Text preview for : CN-794N.pdf part of Daewoo CN-794N Daewoo Ñhassis CN CN-794N CN-794N.pdf
Back to : CN-794N.pdf | Home
S/M No : TCN794NEF0-R1
Service Manual
COLOR TELEVISION
CHASSIS : CN-794N
Model : DTQ-29U1SC/SSP
DTQ-29U5SC/SSP
DTQ-29U1SC DTQ-29U1SC
Caution
: In this Manual, some parts can be changed for improving. their
performance without notice in the parts list. So, if you need the
latest parts information, please refer to PPL(Parts Price List)in
Service Information Center(http://svc.dwe.co.kr)
DAEWOO ELECTRONICS Corp.
http : //svc.dwe.co.kr June. 2003
TABLE OF CONTENTS
SAFETY PRECAUTIONS 2
SPECIFICATIONS 5
CIRCUIT BLOCK DIAGRAM 6
ALIGNMENT INSTRUCTIONS 7
YOUR REMOTE CONTROL 7
SERVICE MODE ADJUSTMENT 8
ASSEMBLY ADJUSTMENT 10
SCHEMATIC DIAGRAM 13
ELECTRICAL PARTS LIST 17
DIFFERENT PARTS LIST 36
EXPLODE VIEW 37
PRINTED CIRCUIT BOARD 39
APPENDIX(Appendix is provide only by internet[http://svc.dwe.co.kr])
IC DESCRIPTION 49
WAVEFORMS 55
TROUBLE SHOOTING GUIDE 58
NO POWER 58
NO PICTURE 59
NO SOUND 60
CH DON T STOP 61
NO COLOR 62
NO VERTICAL DEFLECTION 62
NO ON-SCREEN DISPLAY 63
NO REMOCON RECEIPT 63
-1-
SAFETY PRECAUTIONS
CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN ANY WAY. SUBJECT : X-RADIATION
NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFAC-
TURER'S APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLY VOID 1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PERSON-
THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANT RESULT- NEL COVER THE SUBJECT OF X-RADIATION. THE ONLY POTENTIAL
ING PROPERTY DAMAGE OR USER INJURY. SOURCE OF X-RAYS IN CURRENT T.V. RECEIVERS IS THE PICTURE TUBE.
SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU ARE THOR- HOWEVER, THIS TUBE DOES NOT EMIT X-RAYS WHEN THE HIGH VOLT-
OUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETY CHECKS AND AGE IS AT THE FACTORY SPECIFIED LEVEL. THE PROPER VALUE IS GIVEN
SERVICING GUIDELINES. TO DO OTHERWISE, INCREASES THE RISK OF IN THE APPLICABLE SCHEMATIC. OPERATION AT HIGHER VOLT-AGES MAY
POTENTIAL HAZARDS AND INJURY TO THE USER. CAUSE A FAILURE OF THE PICTURE TUBE OR HIGH VOLTAGE SUPPLY
WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTECTION
AND UNDER CERTAIN CIRCUMSTANCES, AMY PRODUCE RADIA-TION IN
FROM A.C. LINE SHOCK.
EXCESS OF DESIRABLE LEVELS.
2. ONLY FACTORY SPECIFIED C.R.T ANODE CONNECTORS MUST BE
SAFETY CHECKS
USED.DEGAUSSING SHIELDS ALSO SERVE AS X-RAY SHIELD IN COLOR
AFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN CORRECTED, A CHECK SETS. ALWAYS RE-INSTALL THEM.
SHOULD BE MADE OF THE FOLLOWING: 3. IT IS ESSENTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE AN ACCU-
RATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRATION OF THE
SUBJECT:FIRE & SHOCK HAZARD METER SHOULD BE CHECKED PERIODICALLY AGAINST A REFERENCE
STANDARD. SUCH AS THE ONE AVAILABLE AT YOUR DISTRIBUTOR.
1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN SUCH A WAY AS 4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPERLY THERE
TO AVOID POSSIBILITY OF ADJACENT COMPONENT SHORTS. THIS IS IS NO POSSIBILITY OF AN X-RADIATION PROBLEM. EVERY TIME A COLOR
ESPECIALLY IMPORTANT ON THOSE MODULES WHICH ARE TRANS- CHASSIS IS SERVICED, THE BRIGHTNESS SHOULD BE RUN UP AND DOWN
PORTED TO AND FROM THE REPAIR SHOP. WHILE MONITORING THE HIGH VOLTAGE WITH A METER TO BE CERTAIN
2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE DEVICES SUCH AS THAT THE HIGH VOLTAGE DOES NOT EXCEED THE SPECIFIED VALUE AND
INSULATORS, BARRIERS, COVERS, SHIELDS, STRAIN RELIEFS, POWER THAT IT IS REGULATING CORRECTLY. WE SUGGEST THAT YOU AND YOUR
SUPPLY CORDS, AND OTHER HARDWARE HAVE BEEN REINSTALLED PER SERVICE ORGANIZATION REVIEW TEST PROCEDURES SO THAT VOLTAGE
ORIGINAL DESIGN. BE SURE, THAT THE SAFETY PURPOSE OF THE REGULATION IS ALWAYS CHECKED AS A STANDARD SERVICING
POLARIZED LINE PLUG HAS NOT BEEN DEFEATED. PROCEDURE, AND THAT THE HIGH VOLTAGE READING BE RECORDED ON
3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE COLD SOL- EACH CUSTOMER S INVOICE.
DER JOINTS, SOLDER SPLASHES OF SHARP SOLDER POINTS. BE CER- 5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS IN A
TAIN TO REMOVE ALL LOOSE FOREIGN PARTICLES.
PRODUCT WITH A PROBLEM OF EXCESSIVE HIGH VOLTAGE, AVOID BEING
4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR DETERIORATION TO
UNNECESSARILY CLOSE TO THE PICTURE TUBE AND THE HIGH VOLTAGE
PARTS AND COMPONENTS, FOR FRAYED LEADS, DAMAGED INSULATION
SUPPLY. DO NOT OPERATE THE PRODUCT LONGER THAN IS NECESSARY
(INCLUDING A.C. CORD), AND REPLACE IF NECESSARY. FOLLOW ORIGI-
NAL LAYOUT, LEAD LENGTH AND DRESS. TO LOCATE THE CAUSE OF EXCESSIVE VOLTAGE.
5. NO LEAD OR COMPONENT SHOULD TOUCH A RECEIVING TUBE OR A 6. REFER TO HV, B+ AND SHUTDOWN ADJUSTMENT PROCEDURES
RESISTOR RATED AT 1 WATT OR MORE. LEAD TENSION AROUND PRO- DESCRIBED IN THE APPROPRIATE SCHEMATIC AND DIAGRAMS (WHERE
TRUDING METAL SURFACES MUST BE AVOIDED. USED).
6. ALL CRITICAL COMPONENTS SUCH AS FUSES, FLAMEPROOF RESISTOR,
CAPACITORS, ETC. MUST BE REPLACED WITH EXACT FACTORY TYPES. SUBJECT : IMPLOSION
DO NOT USE REPLACEMENT COMPONENTS OTHER THAN THOSE SPECI-
FIED OR MAKE UNRECOMMENDED CIRCUIT MODIFICATIONS. 1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTEGRA
7. AFTER RE-ASSEMBLY OF THE STE ALWAYS PERFORM AN A.C. LEAKAGE IMPLOSION PROTECTION SYSTEM. BUT CARE SHOULD BE TAKEN TO
TEST ON ALL EXPOSED METALLIC PARTS OF THE CABINET. (THE CHAN- AVOID DAMAGE DURING INSTALLATION. AVOID SCRATCHING THE TUBE.
NEL SELECTOR KNOB, ANTENNA TERMINALS, HANDLE AND SCREWS) TO OF SCRATCHED REPLACE IT.
BE SURE THE SET IS SAFE TO OPERATE WITHOUT DANGER OF ELECTRI- 2. USE ONLY RECOMMENDED FACTORY REPLACEMENT TUBES.
CAL SHOCK. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS
TEST USE AN A.C. VOLTMETER, HAVING 5000 OHMS PER VOLT OR MORE SUBJECT : TIPS ON PROPER INSTALLATION
SENSITIVITY, IN THE FOLLOWING MANNER : CONNECT A 1500 OHM 10
WATT RESISTOR, PARALLELED BY A .15 MFD. 150V A.C. TYPE CAPACI- 1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBYHOLE OR
TOR BETWEEN A KNOWN GOOD EARTH GROUND (WATER POPE, CON- CLOSELY FITTING SHELF SPACE, OVER OR CLOSE TO HEAT DUCT, OR IN
DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME.
THE PATH OF HEATED AIR FLOW.
MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500 OHM
2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIO
RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUG AND
INSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIATORS
REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED METALLIC
PART. VOLTAGE MEASURED MUST NOT EXCEED .75 VOLTS R.M.S THIS WHERE STEAM LEAKAGE IS A FACTOR, ETC.
CORRESPONDS TO 0.5 MILLIAMP A.C. NAY VALUE EXCEEDING THIS LIMIT 3. AVOID PLACEMENT WHERE DRAPERIES MAY OBSTRUCT REAR VENTING.
CONSTITUTES A POTENTIAL SHOCK HAZARD AND MUST BE CORRECTED THE CUSTOMER SHOULD ALSO AVOID THE USE OF DECORATIVE
IMMEDIATELY. SCARVES OR OTHER COVERINGS WHICH MIGHT OBSTRUCT VENTILA-
TION.
4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMERCIAL
MOUNTING KIT, MUST FOLLOW THE FACTORY APPROVED MOUNTING
A.C. VOLTMETER
INSTRUCTIONS. A PRODUCT MOUNTED TO A SHELF OR PLATFORM MUST
RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENT THICKNESS IN SPAC-
ERS)TO PROVIDE ADEQUATE AIR FLOW ACROSS THE BOTTOM, BOLTS OR
SCREWS USED FOR FASTENERS MUST NOT TOUCH ANY PARTS OR
WIRING. PERFORM LEAKAGE TEST ON CUSTOMIZED INSTALLATIONS.
0.15 uF
5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ON
SLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT IS
GOOD EARTH GROUND PLACE THIS PROBE
SUCH AS THE WATER 1500 OHM
ON EACH EXPOSED
PROPERLY SECURED.
PIPE, CONDUIT, ETC.
10WATT METAL PART 6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITS MOUNT-
ING TO THE CART. CAUTION THE CUSTOMER ON THE HAZARDS OF TRY-
SUBJECT : GRAPHIC SYMBOLS ING TO ROLL A CART WITH SMALL CASTERS ACROSS THRESHOLDS OR
THE LIGHTNING FLASH WITH ARROWHEAD SYMBOL, DEEP PILE CARPETS.
WITHIN AN EQUILATERAL TRIANGLE, IS INTENDED TO 7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STAND WHICH
ALERT THE SERVICE PERSONNEL TO THE PRES-ENCE HAS NOT BEEN LISTED BY UNDERWRITERS LABORATORIES. INC. FOR
OF UNINSULATED DANGEROUS VOLTAGE USE WITH THEIR SPECIFIC MODEL OF TELEVISION RECEIVER OR
THAT MAY BE OF SUFFICIENT MAGNITUDE TO CON- GENERICALLY APPROVED FOR USE WITH T.V.S OF THE SAME OR LARGER
STITUTE A RISK OF ELECTRIC SHOCK. SCREEN SIZE.
8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS,
THE EXCLAMATION POINT WITHIN AN EQUILATERAL EXPLAIN THAT A FOREST OF EXTENSIONS SPROUTING FROM A SINGLE
TRIANGLE IS INTENDED TO ALERT THE SERVICE OUTLET CAN LEAD TO DISASTROUS CONSEQUENCES TO HOME AND
PERSONNEL TO THE PRESENCE OF IMPORTANT FAMILY.
SAFETY INFORMATION ON SERVICE LITERATURE.
-2-
SAFETY PRECAUTIONS
CAUTION : Do not attempt to modify this product in any way. Unau- The lightning flash with arrowhead symbol,
thorized modifications will not only void the warranty, but may lead to your within an equilateral triangle, is intended to alert
being liable for any resulting property damage or user injury. the service personnel to the presence of uninsu-
Service work should be performed only after you are thoroughly familiar lated dangerous voltage that may be of suffi-
with all of the following safety checks and servicing guide-lines. To do cienty magnitude to constitute a risk of electric
otherwise, increases the risk of potential hazards and injury to the user. shock.
SAFETY CHECKS The exclamation point within an equilateral tri-
angle is intended to alert the service personnel
After the original service problem has been corrected, a check should be to the presence of important safety information
made of the following: in service literature.
SUBJECT : FIRE & SHOCK HAZARD Fuse symbol is printed on pcb adjacent to the
fuse, with RISK OF FIRE REPLACE FUSE AS
1. Be sure that all components are positioned in such a way as to avoid MARKED . The symbol is explained in the ser-
possibility of adjacent component shorts. This is especially important on vice manual with the following wording or equiv-
those chassis which are transported to and from the repair shop. alent.
2. Never release a repair unless all protective devices such as insula-tors,
barriers, covers, shields, strain reliefs, and other hardware have been CAUTION : FOR CONTINUED PROTECTION AGAINST FIRE
reinstalled per original design. HAZARD, REPLACE ONLY WITH SAME TYPE (4A, 125V) and
3. Soldering must be inspected to discover possible cold solder joints, ATTENTION: AFIN D ASSU UNE PROTECTION PERMANENTE
frayed leads, damaged insulation (including A.C. cord), solder splashes CONTRE LES RISQUES D INCENDIE, REMPLACER UNIQUE-MENT
or sharp solder points. Be certain to remove all loose for-eign particals. PAR UN FUSIBLE DE MEME TYPE ET DE 4A, 125V .
4. Check for physical evidence of damage or deterioration to parts and
components, and replace if necessary follow original layout, lead length SUBJECT : X-RADIATION
and dress.
5. No leads or components should touch a receiving tube or a resistor 1. Be sure procedures and instructions to all service personnel cover
rated at 1 watt or more. Lead tension around protruding metal sur-faces the subject of X-rays in current T.V. receivers is the picture tube.
must be avoided. However, this tube does not emit X-rays when the high voltage is at
6. All critical components such as fuses, flameproof resistors, capaci-tors, the factory specified level. The proper value is given in the appli-
etc. must be replaced with exact factory types. Do not use replacement cable schematic. Operation at higher voltages may cause a failure
components other than those specified or make unrecommended circuit of the picture tube or high voltage supply and, under certain cir-
modifications. cumstances, may produce radiation in excess of desirable levels.
7. After re-assembly of the set always perform an A.C. leakage test on all 2. Only factory specified C.R.T. anode connectors must be used.
exposed metallic parts of the cabinet, (the channel selector knob, Degaussing shields also serve as X-ray shield in color sets. Always
antenna terminals, handle and screws) to be sure the set is safe to re-install them.
operate without danger of electrical shock. Do not use a line isolation 3. It is essential that the serviceman has available an accurate and
transformer during this test. Use an A.C. voltmeter, having 5000 ohms reliable high voltage meter. The calibration of the meter should be
per volt or more sensitivity, in the following manner : connect a 1500 checked perio - dically against a reference standard. Such as the
ohm 10 watt resistor, paralleled by a 15 mfd. 150V A.C. type capacitor one available at your distributor.
between a known good earth ground (9water pipe, conduit, etc.) and 4. When the high voltage circuitry is operating properly there is no
the exposed metallic parts, one at a time. Measure the A.C. voltage possibility of an X-radiation problem. Every time a color chassis is
across the combination of 1500 ohm resistor and 0.15 MFD capacitor. serviced, the brightness should be run up and down while monitor-
Reverse the A.C. plug and repeat A.C. voltage measurements for each ing the high voltage with a meter to be certain that the high voltage
exposed metallic part. Voltage measured must not exceed 0.75 volts does not exceed the specified value and that it is regulating cor-
R.M.S. This corresponds to 0.5 milliamp A.C. Any value exceeding this rectly. We suggest that you and your service organization review
limit constitutes a potential shock hazard and must be corrected imme- test procedures so that voltage regulation is always checked as a
diately. standard servicing procedure. And that the high voltage reading be
recorded on each customer s invoice.
5. When troubleshooting and making test measurements in a receiver
with a problem of excessive high voltage, avoid being unnecessarily
close to the picture tub eand the high voltage compartment. Do not
A.C. VOLTMETER operate the chassis longer than is necessary to locate the cause of
excessive voltage.
6. Refer to HV, B+and Shutdown adjustment procedures described in
the appropriate schematic and diagrams(where used).
0.15 uF
GOOD EARTH GROUND PLACE THIS PROBE
SUCH AS THE WATER 1500 OHM
ON EACH EXPOSED
PIPE, CONDUIT, ETC. METAL PART
10WATT
-3-
SAFETY PRECAUTIONS
SUBJECT : IMPLOSION 4. Wall and shelf mounted installations using a commercial mounting
kit, must follow the factory approved mounting instructions. A
1. All direct viewed picture tubes are equipped with an integral implo- receiver mounted to a shelf or platform must retain its original
sion protection system, but care should be taken to avoid damage feet(or the equivalent thickness in spacers) to provide adequate are
during installation. Avoid scratching the tube. If scratched, replace flow across the bottom, bolts or screws used for fasteners must not
it. touch and parts or wiring. Perform leakage test on cus-tomized
2. Use only recommended factory replacement tubes. installations.
5. Caution customers against the mounting of a receiver on sloping
SUBJECT : TIPS ON PROPER INSTALLATION shelf or a tilted position, unless the receiver is properly secured.
6. A receiver on a roll-about cart should be stable on its mounting to
1. Never install any receiver in closed-in recess, cubbyhole or closely the cart. Caution the customer on the hazards of trying to roll a cart
fitting shelf space over, or close to heat duct, or in the path of with small casters across thresholds or deep pile carpets.
heated air flow. 7. Caution customers against the use of a cart or stand which has not
2. Avoid conditions of high humidity such as : Outdoor patio installa- been listed by underwriters laboratories, inc. For use with their
tions where dew is a factor. Near steam radiators where steam specific model of television receiver or generically approved for use
leakage is a factor, etc. with T.V. s of the same or larger screen size.
3. Avoid placement where draperies may obstruct rear venting. The
customer should also avoid the use of decorative scarves or other
coverings which might obstruct ventilation.
-4-
SPECIFICTION
Model
DTQ-29U1/U5SC DTQ-29U1/U5SSP
Item
CHASSIS CN-794N
TV Standard NTSC-M
Power Input AC 120v, 60Hz
Power Consumption 112W
Tuning System Frequency Synthesizer(FS) Tuning System
Tuning Ranges TV VHF(L) : CH2 - CH6
UHF(H) : CH7 - CH13
UHF : CH14 - CH69
CATV VHF(L) : 5A, A,B,A-5-A-1
CH2-CH6
VHF(H) : C-W+11
CH7 - CH13
UHF : W+12-W+84
Sound Output 5W + 5W 7W + 7W
Speaker 8 ohm 7W x 2EA 8 ohm 15W x 2EA
Antenna Input Impedance 75 ohm Unbalanced
Auxiliary Input Terminal Side : Video, Audio(L,R) - AV2
Rear : Video, Audio(L,R) - AV1
S-Video
Y, Cb, Cr, Audio(L,R) - CVI
Auxiliary Output Terminal Rear : Video, Audio(L,R) - MONITOR OUT
Intermediate Frequencies Picture IF Carrier Frequency : 45.75MHz
Sound IF Carrier Frequency : 41.25MHz
Color Sub-Carrier Frequency : 3.579545MHz
Remote Control R-43A07
Special Function 1) Closed Caption
2) V-Chip
3) Channel Label
-5-
CIRCUIT BLOCK DIAGRAM
-6-
ALIGNMENT INSTRUCTION
Your Remote Control
(R-43A07)
1. POWER
use this button to turn your TV on or off.
2. MUTE
Use to turn the TV's sound on and off.
MUTE POWER
3. CH
2 1 Use these buttons to change your TV's volume, to
activate selections in the menu system.
MENU
3
4. VOL
4 4 Use thesebuttons to change your TV's volume, to
5 VOL VOL activate selections in the meny system, or to change
3 audio and video settings.
CH
5. MENU
1 2 3
Use this button to turn the TV's menu system on and off.
9
4 5 6
6. DISPLAY
7 8 9
Use this button to display the channel numbeer and
status.
SLEEP 0 PREVIOUS 7. INPUT
10 11 Use this button to select the TV's signal source.
DISPLAY INPU T VIDE O
6 8
8. VIDEO
7 Use this button to display video adjustment.
9. 0-9
Use these buttons to change channels.
10. SLEEP
Use this button to program the TV to turn off after a
certain time.
11. PREVIOUS
Use this button to return to the previous channel you
were watching.
-7-
ALIGNMENT INSTRUCTION
1. SERVICE MODE ADJUSTMENTS
Follow the steps below whenever service adjustment is required. See Table- A and Table- B to determine if
service adjustments are required.
1) How to enter the service mode using the user remote control.