Text preview for : CH1 - Service Guide.pdf part of Samsung SV-637F 633F 630F 433F 430F 233F 230F SV-637X 636X 635X 633X 631X 6315X 6313X SV-530X 435X 433X 431X Service Manual Video Cassette Recorder - Tot 6 File - Part 1/3
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IMPORTANT SERVICE GUIDE
3 MODE SWITCH (PROGRAM SWITCH) ASSEMBLY POINT
1) When installing the ass'y full deck on the Main PCB, be sure to align the assembly point of mode switch.
ASSEMBLY POINT
Fig. 1
3 HOW TO EJECT THE CASSETTE TAPE (If the unit does not operate on condition that tape is inserted into housing ass'y)
1) Remove the Holder Worm OE and the gear worm ´. (See Fig. 2) 2) Turn the Gear Worm Wheel counterclockwise in the direction of arrow with screw driver. (See Fig. 2) 3) When Slider S, T are approached in the position of unloading, rotate holder Clutch counterclockwise after inserting screw driver in the hole of frame's bottom in order to wind the unwounded tape. (Refer to Fig. 3) (If you rotate Gear Worm Wheel continuously when tape is in state of unwinding, you may cause a tape contamination by grease and tape damage. Be sure to wind the unwounded tape in the state of set horizontally.) 4) Rotate Gear Worm Wheel counterclockwise using screw driver again up to the state of eject mode and then pick out the tape. (Refer to Fig. 2)
GEAR WORM WHEEL
SCREW DRIVER FRAME
´ GEAR WORM OE HOLDER WORM
Fig. 2
Fig. 3
1. 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 : 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 (See Fig. 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 (ANSI 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 the power outlet. With the unitÕs 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. 6. X-ray Limits : The picture tube is 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.
DEVICE UNDER TEST TEST ALL EXPOSED METER SURFACES 2-WIRE CORD ALSO TEST WITH PLUG REVERSED (USING AC ADAPTER PLUG AS REQUIRED) EARTH GROUND
LEAKAGE CURRENT TESTER
(READING SHOULD NOT BE ABOVE 0.5mA)
Fig. 1-1 AC Leakage Test 7. Antenna Cold Check : With the unitÕs 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. 8. High Voltage Limit : High voltage must be measured each time servicing is done on the B+, horizontal deflection or high voltage circuits. 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. 9. Some semiconductor (Òsolid stateÓ) devices are easily damaged by static electricity. Such components are called Electrostatically Sensitive Devices (ESDs); examples include integrated circuits and some field-effect transistors. The following techniques will reduce the occurrence of component damage caused by static electricity. 10. Immediately before handling any semiconductor components or assemblies, drain the electrostatic charge from your body by touching a known earth ground. Alternatively, wear a discharging Wrist-strap device. (Be sure to remove it prior to applying power--this is an electric shock precaution.)
Samsung Electronics
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Precautions
11. 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. 12. 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 manufacturerÕs warranty. 13. 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. 14. 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. 15. Never defeat any of the B+ voltage interlocks. Do not apply AC power to the unit (or any of its assemblies) unless all solid-state heat sinks are correctly installed. 16. Always connect a test instrumentÕs ground lead to the instrument chassis ground before connecting the positive lead; always remove the instrumentÕs ground lead last. 17. Observe the original lead dress, especially near the following areas : Antenna wiring, sharp edges, and especially the AC and high voltage power supplies. Always inspect for pinched, outof-place, or frayed wiring. Do not change the spacing between components and the printed circuit board. Check the AC power cord for damage. Make sure that leads and components do not touch thermally hot parts.
18. Picture Tube Implosion Warning : The picture tube in this receiver employs Òintegral implosionÓ protection. To ensure continued implosion protection, make sure that the replacement picture tube is the same as the original. 19. Do not remove, install or handle the picture tube without first putting on shatterproof goggles equipped with side shields. Never handle the picture tube by its neck. Some Òin-lineÓ picture tubes are equipped with a permanently attached deflection yoke; do not try to remove such Òpermanently attachedÓ yokes from the picture tube. 20. Product Safety Notice : Some electrical and mechanical parts have special safety-related characteristics which might not be obvious from visual inspection. These safety features and the protection they give might be lost if the replacement component differs from the original--even if the replacement is rated for higher voltage, wattage, etc. Components that are critical for safety are indicated in the circuit diagram by shading, ( or ). Use replacement components that have the same ratings, especially for flame resistance and dielectric strength specifications. A replacement part that does not have the same safety characteristics as the original might create shock, fire or other hazards.
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Samsung Electronics