#16
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Then they had a bunch of commercials for some what I thought looked like really cool toys when I was a kid and watched these old tapes, including commercials for the NES (the NES was still being produced in 1991 when the christmas specials tape from 1991 was recorded) and SNES (which was out a year by the time the 1993 Christmas specials tape was recorded). I'll have to get those tapes out and get some screen shots off of them for the commercials. |
#17
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Well Unfortunately my VCR's Power supply Died, I'm not sure what's wrong with it, because I thought maybe some of the caps had died in it, and I replaced what I thought were the bad caps and sure enough it is still blowing fuses, so I'm not sure what's going on with it.
Any ideas as to what might be wrong with this unit? |
#18
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Anyone?
I have a tape stuck in this VCR and can't get it out, its one of the original Star Wars Movies that was from 1995 where it was the last release of the original Star Wars Movies that used the original unedited theatrical Relase of the Films (where Jaba the Hut was actually a man in a Suit rather than the later CGI Giant Slug Like Character that they made him into in the 1997 Remaster, and the version where you actually saw who fired the first shot in the bar scene, which was obscured in the 1997 Remastered Version). I know on the Panasonic VCRs from the 1990s that had the modular Switch Mode Power Supply units, that usually what killed the power supply in those was one of the main filter caps in the secondary of the power supplies. Which is what I thought happened with this unit but wasn't the case because when I replaced those caps that I thought were what failed (they were bulged on the bottom and vented onto the circuit board which nearly obliterated some of the traces) the VCR is still blowing its fuses and because of that it won't power up at all, and when the fuse blows it blows so hard that the inside of the fuse turns pitch black and you can't see inside of it, which usually indicates a short of some sort but I'm not sure what would be shorted inside this VCR's Power Supply Unit, except maybe a capacitor, it isn't a bad power transformer because this VCR uses the famous Panasonic SMPS Mondule that Panasonic was known for using in all of their VCRs starting in mid 1980s and clear up until the early 2000s, on all of their VCRs. Any help in this matter would be appreciated. |
#19
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Diodes and transistors sometimes short when they are feeding excessive current into a shorted capacitor.
I'm not one to advise on troubleshooting that kind of issue as once something that new fails that bad I usually throw it out. If all you care about is the tape there are ways of recovering tapes from dead mechs. If the tape isn't threaded onto head drum simply locate the motor that actuates the eject mechanism and hook a 9V battery up to get it to spit the tape out (reverse polarity if it don't move the right direction), or if the eject mech is jammed unscrew stuff above the tape till you can lift the tape out by hand. If the tape is threaded before you can work the eject mech you need to find the threading motor and get it to spin to the unthread position (9V battery again is good for that) then find a way to spin the supply or take up reel on the tape to suck all the tape back into the cassette. Once all the tape is back into the cassette shell you can safely skip to the above paragraph on the eject mech.
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#20
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Somewhere on the power supply "box" you should find the Panasonic part number, should start with something like "VEJS" or similar. Shorted transistors, avalanche diodes and the caps were frequently bad together. Sometimes it was cheaper to order the whole unit from Panasonic rather than piece it back together. With the part number you may be able to search for one.
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Audiokarma |
#21
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Agree .Linear audio track from the stationary ACE head.EP speed sounds like AM radio with the wow and flutter like a cheap cassette recorder..SP mode was like FM radio on a cheap blank cassette.
It was a god send when the HiFi stereo VCRs came out .Thats when I bought a Panasonic HiFi Stereo portable VCR with tuner in 1985...Since it did not have a built in MTS decoder.I had the Rat Shack Realistic TV-100 MTS receiver hooked up on it.. vortalexfan.Thats Youtube gold with those old tapes.. With jammed tapes.I usually hand wind the drives with my fingers to get the tapes out.Do it slowly for the tape damage dont get worse. |
#22
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#23
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I think I may have figured out what failed on my VCR's Power supply, the Safety Cap (which in this VCR's Case was an X3 style safety cap rated at 130 pF and 2.7 MΩ) failed.
I would guess that a failed safety cap would kill a VCR power supply? |
#24
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If somehow the safety cap shorted, then that would definitely pop a fuse upstream. |
#25
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When I measured across it with my multimeter with resistance mode it measured O. L. right away. |
Audiokarma |
#26
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Then it's not shorted. Have you checked other components in the power supply? I've heard of transistors shorting when a switch mode power supply fails.
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#27
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The only other component that measured questionable was the bridge rectifier (D1). |
#28
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What do you mean by measured questionable?
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#29
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Well the side of the bridge rectifier that has the (+) and (-) marks on it measures .003V both directions and beeps and the (~) side measures 1.2V both ways and doesn't beep.
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#30
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For the DC side (+ and -) you should see close to 1.0v but only in one direction. |
Audiokarma |
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