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Scott Hutchins writes:

>I few weeks ago I tried to watch the former rental tape I bought of _The
>Quiet Earth_ and found that it turns blue and starts to rewind 15 minutes
>from the end of the film.

The reason for this is that many consumer VCRs have inbuilt safety devices
in them which detect tape defects which, if the tape were allowed to
continue playing, might cause irreparable damage to the machine.  While in
some instances they can be over-paranoid, I would hazard a guess that in
your case the detector detected a problem and duly stopped the tape from
playing any further.  Examples of such defects include creases or other
base deformations, edge shearing, badly shedding oxide, foreign bodies
stuck to the tape &c. &c.

>I tried to open the casette up, but, while most of the screws were
>Phillips head, the one in the center has a Y-shaped hole in the head, and
>nothing I had would work in it without damaging the screw.

The bottom line is that, basically, unless you're prepared to risk
sodomising both the tape and the VCR, opening the cassette up is a BAD
idea.  Given that VHS VTRs are now practically given away nowadays you
might be prepared to risk the loss of one if the content of your tape is
valuable enough, but it's worth flagging up that this is what's at stake.

In the case of an internal cassette defect (e.g. an idler shearing in a
cheap and nasty VHS cassette), you can sometimes rescue the content by
transplanting the tape into a fresh cassette.  We recently had a collection
of amateur footage acquired on VHS cassettes which their owner had
converted to S-VHS by the simple expedient of drilling a hole in the
requisite location in the cassette shell.  Thanks to the swarf from the
drilling getting trapped inside the original cassettes I ended up having to
transplant the tapes into proper S-VHS shells, but this was done in a clean
air environment (I used a fume box in a chemistry lab for the
purpose).  And even though I've done an obscenely expensive four-day course
in magnetic tape conservation techniques my heart is always in my mouth on
the mercifully rare occasions I have to dissect cassettes.

So, without wanting to sound like a condescending 'leave this to the
professionals' type, I would just flag up that playing about with the
innards of videocassettes is almost always never as straightforward as it
might seem.  Unless you're feeling very brave, my advice would be to buy
the flickery PAL version and live with it.

That having been said, if you do decide to have a go, the technique I'd
suggest is as follows.

Buy two new blank VHS cassettes of exactly the same brand (this is important).
If you can rewind the cassette containing the tape to be transplanted, so
that the tape is all on one spool, do so.
If possible, work in a clean air environment.  If not, you want a very
clean work surface, a non-dusty atmosphere and certainly no smoking in the
room.
Blank VHS cassette #1 will receive the transplanted tape.
Blank VHS cassette #2 will act as a reference guide when threading the tape
into cassette #1.
Lay all three cassettes, bottom side up, in a row.
Remove the five retaining screws which hold the two sides of the cassette
shells together from cassettes #1 and #2.
Remove the spring mechanism holding the tape guard flap at the front from
cassette #1.  This may involve trial, error and/or brute force.  It doesn't
matter if you accidently destroy any parts in this process, though try not
to. Note the way the tape guard flap mechanism reassembles while doing
this: make sketches or take a digital photo or two if this would help.
Remove the two tape spools from cassette #1 and bin them.
Remove the spring mechanism holding the tape guard flap at the front from
cassette #2.  This time you want to be careful NOT to damage or destroy
anything, though if you accidently did so previously you can replace parts
of #1 from #2.
Leave the spools in place and the tape threaded in #2 for visual reference.
Remove the five retaining screws which hold the two sides of the cassette
shells together from the cassette containing the recording you want to save
(hereafter 'the original').  Don't worry about being brutal with that weird
screw just as long as you don't damage or destroy the tape itself.
Lift away the two spools and threaded tape from the original and place them
on the bench next to you.
Remove and discard the cassette which contained the original.
Looking at the threaded tape still in place in cassette #2, place the two
spools containing the original tape into #1 and thread the tape so that the
two match.  This is why it's important that cassettes #1and #2 should be of
exactly the same brand - there are differences in the threading path.
Reassemble the tape guard flap mechanism on cassette #1.  If taking it
apart was messy, you may have to cannibalise parts from #2.
Put the cassette of #1 back together, now containing the original
tape.  Replace the five screws.
If you've done it right, it should play!

I get the impression that this is a very humanities-centric list which, the
readers of which don't appreciate technical detail as a general rule; so
therefore I'll refrain from writing lots of stuff about the tolerances of
helical scan heads and tape transports &c. &c...

Oh and, by the way, those of us in PAL-land find NTSC tapes and DVDs
flickery too!  AND you get 100 fewer lines of horizontal resolution.  It's
not for nothing that PAL is known as 'Picture Always Lovely' compared
to  NTSC's 'never twice the same colour'!

Leo

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