Jvc PCV 77 Service Manual
This is the 36 pages manual for Jvc PCV 77 Service Manual.
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Extracted text from Jvc PCV 77 Service Manual (Ocr-read)
Page 1
tJ PC-V77 A/B/E/G/UN f-'. et f-'. N (j) P- ot< ;J M M Ul M ::0 < H () i t-< Ul H Z hj o Safety Precautions 1. The design of this product contains special hardware. Many circuits and compo nents specially for safety purposes. For continued protection, no changes should be made to the original design unless authorized in writing by the manufacturer. Replacement parts must be identical to those used in the original circuits. Service should be per formed by qualified personnel only . 2. Alterations of the design or circuitry of the product should not be made . Any design alterations or additions will void the manufacturer's warranty and will further relieve the manufacturer of responsibi lity for personal injury or pro perty damage resulting therefrom. 3. Many electrical and mechanical parts in the product have special safety - related characteristics. These characteri stics are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage , wattage, etc. Replacement parts which have these special safety characteristics are identified in the parts list of Service manual. El ectrical components hav ing such features are identified by (Lt) on the schematics and parts list in Service manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement part shown in the parts list in Service manual may create shock, fire, or other hazards. 4. The leads in the products are routed and dressed with ties , clamps, tubings, barriers and/ or the like to be separated from live parts, high temperature part, mov ing parts and / or sharp edges for the prevention of elec tric shock and fire hazard . When service is required , the original lead routing and dress should be observed, and they should be confirm ed to be returned to normal , after re -assembling. 5. Leakage current check (Safety for electrical shock hazard) A fter re -assembling the product , always perform an isola tion check on the exposed metal parts of the Products (antenna terminals , knobs , metal cabinet, screw heads, earphone jack , control shafts, etc.) to be sure the pro duct is safe to operate without danger of electrical shock. 2 (No. 1740) Do not use a line isolation transformer du ring this check. - Plug the AC line cord directly into the AC outlet. Us in g a "Leakage Current Tester", measure the leakage current from each exposed metal part of the cabinet, particularly any exposed metal part having a return path to the chassis, to a known good earth ground (water pipe, etc.). Any leakage current must not ex ceed 0.5 mA AC (r.m.s.). - Alternate check method. Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having 1,000 ohms per volt or more sensitivity in the following manner . Connect a 1500 {l 10 W resistor paralleled by a 0.15 /LF AC - type capacitor between an exposed metal part and a known good earth ground (water pipe , etc.) Measure the AC voltage across the resistor with the AC voltmeter. Move the resistor connection to each exposed metal part , particularly any exposed metal part having a return path to the chassis, and measure the AC voltage across the resistor. Now, reverse the plug in the AC outlet and repeat each measurement. Any voltage measured must not exceed 0.75 V AC (r.m.s.) . This corresponds to 0.5 mA AC (r.m .s.). AC VOLTMETER (HAVING 1000 ON , OR MORE SENSITIVITY I 0.1 5 /LF AC -TYPE GOOD EARTH GROUND PLACE THIS PROBE ON EACH EXPOSED METAL PART
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t:J C'-cO C'-et C'-N (D P- t) '< j hj ::0 M M (j) M ::0 < H n M ~ S; t-< (j) H Z hj 0 ~ Location of Main Parts Main Board -- Ass 'V Speaker Term inal Switch SEA Cover Power Transformer Fig . 2-1 AMP /SEA Board Ass'V CD Jack Ass'v INo. 1740) 3