DAEWOO ELECTRONICS DTQ-14U1FS, Service Manual

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PRODUCT SAFETY SERVICING GUIDE PRODUCT SAFETY SERVICING GUIDEL LINES FOR COLOR INES FOR COLOR TELEVISION RECEIVERS TELEVISION RECEIVERS
CAU CAUTION : Do not att TION : Do not attemp empt t t to mo o modif dify thi y this product i s product in any way. Unau n any way. Unau--
thorized modifications will not only void the warranty, but may lead to thorized modifications will not only void the warranty, but may lead to
your being liable for any resulting property damage or user injury.
your being liable for any resulting property damage or user injury.
Service work should be performed only after you are thoroughly
Service work should be performed only after you are thoroughly
famili
familiar w ar witith a h all of t ll of the he foll following owing safety safety check checks an s and se d servici rvicing g ng guide- uide-
lilines. T nes. To do otherw o do otherwise, i ise, increase ncreases the ri s the risk of potential sk of potential hazard hazards and s and
injury to the user. injury to the user.
SAFETY CHECKS SAFETY CHECKS
A Aft fte er r th the e o orrig igin ina al l s se errv vic ice e p prro ob ble lem m h ha as s b be ee en n c co orrrre ec cte ted d, , a a c ch he ec ck k s sh ho ou uld ld
be m be made of the fol ade of the following: lowing:
SUBJECT : FIRE & SHOCK HAZARD SUBJECT : FIRE & SHOCK HAZARD
1. Be sure that all 1. Be sure that all compo components are posit nents are positioned in such a way ioned in such a way as to as to
avoid possibility of adjacent component shorts. This is especially avoid possibility of adjacent component shorts. This is especially
important on t
important on those chassis wh hose chassis which are tr ich are transported to and from the ansported to and from the
repair repair shop shop..
2. Never release a repair unless all protective devices such as insula- 2. Never release a repair unless all protective devices such as insula-
tors, barriers, covers, shields, strain reliefs, and other hardware tors, barriers, covers, shields, strain reliefs, and other hardware
have been reinstalled per original design.
have been reinstalled per original design.
3. Soldering must be inspected to discover possible cold solder joints, 3. Soldering must be inspected to discover possible cold solder joints,
frayed leads, damaged insulation (including A.C. cord), solder frayed leads, damaged insulation (including A.C. cord), solder
splashes o
splashes or sharp solder points. r sharp solder points. Be certain to remove all l Be certain to remove all loose for- oose for-
eign particals. eign particals.
4. Check for physical evidence of damage or deterioration to parts 4. Check for physical evidence of damage or deterioration to parts
and components, and replace if necessary follow original layout, and components, and replace if necessary follow original layout,
lead length
lead length and and dress. dress.
5. No leads or components should touch a receiving tube or a resistor 5. No leads or components should touch a receiving tube or a resistor
rated at 1 rated at 1 wa watt tt or more. Lead tension arou or more. Lead tension around protruding me nd protruding metal tal sur- sur-
faces must be avoided. faces must be avoided.
6. All critical components such as fuses, flameproof resistors, capaci- 6. All critical components such as fuses, flameproof resistors, capaci-
tors, etc. must be replaced with exact factory types. Do not use tors, etc. must be replaced with exact factory types. Do not use
replacement compon
replacement components other t ents other than those specifi han those specified or m ed or make ake
unreco unrecomm mmende ended d circuit circuit mo modifi difications. cations.
7. After re-assembly of the set always perform an A.C. leakage test 7. After re-assembly of the set always perform an A.C. leakage test
on all exposed metallic parts of the cabinet, (the channel selector on all exposed metallic parts of the cabinet, (the channel selector
knob, antenna terminals, handle and screws) to be sure the set is
knob, antenna terminals, handle and screws) to be sure the set is
safe to operate without danger of electrical shock. Do not use a
safe to operate without danger of electrical shock. Do not use a
line isolation transformer during this test. Use an A.C. voltmeter,
line isolation transformer during this test. Use an A.C. voltmeter,
having 5000 ohms per volt or more sensitivity, in the following
having 5000 ohms per volt or more sensitivity, in the following
man
manner : connect a 1500 ohm ner : connect a 1500 ohm 10 wa 10 watt tt resist resistor, paral or, parallel leled by a ed by a 15 15
mfd. 150V A.C. type capacit mfd. 150V A.C. type capacitor between a know or between a known good earth n good earth
ground (9water pipe, conduit, etc.) and the exposed metallic parts, ground (9water pipe, conduit, etc.) and the exposed metallic parts,
one at a time. Measu
one at a time. Measure the A.C. volt re the A.C. voltage across the com age across the combinat bination of ion of
1500 ohm 1500 ohm resist resistor and 0.15 MF or and 0.15 MFD capacitor. D capacitor. Reverse the A.C. plug Reverse the A.C. plug
and repeat A.C. voltage measurements for each exposed metallic and repeat A.C. voltage measurements for each exposed metallic
part. Voltage measured must not exceed 0.75 volts R.M.S. This
part. Voltage measured must not exceed 0.75 volts R.M.S. This
correspo
corresponds to 0.5 mil nds to 0.5 milliliam amp A.C. Any value excee p A.C. Any value exceeding thi ding this li s limit mit
consti constitut tutes a p es a potent otential ial shock hazard shock hazard and m and must be corrected imme- ust be corrected imme-
diately. diately.
GRAPHIC SYM GRAPHIC SYMBOLS BOLS ::
The lightning flash with arrowhead symbol, The lightning flash with arrowhead symbol,
within an equilateral triangle, is intended to alert
within an equilateral triangle, is intended to alert
the service personnel to t
the service personnel to the presen he presence of uninsu- ce of uninsu-
lated “ lated “dang dangerous vo erous voltltage” that ma age” that may be of suffi y be of suffi--
cienty magnitude to constitute a risk of electric cienty magnitude to constitute a risk of electric
shock.
shock.
The exclamation point within an equilateral tri- The exclamation point within an equilateral tri-
angle is intended to alert the service personnel angle is intended to alert the service personnel
to the presence of important safety information
to the presence of important safety information
in service li
in service literature. terature.
Fuse symbol is printed on pcb adjacent to the Fuse symbol is printed on pcb adjacent to the
fus
fuse, wi e, with “ th “RISK OF F RISK OF FIRE REPLAC IRE REPLACE FUS E FUSE AS E AS
MA MARKE RKED”. The symbol is expl D”. The symbol is explained i ained in the ser- n the ser-
vice manual with the following wording or equiv- vice manual with the following wording or equiv-
alent.
alent.
““ CAUT CAUTIO ION : N : FOR CON FOR CONTINUED PROTECTION AGAINST FI TINUED PROTECTION AGAINST FIRE RE
HAZARD, REPLACE ON HAZARD, REPLACE ONLY W LY WIITH SAME TH SAME TYPE (4A, 1 TYPE (4A, 125V) 25V)” and ” and
““
ATTENTI ATTENTION ON
: AFI : AFIN D’ASSU UNE PROTECTION PERM N D’ASSU UNE PROTECTION PERMANENTE ANENTE
CONTRE CONTRE LES RISQUES D’I LES RISQUES D’INCENDIE, REMPLACER UNIQUE- NCENDIE, REMPLACER UNIQUE-
MENT PAR MENT PAR UN FUSIBLE DE MEME TYP UN FUSIBLE DE MEME TYPE ET DE ”4A, E ET DE ”4A, 125V” 125V”..
SUBJECT : X-RADIATION SUBJECT : X-RADIATION
1. Be sure proced 1. Be sure procedures and instructi ures and instructions to all ons to all service person service personnel cover nel cover
the subject of X-rays in current T.V. receivers is the picture tube. the subject of X-rays in current T.V. receivers is the picture tube.
However, this tube does not emit X-rays when the high voltage is
However, this tube does not emit X-rays when the high voltage is
at the factory specified level. The proper value is given in the appli-
at the factory specified level. The proper value is given in the appli-
cable schematic. Operation at higher voltages may cause a failure
cable schematic. Operation at higher voltages may cause a failure
of the pict
of the picture tube or high voltage supp ure tube or high voltage supply and, under certain cir- ly and, under certain cir-
cum cumstances, may prod stances, may produce radiation i uce radiation in excess of desirable l n excess of desirable levels. evels.
2. Only factory specified C.R.T. anode connectors must be used. 2. Only factory specified C.R.T. anode connectors must be used.
Degaussing shields also serve as X-ray shield in color sets. Degaussing shields also serve as X-ray shield in color sets.
A Alw lwa ay ys s rre e--in ins sta tall ll th the em m..
3. It is essential that the serviceman has available an accurate and 3. It is essential that the serviceman has available an accurate and
reliable high voltage meter. The calibration of the meter should be reliable high voltage meter. The calibration of the meter should be
checked perio - dically against a reference standard. Such as the
checked perio - dically against a reference standard. Such as the
one available at your distributor.
one available at your distributor.
4. When the high voltage circuitry is operating properly there is no 4. When the high voltage circuitry is operating properly there is no
possibility of an X-radiation problem. Every time a color chassis is possibility of an X-radiation problem. Every time a color chassis is
serviced, the brightness should be run up and down while monitor-
serviced, the brightness should be run up and down while monitor-
ing the high voltage with a meter to be certain that the high voltage
ing the high voltage with a meter to be certain that the high voltage
does
does not exce not exceed the s ed the specifi pecified va ed value and lue and that it that it is regulati is regulating ng cor- cor-
rectly. We suggest that you and your service organization review rectly. We suggest that you and your service organization review
test procedures so that voltage regulation is always checked as a
test procedures so that voltage regulation is always checked as a
standard servicing procedure. And that the high voltage reading be
standard servicing procedure. And that the high voltage reading be
recorded on e
recorded on each customer’s invoi ach customer’s invoice. ce.
5. When 5. When troubl troubleshooting and ma eshooting and making test king test mea measurements in a receiver surements in a receiver
with a problem of excessive high voltage, avoid being unnecessarily with a problem of excessive high voltage, avoid being unnecessarily
close to the picture tub eand the high voltage compartment.
close to the picture tub eand the high voltage compartment.
Do not operate the chassis longer than is necessary to locate the Do not operate the chassis longer than is necessary to locate the
cause of excessive voltage. cause of excessive voltage.
6. Refer t 6. Refer to HV o HV, B+and Shutdow , B+and Shutdown adjustment procedures descri n adjustment procedures described in bed in
the appropriate schematic and diagrams(where used). the appropriate schematic and diagrams(where used).
10WATT 10WATT
Good earth ground, Good earth ground,
such as the water
such as the water
pipe, conduit, etc.
pipe, conduit, etc.
1500 OHM 1500 OHM
A.C A.C. V . VOLT OLTME METER TER
Place this probe Place this probe
on each exposed on each exposed
metal part. metal part.
0.15 uF 0.15 uF