Barry777
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Jan 18, 2010, 6:32 AM
Post #4 of 4
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Re: [pukhog3] JVC SR-V10U Intermittent Static Issue
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I've made it a new habit to fully recap the power supply (electrolytics only) before proceeding any further with diagnosis, repair or ESPECIALLY adjustment of any kind. True, it may be a capstan servo problem - but that capstan servo circuit may be getting dirty enough power to malfunction. The last 4 VCR's I've worked on (all Beta) needed power supply recap jobs before they would perform solidly - and TWO of them appeared to be a capsan servo issue. Since some VCR circuits are extremely critical in terms of alignment, they also need very clean DC power to function correctly. Most GOOD VCR's have become old enough for the electrolytics to start getting leaky. I even had one in which there was NO capstan or drum rotation - power supply caps fixed it. Another thing I've learned is, before making any firm decisions on what kind of repairs to go after, to let the machine play continuously for a couple days. This breaks the machine back in, and in a few cases the machine will "fix itself", or break down an iffy problem altogether, thus making the problem easier to find. I definitely don't even think about touching any adjustments until after this break-in period. In many cases, the alignment is just fine and the problem is bad power supply caps. If you adjust it, then discover it's bad PS caps and replace them, you likely just screwed up the alignment when it was fine to begin with. No big deal on a VHS machine, but woe betide the Beta owner who did this - half a day to realign it! . . . Barry Fone - VCR Repair hobbyist and professional FAA Repair Station Avionics Bench Technician (top level). TEST EQUIPMENT: (4) Sencore VC93 VCR Analyzers, (11) Tentel gauges, Sencore VA48 and (2) VA62 Video Analyzers, Sigma Electronics TSG-375 NTSC/SMPTE Video Generator, several VCR Alignment Tapes, plus countless Oscilloscopes, Frequency Counters, Wow and Flutter Meters, Distortion Analyzers, Vectorscope, 136-channel Logic Analyzer, Signature Analyzer . . . . VIDEO GEAR: (6) JVC BR-S822U's, (3) JVC BR-7000 series, (3) JVC BR-S500U, (2) JVC BR-S800U, JVC GR-800U and (2) GR-860U Editing Controllers, Sony FXE-100 Video Switcher/Effects Generator, (5) Time Code Generator/Readers, (1) Sony SLO-1800 (Beta), (2) Alesis ADAT-XT, (1) Sony DXC-1200 TV Camera, Pioneer VP-1000 Laser Disc Player plus many consumer grade Beta and VHS VCR's. Passionate electronics enthusiast since 1973...most anything except computers. Check out my collection at www.barrys8trackrepair.com/MyVideoGear.html
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