Notes on the Troubleshooting and Repair of Video Cassette Recorders


  6.5) Polishing your tape path

(From: Gillraker (eternity@mcp.cybertron.com)).

I pride myself on the cleanings I do with all repairs, I like to keep my shop
up to command performance and a cut above the rest I usually even clean up the
chassis and deck of most equipment and relubricate and all the trim.

I have seen my share of broken heads come in from people after they use a
Q-tip...or a store bought cleaning tape...

I use a few different size hemostats with a folded up lint free cloth.  When
folded, it really buffs the cylinder units and leaves a nice shine on the tape
guide rollers, and audio and erase heads too.  I have cleaned a head with
chamois swabs and then gone over them with my own cloth and was horrified to
see the residue that was left from ordinary swabs, when it was all collected
on the cloth.  It doesn't snag the video or stereo hi-fi heads either - I
have cleaned a few thousand this way and never snagged any .

I use generation 2000 disk cleaner for heads and acetone to degrease the posts
and capstan - just a dip - not too much.

(Editor's note: take care with strong solvents like acetone - both to protect
your health and avoid damage to plastic parts. --- sam)

  6.6) Tom's comments on approaches to cleaning

(From: Thomas L DeTogne (tdetogne@home.com)).

Pardon me while I trip over my long gray beard :-).

In the old days, we used to clean the platters in a disk drive using what were
essentially tongue depressors wrapped with a Texwipe (Lint-free paper).  We
would first use 99% pure isopropyl alcohol and follow it with freon.  (AAAAAh!
the Ozone layer!) We would then manually run the heads out over the platters
(while they were spinning) and listen for 'ticks'.  If we heard any, we'd
repeat the process.  For those who smoked in the computer room, the residue
could build up rather thick and evenly.  Getting the whole mess off was a
chore.  If such was the case, I actually would use Soap and water, followed by
water, then the alcohol and finally the freon.  (This was more like R-22 and
not the R-12 variety.  That, we used do dump into the atmosphere freely trying
to cool down components.)

I have resurrected many road-kill VCRs by using those cleaning techniques on
them.  I haven't as yet had to use soap, but using other than alcohol proves
beneficial.  Just don't get too liberal with any of the cleaning fluids.  By
the way, the freon was used to remove any residue left behind by the alcohol.

  6.7) Lubrication of a VCR

The short recommendation is: Don't add any oil or grease unless you
are positively sure it is needed.  Most parts in a VCR are lubricated
at the factory and do not need any further lubrication over their lifetime. 
Too much lubrication is worse then too little.  It is easy to add a drop
of oil but difficult and time consuming to restore a VCR that has taken a swim.

NEVER, ever, use WD40 in a VCR!  WD40 is not a good lubricant despite the
claims on the label.  Legend has it that the WD stands for Water Displacer -
which is one of the functions of WD40 when used to coat tools.  WD40 is much
too thin to do any good as a general lubricant and will quickly collect dirt
and dry up.  It is also quite flammable and a pretty good solvent - and there
is no telling what will be affected by this:

(From: Matthew Fries (freeze@visi.com)).

"I heard a horror story when I was in tech school about someone who heard a
 little squeaking inside the VCR when it was in PLAY mode, so he sprayed WD40 
 in through the tape door (front loading) and 'lubricated' the entire inside
 of the VCR. The students who were working on this took apart the entire
 mechanism, sprayed it clean with TF solvent (4 cans - there goes the ozone)
 and it still didn't work.  No surprise."

A light machine oil like electric motor or sewing machine oil should be
used for gear or wheel shafts.  A plastic safe grease like silicone grease
or Molylube is suitable for gear teeth, cams, and the roller guide tracks.

Unless the VCR was not properly lubricated at the factory (which is quite
possible), the only likely areas needing lubrication are the roller guide
tracks - clean and grease.  Sometimes you will find a dry capstan, motor,
lever, or gear shaft but this is less likely.

In general, do not lubricate anything unless you know there is a need.
Never 'shotgun' a problem by lubricating everything in sight!  You might
as well literally use a shotgun on the VCR!

  6.8) Head demagnetizing

With audio tape decks, demagnetizing is often recommended to improve
sound quality and frequency response.  There is some debate as to
how much benefit there is to this practice but if done properly,
there is little risk.  Demagnetizing removes the residual magnetic
fields that can build up on ferrous parts of the tape heads and
various guideposts and other parts in the tape path which may affect
frequency response.

For the following, do not go near the video head drum, only perform
demagnetization of the stationary A/C head, erase head, and guide
posts and rollers.  In my opinion, the video heads should almost never
need to be demagnetized.   The ferrite material from which they are
constructed is not prone to easily being magnetized like steel.

Use a small demagnetizer designed for a tape deck or cassette deck.
Do not use anything homemade that might be too powerful or a bulk
tape eraser which would certainly be too powerful.

Make sure the tip is covered with a soft material to prevent damage to
the finely polished surfaces in your VCR.

Turn power on to the demagnetizer when a couple of feet away from the VCR.
Then, slowly bring it in close and slowly go over all surfaces of anything
that the tape contacts or comes close to in the tape transport.  The key
word here is **slowly**.  Move fast, and you will make the magnetic
fields stronger.  When finished, slowly draw the demagnetizer away to a
distance of a couple of feet before turning it off.

Chapter 7) Cassette and Tape Loading Problems

  7.1) Cassette loading and eject problems

Cassette loading places the cassette into proper position on the tape
transport.  In a front loader, pushing the cassette gently into the
slot should cause a motor to take over and suck it in and down to rest
on indexing pins.  The mechanism that actually holds the cassette is called
the cassette basket. Several types of problems are possible: the VCR may
ignore you when you push the cassette in or press EJECT, or it may
spit it out immediately or cycle back and forth.  On a top loader, you do
most of the cassette loading manually, so the only likely problem will be 
if EJECT does not work.

If attempting to load a cassette produces no response (though the
VCR has power), then there could be a problem with the microswitch that
senses the presence of a cassette, the cassette loading motor (if separate
from the main motor), a slipping or broken belt, or a faulty driver
or other electronic problem.  Sometimes this could mean that the
microcontroller is confused due to a faulty mode switch or because
the mechanism somehow got into a peculiar state.  Manual cycling of
the cassette loading mechanism might reset it.  Gently push a cassette
in and turn the appropriate shaft or pulley by hand.  First, try this with the
VCR unplugged.  If nothing happens or you feel resistance, try the
other direction.  Assuming you find no problems - there is no significant
resistance to your turning and the cassette basket cycles from fully
ejected to fully seated on the transport baseplate, leave the cassette
basket in a partially loaded position and plug the VCR into the AC power
and turn it on (this may not be necessary depending on the design of your VCR).
It should now reset itself and either load or eject the cassette.
If there are still no signs of a response, a power supply, motor, or
electronic problem is likely.

Note: If this only happens with T160 (8 hour) tapes, it may be a problem
with the thinner tape confusing the sensors.  Avoiding these tapes is really
the best thing to do since they can cause all sorts of problems (especially
if they are an off-brand and of inferior quality to begin with).

If you hear a motor whirring but nothing happens, this is almost certainly a
slipping or broken belt or something blocking the proper movement a mechanical

If pushing a cassette into the VCR results in it being ejected as though
it tasted really bad (there may or may not be hesitation), or if the cassette
cycles back and forth without stopping, there could be several possible

If it stops part way during loading, does it pause as though the motor
is straining or just abort with no warning?  If the former, then check
carefully for foreign objects, or lack of lubrication.  A typical cause
is a belt slipping, usually not the idler in this case.  Help it out gently
and see if that will complete the cycle. Sometimes it is helpful to cycle
the mechanism by hand - turning the appropriate shaft or pulley and feeling
and watching for any place where it binds.  If the basket moves in the wrong
way or you feel any significant resistance, try the other direction.
Sometimes, the sticky cassette labels partially or totally peal off and
clog the works.  You may find a toy or rock inside carefully inserted by
your 3 year-old!  A bit of the cassette shell might have broken off and
jammed the mechanism just to confuse you!

If the microcontroller were detecting an abnormality, then it would abort
instantly but would most likely try to unload the tape before giving up
but not in all designs.  It is possible that if the expected behavior is
not produced by the end/beginning-of-tape sensors during cassette loading,
an abort could be initiated.  Therefore, these sensors could be suspect.
In some cases, the mode switch may be dirty or faulty.  A gear may have
broken some teeth or slipped a couple of teeth and the timing relationships
may be incorrect.  There may be a microswitch that is controlled by the
cassette basket position and this may be defective or dirty.

Similarly, if the cassette seems to be cycling in and out in an apparently
infinite loop, there may be an obstruction or the microcontroller is confused
by a bad sensor or the basket is out of synchronization with the rest
of the mechanism.  A squirt of contact cleaner into the microswitch sensor
and/or reflowing its bad solder connections may solve this type of problem.

Similar comments apply to cases where pressing the EJECT button
produces no response.  In particular, if the cassette was loaded
successfully and you just finished a thoroughly enjoyable movie,
the microcontroller may think the mechanism is not safe and is not
ejecting to protect your valuable tape from possible damage should
it not be fully retracted into the cassette.  As with loading, EJECT
may result in partial movement and shutdown or reloading the cassette
into the down position.  All the same causes apply.

  7.2) Ejecting a cassette from an uncooperative VCR

It is a common experience - the rental movie is due back at the video
store **now** but no matter how you press the EJECT button, yell, scream,
hold your breath, or jump up and down, the cassette refuses to be appear.

To remedy the underlying problem, see the sections on: "Cassette loading and eject problems" and other for appropriate information.  This section
only deals with getting the cassette out without damaging either your
valuable recording or VCR.

Under no circumstances should you force anything - both your tape and your
VCR will be history.

First, see if the VCR just got into a confused state - pull the plug and
patiently wait a minute or two.  This may reset the microcontroller and all
will be well.  These things happen.

If this is not successful, you will need to open up the VCR (unplug it
first!) and attempt to cycle the mechanisms by hand.  Probably both top and
bottom covers will need to be removed.  The following procedures assume that
there are no broken parts, foreign objects, or other damage which might
prevent manual cycling of the tape loading and cassette loading mechanism.
(Inspect for toys and rocks.)  Also note that some VCR designs use solenoids
to engage various operations.  This will complicate your task (to put it
mildly) as locating and activating the proper ones at the appropriate time
is, well, a treat.

1. Tape unloading: The first step is to determine if the tape has been unloaded
   from the video head drum back into the cassette.  If the tape is fully
   retracted into the cassette - there is no tape showing, then go on to
   step (2).  If not, you will need to figure out which shaft or pulley
   to turn to unload the tape.  Trace the linkage or gears that move
   the roller guides back to their motor - it may be the main capstan motor
   or a separate small motor used only for this purpose.  Rotate this in
   the direction which moves the roller guides back towards the cassette.
   It will take many revolutions - be persistent.  If you feel any significant
   resistance or the roller guides move out toward the drum, turn the other
   way.  The tape is fully unloaded when the roller guides are all the way
   into the cassette and the tape is straight across the cassette's
   stationary guideposts.

   If a single motor performs both the tape loading and cassette loading
   functions, stop turning as soon as you see the cassette start to rise
   and read the next section before proceeding.

   If you are not fully successful or if there is still a tape loop outside
   the cassette even once you have been turning for what seems to be an
   eternity, you can still try to eject the cassette but will need to be
   extra careful not to crinkle the tape as the cassette door closes with
   the tape sticking out.  Before proceeding on in this case, try to find
   a way to turn one of the reels to pull that tape back in as this will
   make your task a lot easier.  There may be an idler that swings between
   the two reels and this may be accessible from the bottom (the cassette
   will block it on top).

2. Cassette unloading.  Once the tape is fully retracted into the cassette,
   the cassette can be ejected safely.  If a tape loop is still sticking
   out of the cassette - and you care about the recording - you will need
   to be especially careful not to crinkle the tape as the cassette door
   closes.  It is usually not possible to get the cassette fully out
   without its door closing, so the best you can do is to make sure when this
   happens, the tape is flat across the gap.  With care, it should survive.

   On a top loader, there is usually a solenoid specifically for EJECT or
   a simple mechanical pushbutton.  Once the appropriate lever is pressed,
   the cassette should pop up - hold the basket with one hand as you do this
   to prevent any exposed tape loop from being crinkled.

   On a front loader, locate the cassette loading motor and begin turning
   it in the appropriate direction - this will be fairly obvious assuming
   there are no broken gear teeth or other broken parts and that something
   isn't totally jammed.  If this is the main capstan motor, then just
   continue turning as in (1).  Eventually the cassette should raise up
   and out.

   If you have a tape loop, be extra careful not to catch it on any
   guideposts or obstructions as you remove the cassette.  Then, wind it back
   into the cassette by turning one of the reels (you may have to depress the
   release button on the bottom of the cassette with a pencil - this is the
   small hole in the center near the label side.)

Assuming the tape is not torn and not badly crinkled, it should be fine.
If it is severely damaged, refer to the section: "Recovering damaged or broken tapes".

  7.3) VCR is confused - will not eject non-existent tape

If for some reason, the microcontroller gets confused and refuses to raise
the basket and there is no tape in the VCR, first, try pulling the plug
for a minute or two.  This may reset the error condition.  However, since
the mechanism is in an illegal state, the microcontroller may refuse to do
anything for fear of making things worse.

Assuming that the problem is still present, here are two suggestions:

* Manually turn the appropriate motor shaft with power off to put the
  mechanism through the eject cycle.  In many VCRs, this is as simple
  as turning the EJECT motor or possibly the main motor.  Be patient
  and gentle - it will take a while.

  If there is some underlying problem which caused the basket to be
  lowered without a cassette in place, than the VCR may return to the
  illegal state, do nothing, or do something else that is peculiar
  once power is restored or any button is pressed.

* Convince the microcontroller that a tape really is present when there
  is none.  You need to (1) cover the start/end sensor LED poking up in
  the center of the deck, (2) depress any other microswitches that sense
  tape present, press EJECT, and (3) possibly turn the non-driven reel
  by hand a bit while it is attempting to wind the tape loop back into
  the cassette.  Three or four hands are a definite asset.  Make sure
  you get your fingers out before they are caught!  Again, an underlying
  problem may produce unexpected results.

For additional info on initialization problems, see the section: "VCR is failing the power-up sequence".

Chapter 8) Fast Forward and Rewind Problems

  8.1) VCR will not fast forward and/or rewind

Usually, the owner will admit that the machine is pre-Jurassic and
has never been cleaned or serviced.

Anyway, rule out the idler tire as well as the idler clutch - if it
weakens, then the idler wheel does not press against the appropriate
reel with enough force to grip.

Is it s top or front loader?  If a top loader, you should be able to
trick it into playing a nonexistent tape by covering up the end-of-tape
light (the one sticking up in the middle) so that it will think there is
a tape inserted.  (In some models, there might also be a microswitch.)
This may permit you to see what is going on.

If a front loader, then it is tougher.  You need a cassette cheater
(see the section: "Cassette cheaters").  Then, with the cheater in place
happily fooling the VCR, feel the spindles while the machine is operating.
In FF or REW, you may find that they are not being driven or or being
driven very weakly.  Try to determine if the idler is even being pushed
into position or is hung up on something.

If there is any chance that it is the idler tire, try turning it inside-out.
The relatively protected inner (now outer) surface may grip well enough to
confirm the diagnosis.

Has it been serviced in the last 15 years?  The last 100 years?

  8.2) VCR aborts fast forward or rewind

In this case, the tape starts to move - possibly at a reasonable speed -
but then may shut down - possibly erratic or tape dependent.

Make sure the tape is not the problem - try another one.

If it starts the operation (as evidenced by whirring sounds and the tape
counter changing numbers) but at some point - perhaps near the end of
the tape - aborts and shuts down, then a worn idler tire, worn or broken
idler clutch, bad belt, or lubrication problem is likely.  See the section:
"VCR will not fast forward and/or rewind" as well as "Lubrication of a VCR".

With instant start transports - where the tape is maintained around
the video head drum for all but the fastest rewind, there could be
other control problems as well.

If the tape starts fast forwarding or rewinding properly (from a visual
inspection with the cover off) but the tape counter does not change value
and then the unit shuts down, a reel rotation sensor problem is likely.
See the section: "Reel rotation sensors".

If the operation aborts at the same location on only certain tapes, there
could be pinholes in the tape oxide coating allowing light to pass through
and confuse the sensors.  This happens mostly with T160 or old well worn
tapes.  If you can locate the problem area, you can try indelible ink on the
NON-oxide side of the tape but DO NOT use adhesive tape or glue.  Else,
discard the tape or live with its behavior.

  8.3) Noisy REW or FF

While these operations are never exactly quiet, when grinding or squeaking
noises are evident, it is time to at least consider the possibilities.

First confirm that the same thing happens with more than one cassette - it
could be defective.

(Portions from: Alan McKinnon (alan.mck@pixie.co.za)) and Oldguyteck

You get several types of noisy rewind:

* A high pitched squeak - dirt and/or dried or lost lubrication on reel
  spindles, remove both reel tables, clean and lubricate the shafts. On older
  machines you often find this as well on idler pulleys.

* Periodic 'eek-eek-eek' type noise, check for an out of round rotating part
  rubbing on something. No pat answers here, you have to get your eyes out
  and look.

* A grating metal on metal noise that sounds like car brake pads that should
  have been changed 5000 miles ago is always the capstan rubbing on its
  bearing. The only cure s a new motor. Ignore those that tell you to strip
  and clean the bearing. I've tried this trick at least 10 times on different
  machines - it won't last.  If a capstan motor is worn enough to howl, the
  shaft and bearing are way beyond repair. 

Miscellaneous causes:

* Cassette not seating properly and/or tape path alignment problems.  Press
  down on the cassette during REW or FF and see if it shuts up.

* Brake levers not disengaging completely, pads worn, or misadjusted.

* Missing fiber washers (who worked on the VCR last?); worn, broken, or
  distorted gears; other lubrication or dirt problems, etc.

* Bad bearings in main motor (usually older VCRs).

The list goes on and on.  In the end, the only way to narrow down the problem
will be with your eyes and ears!

  8.4) Tape rewinders

Should you buy a tape rewinder to save wear and tear on your VCR?
Take it or leave it.  I think they are good if your VCR is old and
for whatever reason has trouble with FF or REW.  However, sluggish
FF or REW may be a precursor to tape eating and should be addressed to
avoid an impending failure which may ruin a tape.  Rubber parts deteriorate
by just existing.  The surface layer oxidizes and use may actually
be good (don't quote me!).  I would not bother with a rewinder just to
prevent wear and tear on the motors or heads.  In many VCRs - particularly
older VCRs without real-time tape counters, the tape is totally retracted
into the cassette during high speed FF or REW and does not contact the heads
at all.  In newer VCRs with real-time counters, the tape will contact the
control head lightly but wear should not worth worrying about.  Wear and
tear on the motors is not a serious problem -  much less than playing a tape.
If the convenience of being able to rewind off-line is important to you, then
there may be no harm in using one.  However, some rewinders can be hard on
video tapes as they usually do not sense the clear leader but stop rewinding
when the tape tension increases at the end of the tape.  This may eventually
damage the tape and/or pull the tape from the takeup reel hub.  I have heard
of some crinkling the tape edge and actually mangling tapes.

(From: Jim Lagerkvist (jlager@tir.com)).

There are dozens of fast rewinder units claiming to save wear on your VCR.
The earliest ones snapped-off the clear leader from the hubs.  The later ones
with IR sensors simply made the real problem obvious:

Precious recordings are being damaged by a cheap transport screaming the tape
at high speed.  The tape is either creased or an edge is rippled (usually the
control track).

I have a long list of heartbroken people that have lost their archives with
these things; me included.  If a customer complains about a tape suddenly not
viewing well, ask if they use one of these things.

Chapter 9) Play and Record Mechanical Problems

  9.1) VCR refuses to record

If efforts to record (directly or via the timer) are totally ignored or
cause the cassette to be ejected, then the record protect tab on
the cassette may be broken off or the record protect sense switch in the
VCR may be dirty or defective.  This switch sits just under the cassette
slot (on front loaders).  Locate it by referencing the tab position on the
loaded cassette.  It can easily be tested with an ohmmeter - if you can get
to it.  To confirm, short out or disconnect (which you will need to do
depends on the design of your VCR) the appropriate wires (maybe
there is a connector - this could have bad contacts as well) and see if
the VCR is more cooperative.

  9.2) VCR aborts play or record during startup or shortly thereafter

This is a problem with the process called 'tape loading' - pulling the
tape loop out of the cassette and wrapping it around the spinning video drum,
engaging the capstan and pinch roller and reel rotation.

Check all the belts above and below the deck.  Belts can appear to
be firm but if they do not return immediately to their relaxed length when
you stretch them 25%, they will need to be replaced.

With the cover off, observe the behavior when you hit play.  (You may need
to put a piece of cardboard over the cassette to block external light from
interfering with the start/end tape sensors).  Assuming this is a basic VCR
(no instant start features), you should see:

1. The video head drum begins to spin.

2. the roller guides move smoothly on the tracks, wind the tape around
   the drum, and stop snuggly pressed against the 'V-Stopper' at the end
   of the tracks.

3. The pinch roller moves into position and presses the tape against the

4. The tape begins to move and is wound up by the takeup reel.

5. The picture and sound appear on the TV.

With a 'rapid or quick start' (or it may be called something else) transport,
the tape moves to a half-loaded position when the cassette is inserted.
This is at an intermediate position partially pulled out of the cassette
but not wrapped around the drum.  On VCRs with a real-time counter and/or
index search capabilities, the tape will be in contact with the control head.

With an 'instant start' transport, the tape will fully load around the
spinning drum when the cassette is inserted but the capstan will not engage and
no tension will be applied to the tape until you press PLAY or REC.  (After
about 5 minutes, the drum will stop and it may unload to the half loaded
or unloaded position.)

Note that for VCRs with a real-time counter and/or index search capabilities,
the tape must be in contact with the control head (but not the video heads)
for all relevant modes.  These VCRs (which include many modern units)
must therefore pull the tape at least partly out of the cassette.

In all cases, the completion of the sequence results in approximately
the same mechanical configuration during PLAY.

Several likely possibilities when it shuts down:

1. Everything occurs as above, picture and sound appear for a few seconds,
   but then the VCR unloads the tape, ejects the cassette, goes into REW
   mode, stops, or shuts off.  Two common causes:

   * The takeup reel does not turn and tape spills into the machine.  This is
     sensed by the microcontroller which aborts record or play and attempts
     to save your valuable cassette.  Most likely cause: old/dirty idler
     tire.  As a test, turn the idler tire inside-out.  The fresh surface will
     now work well enough to confirm this diagnosis and will continue working
     long enough for your replacement idler tire to arrive.  See the section:
     "General guide to VCR cleaning and rubber parts replacement".

   * The takeup reel is turning properly but one of the reel rotation sensors
     or its electronics is defective.  As a test, check to see if the tape
     counter is changing at any time during the loading and abort process.
     Non-real-time tape counters usually get their pulses from this same
     sensor.  (Real-time counters operate off of the A/C head control pulses
     and therefore would not be affected by a defective reel sensor).  Some
     older VCRs used a belt driven counter - the belt may have broken or fallen
     off.  Most newer VCRs use an optical sensor which may simply be dirty.
     See the section: "Reel rotation sensors".

2. The roller guides are getting hung up and not fully loading the tape
   either as a result of an obstruction or dried up grease, or a slipping
   tape loading belt (often accompanied by an spine tingling squeal).
   Parts may have broken or fallen off of the roller guide assemblies
   preventing them from fully engaging the 'V-Stoppers'.  A similar
   fault may prevent the capstan from fully engaging against the tape
   and pinch roller.  A toy, candy, or a plastic bit of a cassette shell
   may be jamming something.

3. The mode switch sensor is dirty or defective and confusing the poor
   microcomputer as to the position of the loading mechanism.  In this case,
   the loading process may stop half way, pause, and then unload as in
   (1) or (2), above.  Or, it may do almost anything.  See the section
   on: "Erratic behavior in various modes".

4. Some other condition such as the end-of-tape sensor thinking that
   you are at the end of the tape is aborting the tape loading process.
   This might be indicated by a sudden reversal and shutdown rather than
   a pause (usually accompanied by the sound of a motor whirring) at some
   point attempting to complete part of the cycle.  For problems with
   record in particular, the record protect tab switch may be dirty or
   worn resulting in random aborts.

5. Electronic problems like bad grounds or other bad connections are also
   possible.  Since with some models, (a number of JVC manufactured VCRs,
   for example) ground integrity is via screws through the mainboard, should
   these loosen, erratic behavior may result.  Tighten the screws.

6. A defective microcontroller or other logic could also be at fault but
   this is less likely than any of the preceding.

  9.3) VCR aborts play or record at random times or near end of tape

In this case, the VCR starts to play or record but, say, an hour later,
shuts down for no good reason - at least not as a result of a command
you thought you issued.

Make sure the tape is not the problem - try another one.  There may be spots
on the tape where the oxide has come off resulting in pinhole (or larger) areas
which are activating the end-sensors.

Confirm that you are using the proper play or record modes - not OTR (One Time
Record) or other timed play or record modes which will likely operate in
increments of 15 minutes depending on how many times you press the button.
In addition, on certain VCRs, if the program timer is enabled with a program
setting that has its stop time occur while you are using the VCR - even if
the record operation has been aborted by pressing the stop button - the VCR
will shut down.

If play or record aborts at the same location on only certain tapes, there
could be pinholes in the tape oxide coating allowing light to pass through
and confuse the sensors.  This happens mostly with T160 or old well worn
tapes.  If you can locate the problem area, you can try indelible ink on the
NON-oxide side of the tape but DO NOT use adhesive tape or glue.  Else,
discard the tape or live with its behavior.

Finally, make sure you are not using any 'insert editing' modes which require
a previously laid down control track and would abort once blank tape was
reached.  See the section: "Recording stops at random times on previously used tapes".

Once all the obvious problems and cockpit errors have been eliminated,
mechanical problem still likely even though the VCR does not abort
immediately.  A worn idler tire, worn or defective idler clutch, bad belt,
or improperly adjusted backtension, are all possibilities.

This is particularly likely if the problem is more likely to occur or only
happens near the end of tapes as the required takeup reel torque is greater
and any of the above mechanical problems will be exacerbated.

With instant start transports - where the tape is maintained around
the video head drum for all but the fastest rewind, there could be
other control problems as well.

If the operation starts properly (as indicated by a changing picture on the
TV in play or from a visual inspection with the cover off) but the tape
counter does not change value and then the unit shuts down, a reel
rotation sensor problem is likely. See the section: "Reel rotation sensors".

This could still be due to problems similar to those which cause an
immediate abort if some components or connections are marginal.  Also
see the section: "VCR aborts play or record during startup or shortly thereafter".

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Written by Samuel M. Goldwasser. | [mailto]. The most recent version is available on the WWW server http://www.repairfaq.org/ [Copyright] [Disclaimer]