Daewoo DSA-9310E, Service Manual

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1. PRODUCT SAFETY SERVICING GUIDELINES FOR RECEIVERS
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CAUTION : Do not attempt to modify this product in any way. Unauthorized modifications will not only
void the warranty, but may lead to your being liable for any resulting property damage or user injury.
Service work should be performed only after you are thoroughly familiar with all of the following safety
checks and servicing guide-lines. To do otherwise, increases the risk of potential hazards and injury to the
user.
SAFETY CHECKS
After the original service problem has been corrected, a check should be made of the following:
SUBJECT : FIRE & SHOCK HAZARD
1. Be sure that all components are positioned in such a way as to avoid possibility of adjacent component
shorts.
This is especially important on those chassis which are transported to and from the repair shop.
2. Never release a repair unless all protective devices such as insulators, barriers, covers, shields, strain
relief, and other hardware have been reinstalled per original design.
3. Soldering must be inspected to discover possible cold solder joints, frayed leads, damaged insulation
(including A.C. cord), solder splashes or sharp solder points. Be certain to remove all loose foreign
particials.
4. Check for physical evidence of damage or deterioration to parts and components, and replace if
necessary follow original layout, lead length and dress.
5. No leads or components should touch a receiving tube or a resistor rated at 1 watt or more. Lead
tension around protruding metal surfaces must be avoided.
6. All critical components such as fuses, flameproof resistors, capacitors, etc. must be replaced with exact
factory types. Do not use replacement components other than those specified or make
unrecommended circuit modifications.
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 knob, antenna terminals, handle and screws) to be sure the set is safe to
operate without danger of electrical shock. Do not use a line isolation transformer during this test. Use
an A.C. voltmeter, having 5000 ohms per volt or more sensitivity, in the following manner : connect a
1500 ohm 10 watt resistor, paralleled by a 15 mfd. 150V A.C. type capacitor between a known good
earth ground (9water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the
A.C. voltage across the combination of 1500 ohm resistor and 0.15 MFD capacitor. Reverse the A.C.
plug and repeat A.C. voltage measurements for each exposed metallic part. Voltage measured must not
exceed 0.75 volts R.M.S. This corresponds to 0.5 milliamp A.C. Any value exceeding this limit
constitutes a potential shock hazard and must be corrected immediately.