis of this receiver has hazardous potential to ground when­ever the receiver is plugged in (floating chassis), an isolation transformer
must be used during servicing to avoid shock hazard.

2) Always discharge the picture tube anode to the CRT conductive coating the
picture tube. The picture tube is highly evacuated and if broken, glass frag­ments will be violently expelled. Use shatterproof goggles and keep picture
tube away from the body while handling.

3) When placing chassis in the cabinet, always be certain that all the protective
devices are put back in place, such as; nonmetallic control knobs, insulat­ing covers, shields, isolation resistor-capacitor network, etc.

4) Before returning the set to the customer, always perform an AC leakage cur­rent check on the exposed metallic parts of the cabinet, such as antennas,
terminals, screw-heads, metal overlays, control shafts etc. to be sure the set
is safe to operate without danger of electrical shock. Plug the AC line cord
directly into a 120V AC outlet (do not use a line isolation transformer during
this check). Use an AC voltmeter having 5000 ohms per volt or more sensi­tivi-ty in the following manner.

Connect at 1500 ohm 10 watt resistor, paralleled by a 0.15 mfd. 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 0.15 mfd capacitor. Volt­age measured must not exceed 0.3 volts RMS. This corresponds to 0.2 mill­liamp. AC. Any value exceeding the limit constitutes a potential shock
hazard and must be corrected immediately.

AC VOLT METER

0.15MFD

Place this probe
on each exposed
metallic part.

Good earth ground
such as d water
pipe, conduit, etc.

1500 ohm
10watt

3. Product Safety Notice

Many electrical and mechanical parts in this chassis have special safety-related
characteristics. These characteristics are often passed unnoticed by a visual
inspection and the protection afforded by them cannot necessarily be obtained
by using replacement components rated for higher voltage, wattage, etc.
Replacement parts which have these special safety characteristics are identi­fied in this manual and its supplements; electrical components having such fea­tures are identified by shading on the schematic diagram and the parts list.
Before replacing any of these components, read the parts list in this manual
carefully. The use of substitute replacement parts which do not have the same
safety characteristics as specified in the parts list may create X-ray radiation or
other hazards.

4. Service Notes

1) When replacing parts or circuit boards, clamp or bend the lead wires to termi­nals before soldering.

2) When replacing a high wattage resistor (metal oxide film resistor) in the cir­cuit board, keep the resistor min 1/2 inch away form circuit board.

3) Keep wires away from high voltage or high temperature components.

DAEWOO ELECTRONICS CO., LTD.

C.P.OBOX8003 SEOUL, KOREA
Tel : [phone]
Fax : [phone]
E-mail : [e-mail]
Printed in Nov. 1998