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Precautions 2. Reference Information 3. Specifications 4. Alignment and Adjustments 5. Troubleshooting 6. Exploded Views and Parts List 7. Electrical Parts List 8. Block Diagrams 9. Wiring Diagram 10. Schematic Diagrams 1. Precautions 1-1 Safety Precautions 1. Be sure that all of the built-in protective devices are replaced. Restore any missing protective shields. 2. When reinstalling the chassis and its assemblies, be sure to restore all protective devices, including: nonmetallic control knobs and compartment covers. 3. Make sure that there are no cabinet openings through which people—particularly children—might insert fingers and contact dangerous voltages. Such openings include the spacing between the picture tube and the cabinet mask, excessively wide cabinet ventilation slots, and improperly fitted back covers. If the measured resistance is less than 1.0 megohm or greater than 5.2 megohms, an abnormality exists that must be corrected before the unit is returned to the customer. 4. Leakage Current Hot Check (Figure 1-1): Warning: Do not use an isolation transformer during this test. Use a leakage- current tester or a metering system that complies with American National Standards Institute (ANIS C101.1, Leakage Current for Appliances), and Underwriters Laboratories (UL Publication UL1410, 59.7). 5. With the unit completely reassembled, plug the AC line cord directly into the power outlet. With the unit’s AC switch first in the ON position and then OFF, measure the current between a known earth ground (metal water pipe, conduit, etc.) and all exposed metal parts, including: antennas, handle brackets, metal cabinets, screwheads and control shafts. The current measured should not exceed 0.5 milliamp. Reverse the power- plug prongs in the AC outlet and repeat the test. Fig. 1-1 AC Leakage Test 6. Antenna Cold Check: With the unit’s AC plug disconnected from the AC source, connect an electrical jumper across the two AC prongs. Connect one lead of the ohmmeter to an AC prong. Connect the other lead to the coaxial connector. 7. X-ray Limits: The picture tube is especially designed to prohibit X-ray emissions. To ensure continued X-ray protection, replace the picture tube only with one that is the same type as the original. Carefully reinstall the picture tube shields and mounting hardware; these also provide X-ray protection. 8. High Voltage Limits: High voltage must be measured each time servicing is done on the B+, horizontal deflection or high voltage circuits. Correct operation of the X-ray protection circuits must be reconfirmed whenever they are serviced. (X-ray protection circuits also may be called “horizontal disable” or “hold-down”.) Heed the high voltage limits. These include the X–ray Protection Specifications Label, and the Product Safety and X-ray Warning Note on the service data schematic. Precautions Samsung Electronics 1-1 LEAKAGE CURRENT TESTER DEVICE UNDER TEST TEST ALL EXPOSED METAL SURFACES 2-WIRE CORD ALSO TEST WITH PLUG REVERSED (USING AC ADAPTER PLUG AS REQUIRED) EARTH GROUND (READING SHOULD NOT BE ABOVE 0.5mA) Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards such as electrical shock and X-rays. LEAKAGE CURRENT TESTER DEVICE UNDER TEST TEST ALL EXPOSED METAL SURFACES 2-WIRE CORD ALSO TEST WITH PLUG REVERSED (USING AC ADAPTER PLUG AS REQUIRED) EARTH GROUND (READING SHOULD NOT BE ABOVE 0.5mA) Follow these safety, servicing and ESD precautions to prevent damage and protect against potential hazards such as electrical shock and X-rays. 1-1 Safety Precautions (Continued) 9. High voltage is maintained within specified limits by close-tolerance, safety-related components and adjustments. If the high voltage exceeds the specified limits, check each of the special components. 10. Design Alteration Warning: Never alter or add to the mechanical or electrical design of this unit. Example: Do not add auxiliary audio or video connectors. Such alterations might create a safety hazard. Also, any design changes or additions will void the manufacturer’s warranty. 11. Hot Chassis Warning: Some TV receiver chassis are electrically connected directly to one conductor of the AC power cord. If an isolation transformer is not used, these units may be safely serviced only if the AC power plug is inserted so that the chassis is connected to the ground side of the AC source. To confirm that the AC power plug is inserted correctly, do the following: Using an AC voltmeter, measure the voltage between the chassis and a known earth ground. If the reading is greater than 1.0V, remove the AC power plug, reverse its polarity and reinsert. Re-measure the voltage between the chassis and ground. 12. Some TV chassis are designed to operate with 85 volts AC between chassis and ground, regardless of the AC plug polarity. These units can be safely serviced only if an isolation transformer inserted between the receiver and the power source. 13. Some TV chassis have a seco...

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