Hitachi DVP 315 U Service Manual

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Precautions 1-1 1. Precautions 1-1 Safety Precautions 1) Before returning an instrument to the customer, always make a safety check of the entire instrument, including, but not limited to, the following items: (1) Be sure that no built-in protective devices are defective or have been defeated during servicing. (1)Protective shields are provided to protect both the technician and the customer. Correctly replace all missing protective shields, including any remove for servicing convenience. (2)When reinstalling the chassis and/or other as- sembly in the cabinet, be sure to put back in place all protective devices, including, but not limited to, nonmetallic control knobs, insulating fish papers, adjustment and compartment covers/shields, and isolation resistor/capacitor networks. Do not operate this instrument or permit it to be operated without all protective devices correctly installed and functioning. (2) B e sure that there are no cabinet openings through which adults or children might be able to insert their fingers and contact a hazardous voltage. Such openings include, but are not limited to, excessively wide cabinet ventilation slots, and an improperly fitted and/or incorrectly secured cabinet back cover. (3) Leakage Current Hot Check-With the instrument completely reassembled, plug the AC line cord directly into a 120V AC outlet. (Do not use a 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) 1270 (40.7). With the instrument's AC switch first in the ON position and then in the OFF position, measure from a known earth ground (metal water pipe, conduit, etc.) to all exposed metal parts of the instrument (antennas, handle brackets, metal cabinets, screwheads, metallic overlays, control shafts, etc.), especially any exposed metal parts that offer an electrical return path to the chassis. Any current measured must not exceed 0.5mA. Reverse the instrument power cord plug in the outlet and repeat the test. See Fig. 1-1.Any measurements not within the limits specified herein indicate a potential shock hazard that must be eliminated before returning the instrument to the customer. Fig. 1-1 AC Leakage Test (4) Insulation Resistance Test Cold Check-(1) Unplug the power supply cord and connect a jumper wire between the two prongs of the plug. (2) Turn on the power switch of the instrument. (3) Measure the resistance with an ohmmeter between the jumpered AC plug and all exposed metallic cabinet parts on the instrument, such as screwheads, antenna, control shafts, handle brackets, etc. When an exposed metallic part has a return path to the chassis, the reading should be between 1 and 5.2 megohm. When there is no return path to the chassis, the reading must be infinite. If the reading is not within the limits specified, there is the possibility of a shock hazard, and the instrument must be re-pared and rechecked before it is returned to the customer. See Fig. 1-2. Fig. 1-2 Insulation Resistance Test DEVICE UNDER TEST(READING SHOULD NOT BE ABOVE 0.5mA) LEAKAGE CURRENT TESTER EARTH GROUND TEST ALL EXPOSED METER SURFACES ALSO TEST WITH PLUG REVERSED (USING AC ADAPTER PLUG AS REQUIRED) 2-WIRE CORD Antenna Terminal Exposed Melal Part ohm ohmmeter

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Precautions 1-2 2) Read and comply with all caution and safety re- lated notes non or inside the cabinet, or on the chassis. 3) Design Alteration Warning-Do not alter of add to the mechanical or electrical design of this instrument. Design alterations and additions, including but not limited to, circuit modifications and the addition of items such as auxiliary audio output connections, might alter the safety characteristics of this instrument and create a hazard to the user. Any design alterations or additions will make you, the service, responsible for personal injury or property damage resulting therefrom. 4) Observe original lead dress. Take extra care to assure correct lead dress in the following areas: (1) near sharp edges, (2) near thermally hot parts (be sure that leads and components do not touch thermally hot parts), (3) the AC supply, (4) high voltage, and (5) antenna wiring. Always inspect in all areas for pinched, out-of-place, or frayed wiring, Do not change spacing between a component and the printed-circuit board. Check the AC power cord for damage.5) Components, parts, and/or wiring that appear to have overheated or that are otherwise damaged should be replaced with components, parts and/ or wiring that meet original specifications. Additionally, determine the cause of overheating and/or damage and, if necessary, take corrective action to remove any potential safety hazard. 6) Product Safety Notice-Some electrical and mechanical parts have special safety-related characteristics which are often not evident from visual inspection, nor can the protection they give necessarily be obtained by replacing them with components rated for higher voltage, wattage, etc. Parts that have special safety characteristics are identified by shading, an ( )or a ( )on schematics and parts lists. Use of a substitute replacement that does not have the same safety characteristics as the recommended replacement part might created shock, fire and/or other hazards. Product safety is under review continuously and new instructions are issued whenever appropriate.

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5-10 Disassembly and Reaasembly 5-4-3 Housing Ass'y Removal 1) Remove Belt Œ. 2) Push the Hook ´in the direction arrow "A" and lift up Pulley Gear ˇ. 3) Push the Slider Housing ˆin the direction arrow "B" and lift up the Gear Tray ¨. 4) Lift up the Slider Housing ˆ. 5) Remove the soldering Ø of 2 points (Red, Black). 6) Remove 2 Screws -�� and lift down the Motor Load Assy . 7) Push the 3 Hooks bottom side in the direction arrow "C" and lift up the Housing PCB ˝. 8) Push the Hooks �-and remove Deck PCB . Fig. 5-10 Housing Ass'y Removal Œ BELT ˇ PULLEY GEAR ¨ GEAR TRAY MOTOR LOAD ASSY 3 HOOKS ˝ HOUSING PCB  DECK PCB �- HOOK Ø SOLDERING -�� 2 SCREWS ˆ SLIDER HOUSING ´ HOOK "A" "B" "C" "C" "C"