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 yourwithin 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 familiarlated dangerous voltage that may be of suffi-
with all of the following safety checks and servicing guide-lines. To docienty magnitude to constitute a risk of electric
otherwise, increases the risk of potential hazards and injury to the user.shock.
SAFETY CHECKSThe 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 beto the presence of important safety information
made of the following:in service literature.
SUBJECT : FIRE & SHOCK HAZARDFuse 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 avoidMARKED . The symbol is explained in the ser-
possibility of adjacent component shorts. This is especially important onvice 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 beenCAUTION : 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 splashesCONTRE 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 lengthSUBJECT : X-RADIATION
and dress.
5. No leads or components should touch a receiving tube or a resistor1. Be sure procedures and instructions to all service personnel cover
rated at 1 watt or more. Lead tension around protruding metal sur-facesthe 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 replacementcable schematic. Operation at higher voltages may cause a failure
components other than those specified or make unrecommended circuitof 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 all2. 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 tore-install them.
operate without danger of electrical shock. Do not use a line isolation3. It is essential that the serviceman has available an accurate and
transformer during this test. Use an A.C. voltmeter, having 5000 ohmsreliable high voltage meter. The calibration of the meter should be
per volt or more sensitivity, in the following manner : connect a 1500checked perio - dically against a reference standard. Such as the
ohm 10 watt resistor, paralleled by a 15 mfd. 150V A.C. type capacitorone available at your distributor.
between a known good earth ground (9water pipe, conduit, etc.) and4. When the high voltage circuitry is operating properly there is no
the exposed metallic parts, one at a time. Measure the A.C. voltagepossibility 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 eaching the high voltage with a meter to be certain that the high voltage
exposed metallic part. Voltage measured must not exceed 0.75 voltsdoes 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 thisrectly. 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. VOLTMETERoperate 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 GROUNDPLACE THIS PROBE
1500 OHM
SUCH AS THE WATERON EACH EXPOSED
PIPE, CONDUIT, ETC.
10WATTMETAL PART
-3- |
ACEC
DAEWOO
