JVC HR-A57U VCR autoshuts off

[Apollo]

Hie all,

I have a 3-year old JVC HR-A57U VCR which has been well-used but
well-maintained. When I play a cassette, the VCR plays for 2-5 seconds
and shuts down. Sometimes a few more tries gets the VCR to play
normally, sometimes it doesn't. Fast-forwarding, rewinding and pausing
my tapes worsens the problem. From my experience with audio cassette
players, I'm guessing this is some self-protection mechanism to stop
the VCR from chewing tape. This intermittent problem happens with all
cassettes - both store-bought and home-taped; both SHORT-PLAY and
EXTENDED-PLAY recordings; new and old tapes etc. Updating channels,
setting the timer recording and the clock and all the menus all work
fine; just the cassette won't play.

What can I do about this problem since repair shops are so expensive
compared to the cost of a new one? I'm a VCR-newbie but a
computer-techie so I'm very comfortable following instructions,
finding and tweaking/replacing components.

Thanks..

 

[Mark D. Zacharias]

"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405191731.434c1e55@posting.google.com...

Hie all,

I have a 3-year old JVC HR-A57U VCR which has been well-used but
well-maintained. When I play a cassette, the VCR plays for 2-5 seconds
and shuts down. Sometimes a few more tries gets the VCR to play
normally, sometimes it doesn't. Fast-forwarding, rewinding and pausing
my tapes worsens the problem. From my experience with audio cassette
players, I'm guessing this is some self-protection mechanism to stop
the VCR from chewing tape. This intermittent problem happens with all
cassettes - both store-bought and home-taped; both SHORT-PLAY and
EXTENDED-PLAY recordings; new and old tapes etc. Updating channels,
setting the timer recording and the clock and all the menus all work
fine; just the cassette won't play.

What can I do about this problem since repair shops are so expensive
compared to the cost of a new one? I'm a VCR-newbie but a
computer-techie so I'm very comfortable following instructions,
finding and tweaking/replacing components.

Thanks..

If there's lots of smoke and or dust / dirt in the environment, the optical
motion-sensing may be a problem. Lucite light pipes dirty, infra-red
emitting LED and photo-transistors can be covered up.

Just a thought....


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.

 

[Apollo]

Thanks for your reply. I use the VCR in a regular apartment with no
smoke and tolerable dust. When I last cleaned the track that the tape
follows, I removed quite a bit of dirt. How can I find, check and
clean the lucite light pipes, IR LED and phototransistors?

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message news:<2h3dhrF8gffaU1@uni-berlin.de>...

If there's lots of smoke and or dust / dirt in the environment, the optical
motion-sensing may be a problem. Lucite light pipes dirty, infra-red
emitting LED and photo-transistors can be covered up.

Just a thought....


Mark Z.

"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405191731.434c1e55@posting.google.com...
Hie all,

I have a 3-year old JVC HR-A57U VCR which has been well-used but
well-maintained. When I play a cassette, the VCR plays for 2-5 seconds
and shuts down. Sometimes a few more tries gets the VCR to play
normally, sometimes it doesn't. Fast-forwarding, rewinding and pausing
my tapes worsens the problem. From my experience with audio cassette
players, I'm guessing this is some self-protection mechanism to stop
the VCR from chewing tape. This intermittent problem happens with all
cassettes - both store-bought and home-taped; both SHORT-PLAY and
EXTENDED-PLAY recordings; new and old tapes etc. Updating channels,
setting the timer recording and the clock and all the menus all work
fine; just the cassette won't play.

What can I do about this problem since repair shops are so expensive
compared to the cost of a new one? I'm a VCR-newbie but a
computer-techie so I'm very comfortable following instructions,
finding and tweaking/replacing components.

Thanks..

 

[Mark D. Zacharias]

Different models are different - the start and end-detect phototransistor,
for example often are in fairly tall plastic posts with only a slit for the
IR to get in there. Others have a clear LED-looking phototransistor nestled
at the main circuit board on both sides of the deck, with more light-piping
to carry the center LED output down to them.

Anyway. Doesn't sound like these are your problem, but the center LED is
right about in the middle of where the tape sets down into the mechanism.
The LED or it's light-pipe extends up into the cassette shell when the tape
is loaded. This same LED shines through a couple openings in the cassette
shell, so it can shine through clear leader-tape at the beginning and end of
the tape, triggering the phototransistors I just mentioned.

Motion sensing may or may not make use of the same center LED. As one or
both reel hubs rotate, there will be some form of motion sensing. Either
optical, in which case it may take advantage of the same center LED piped
over to a reel hub, with a phototransistor there, or there may be a
dedicated LED emitter-phototransistor pair, or it could use a Hall-effect
sensor. Depends entirely on the model, and your problem may not even be in
this area.

If an LED or phototransistor is cleanable, you can just use a cotton swab
moistened with window cleaner, then use the dry side to get any excess.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405201557.1b35c3a2@posting.google.com...

Thanks for your reply. I use the VCR in a regular apartment with no
smoke and tolerable dust. When I last cleaned the track that the tape
follows, I removed quite a bit of dirt. How can I find, check and
clean the lucite light pipes, IR LED and phototransistors?

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message
news:<2h3dhrF8gffaU1@uni-berlin.de>...



If there's lots of smoke and or dust / dirt in the environment, the
optical
motion-sensing may be a problem. Lucite light pipes dirty, infra-red
emitting LED and photo-transistors can be covered up.

Just a thought....


Mark Z.

"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405191731.434c1e55@posting.google.com...
Hie all,

I have a 3-year old JVC HR-A57U VCR which has been well-used but
well-maintained. When I play a cassette, the VCR plays for 2-5 seconds
and shuts down. Sometimes a few more tries gets the VCR to play
normally, sometimes it doesn't. Fast-forwarding, rewinding and pausing
my tapes worsens the problem. From my experience with audio cassette
players, I'm guessing this is some self-protection mechanism to stop
the VCR from chewing tape. This intermittent problem happens with all
cassettes - both store-bought and home-taped; both SHORT-PLAY and
EXTENDED-PLAY recordings; new and old tapes etc. Updating channels,
setting the timer recording and the clock and all the menus all work
fine; just the cassette won't play.

What can I do about this problem since repair shops are so expensive
compared to the cost of a new one? I'm a VCR-newbie but a
computer-techie so I'm very comfortable following instructions,
finding and tweaking/replacing components.

Thanks..

 

[Mark D. Zacharias]

P.S.

As to checking these devices, this can be tricky, and would certainly
require at least a digital voltmeter, and hopefully a schematic.
For example a phototransistor exposed to a light source may toggle between 0
and 5 volts. This is fairly common. But if the output drives another
transistor directly, the output may clamp at .6 volts. This is why service
literature is important. It allows a knowledgeable tech not only to find the
affected parts, but to interpret his readings.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405201557.1b35c3a2@posting.google.com...

Thanks for your reply. I use the VCR in a regular apartment with no
smoke and tolerable dust. When I last cleaned the track that the tape
follows, I removed quite a bit of dirt. How can I find, check and
clean the lucite light pipes, IR LED and phototransistors?

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message
news:<2h3dhrF8gffaU1@uni-berlin.de>...



If there's lots of smoke and or dust / dirt in the environment, the
optical
motion-sensing may be a problem. Lucite light pipes dirty, infra-red
emitting LED and photo-transistors can be covered up.

Just a thought....


Mark Z.

"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405191731.434c1e55@posting.google.com...
Hie all,

I have a 3-year old JVC HR-A57U VCR which has been well-used but
well-maintained. When I play a cassette, the VCR plays for 2-5 seconds
and shuts down. Sometimes a few more tries gets the VCR to play
normally, sometimes it doesn't. Fast-forwarding, rewinding and pausing
my tapes worsens the problem. From my experience with audio cassette
players, I'm guessing this is some self-protection mechanism to stop
the VCR from chewing tape. This intermittent problem happens with all
cassettes - both store-bought and home-taped; both SHORT-PLAY and
EXTENDED-PLAY recordings; new and old tapes etc. Updating channels,
setting the timer recording and the clock and all the menus all work
fine; just the cassette won't play.

What can I do about this problem since repair shops are so expensive
compared to the cost of a new one? I'm a VCR-newbie but a
computer-techie so I'm very comfortable following instructions,
finding and tweaking/replacing components.

Thanks..

 

[Apollo]

Thanks Mark,

Yikes, I know when I am beat. I'll leave this to the professionals
since I don't have the tools to pull it off. Or maybe just get a new,
cheap brand downtown..

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message news:<2h64nvF70cmsU1@uni-berlin.de>...

P.S.

As to checking these devices, this can be tricky, and would certainly
require at least a digital voltmeter, and hopefully a schematic.
For example a phototransistor exposed to a light source may toggle between 0
and 5 volts. This is fairly common. But if the output drives another
transistor directly, the output may clamp at .6 volts. This is why service
literature is important. It allows a knowledgeable tech not only to find the
affected parts, but to interpret his readings.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405201557.1b35c3a2@posting.google.com...
Thanks for your reply. I use the VCR in a regular apartment with no
smoke and tolerable dust. When I last cleaned the track that the tape
follows, I removed quite a bit of dirt. How can I find, check and
clean the lucite light pipes, IR LED and phototransistors?

"Mark D. Zacharias" <mzacharias@yis.us> wrote in message
news:<2h3dhrF8gffaU1@uni-berlin.de>...



If there's lots of smoke and or dust / dirt in the environment, the
optical
motion-sensing may be a problem. Lucite light pipes dirty, infra-red
emitting LED and photo-transistors can be covered up.

Just a thought....


Mark Z.

"Apollo" <socialite1000@hotmail.com> wrote in message
news:de5869c3.0405191731.434c1e55@posting.google.com...
Hie all,

I have a 3-year old JVC HR-A57U VCR which has been well-used but
well-maintained. When I play a cassette, the VCR plays for 2-5 seconds
and shuts down. Sometimes a few more tries gets the VCR to play
normally, sometimes it doesn't. Fast-forwarding, rewinding and pausing
my tapes worsens the problem. From my experience with audio cassette
players, I'm guessing this is some self-protection mechanism to stop
the VCR from chewing tape. This intermittent problem happens with all
cassettes - both store-bought and home-taped; both SHORT-PLAY and
EXTENDED-PLAY recordings; new and old tapes etc. Updating channels,
setting the timer recording and the clock and all the menus all work
fine; just the cassette won't play.

What can I do about this problem since repair shops are so expensive
compared to the cost of a new one? I'm a VCR-newbie but a
computer-techie so I'm very comfortable following instructions,
finding and tweaking/replacing components.

Thanks..