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Default Having playback issues when recording for awhile, VCR brand JVC hr-S3900


"Mark Zacharias" wrote in message
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"N_Cook" wrote in message
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truepurple wrote in message
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I got this vcr some years ago, it was one of the most expensive in the
store. I am a bit of a environmentalist too, so I would much rather
fix then replace. Add to that the fact that even finding a VCR that
records is in itself difficult now adays...

Anyway here is the problem.

If I have been recording for awhile(hour or so?), the VCR starts
recording a strange kind of noise onto the tape. The picture shifts or
jitters at spots like tiny hooks are pulling at the image misaligning
it in spots horizontally. This happens only for a moment but at
regular intervals every 4 seconds or so?(not sure of exact time) the
sound is slightly distorted too at the exact same spot as the picture.
As playback goes on, this effect gets stronger. It is not the tape.

When it is recording, at the point where it starts recording the noise
onto the tape, I can hear a kind of squeaking rubbing sound that is
difficult to explain at regular intervals equal to the noise/
distortion on the tape which just like the recording itself gets
louder as it continues recording.

If I dont use the vcr for some time this effect goes away. But more
then say a hour or two of nonuse is required before I can get a half
hour/hour of record time relatively noise free.

Talking to repair shops, I get the old "Probably not worth the money
to repair, but if you come in, we will do what ever, then charge you
(lots of money)" chestnut. General opinion points to it possibly being
the motor, and that buying a new motor would be prohibitively
expensive.(for the value of the item in question)

http://www.repairfaq.org states that when a motor dies, it usually
dies spectacularly. Does this apply to VCR motors too?

If it is the motor, Does the motor have to be exactly for that model?
Or could a similar motor be made to work? Could I just open it up,
find the motor,(not entirely sure what to look for) and clobber it
with a bit of bike chain lub?

Another issue is that the VCR does not accept tapes feed into it well
all the time. The solution usually to push it in lightly for a short
bit of the distance.Otherwise the tape gets stuck at a spot three
quarters back or so, as it struggles to pull it in for a time till it
gives up and spits it back out. Sometimes it doesn't spit it back out
all the way though, leaving me to actually have to tilt the vcr
foreward to get the tap to come out via gravity (otherwise I can't
push it in or eject it) The pushing it in a bit method works fine for
now (if I remember) but I worry that it might get worse eventually.

Is the motor that is responsible for drawing in the tape different
then the one responsible for playing and recording on tapes?



Change the pinchwheel , or as a confirmation before getting one, try
turning
the pinchwheel upside down, if it is possible


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/





I'd be looking at power supply caps.

Mark Z.


Also, if there is a regular squeak, check that the guide rollers are free to
rotate, and that the back-tension band is not worn out. The fact that you
have this squeak that corresponds to the effect on the screen, is probably
the key to the problem. However, that said, sometimes, symptoms such as this
are caused by tape friction as a result of wear on the lower head drum. This
is especially the case, on machines where the tape remains wrapped during
wind / rewind operations. If it is that, then there's not a lot you are
going to do about it. The cost of a lower head drum assembly, if you could
even still get one, is likely to be prohibitive. Occasionally, if you've got
nothing to lose, a degree of recovery can be achieved, by using metal polish
to shine up the dull worn area on the lower drum. Note that this is the
*fixed* duralumin part of the drum, *not* the chrome rotating part

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